bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacokinetics of Dexamethasone Solution following Intratympanic Injection in Guinea Pig and Sheep
Authors: Wang Xiaobo , Fernandez Rayne , Dellamary Luis , Harrop Anne , Ye Qiang , Lichter Jay , Lau David , LeBel Carl , Piu Fabrice
Published: October 2010

Information on inner ear pharmacokinetics is limited in the literature, especially in large animals and in humans. A preliminary study was designed to explore the differences in inner ear exposure between guinea pigs and sheep following a single intratympanic injection of a 2% dexamethasone sodium phosphate solution. In both species, significant levels of dexamethasone were observed in the perilymph within 1 h, and decreasing by 50- to 100-fold within 12 h. Overall, the exposure to dexamethasone in the inner ear was significantly lower in sheep by 17- to 27-fold than in guinea pigs. Systemic and CNS exposure were minimal in both species as indicated by the low drug levels observed in plasma and CSF. Altogether, the preliminary evidence presented herein suggests the sheep as a practical and acceptable animal model to study the inner ear pharmacokinetics of drug candidates in large mammals and its potential towards extrapolation to human exposure.
Systemic and Cellular Reflections on Ageing and the Circadian Oscillator – A Mini-Review
Authors: Brown Steven A. , Pagani Lucia , Cajochen Christian , Eckert Anne
Published: October 2010

From circulation to digestion to excretion, a circadian clock synchronizes most aspects of mammalian physiology with the solar day. During normal ageing, this daily coordination gradually erodes, and during pathological ageing such erosion is exacerbated. Recent experiments suggest that therapies aimed at sustaining circadian function increase quality of life in elderly patients. Hence, a better understanding of the interactions between the circadian clock and ageing – at both cellular and systemic levels – could lead to direct benefits for aged individuals.
Effects of Papaverine on Twitches in Mouse Diaphragm
Authors: Kaneda Takeharu , Hayasaka Ryutaro , Nagai Yuta , Tajima Tsuyoshi , Urakawa Norimoto , Nakajyo Shinjiro , Shimizu Kazumasa
Published: October 2010

This study examined the inhibitory effects of papaverine on twitches directly elicited by electrical stimulation of the mouse diaphragm. Papaverine (3–100 µM) inhibited twitches in a dose-dependent manner. Papaverine increased the cyclic adenosine monophosphate (cAMP) but not cyclic guanosine monophosphate (cGMP) content. IBMX, Db-cAMP and 8-br-cGMP did not affect twitches, whereas verapamil and NaCN inhibited twitches. Increases in extracellular Ca2+ removed the twitch inhibition caused by verapamil but not that caused by papaverine. Papaverine (30 and 100 µM) and NaCN (1 mM) decreased creatine phosphate and ATP contents. These results suggest that the relaxing effects of papaverine on mouse diaphragm are mainly due to inhibition of aerobic energy metabolism.
Contribution of Cyclooxygenase-Dependent Mechanisms to Contractile Responses to Donepezil in the Rat Urinary Bladder
Authors: Shimizu Naoko , Nakahara Tsutomu , Kubota Yuko , Sakamoto Kenji , Ishii Kunio
Published: October 2010

Donepezil, an inhibitor of acetylcholinesterase, is used to improve cholinergic neurotransmission and cognitive function in Alzheimer’s disease. In the present study, contractile effects of donepezil on the rat urinary bladder were examined and compared with those of the nonselective cholinesterase inhibitor neostigmine. Both donepezil and neostigmine produced concentration-dependent contractile responses of the isolated rat urinary bladder strips. The neostigmine-induced contractions were abolished by atropine. However, donepezil produced contractions of urinary bladders partly through atropine-insensitive mechanisms. The atropine-resistant component of donepezil-induced contraction was significantly reduced by the cyclooxygenase inhibitor indomethacin. These results suggest that cyclooxygenase-derived prostanoids contribute, at least in part, to contractile effects of donepezil in the rat urinary bladder.
Proinflammatory Activation of Peripheral Blood Mononuclear Cells in Patients with Vestibular Neuritis
Authors: Kassner Stefan S. , Schöttler Sarah , Bonaterra Gabriel A. , Stern-Straeter Jens , Hormann Karl , Kinscherf Ralf , Gössler Ulrich R.
Published: October 2010

Vestibular neuritis (VN) is characterized by acute vertigo with spontaneous nystagmus and is often accompanied by vegetative symptoms. While the pathogenetic process leading to this disease is widely unknown, increasing evidence exists that a proinflammatory environment is responsible for the induction and progression of VN. Twelve patients with acute VN and 12 healthy, age-matched individuals were included in this study. In addition to routine blood parameters, plasma levels of soluble CD40 receptor/ligand (sCD40/sCD40L) were determined by ELISA. Moreover, peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll density gradient. Afterwards, in CD14 (monocytes), CD68 (macrophages), CD3 (T lymphocytes) or CD19 (B lymphocytes) subpopulations, proinflammatory [CD40, tumor necrosis factor-α (TNF-α), and COX-2], proapoptotic [caspase-3, and poly(adenosine diphosphate ribose) polymerase] and proadhesive (CD38) proteins were measured by 2-color fluorescence-activated cell sorter analyses. In comparison to healthy individuals, patients with acute VN revealed significantly elevated plasma levels of C-reactive protein, whereas plasma levels of sCD40 and sCD40L, as well as cholesterol/triglyceride status were similar. However, we found a significant elevation of the percentage of proinflammatory CD40+, TNF-α+, COX-2+ or CD38+ PBMCs. Elevation of proinflammatory and proadhesive proteins in PBMCs of patients with acute VN in parallel with an acute phase response may contribute to disease induction and progression and, thus, may be suggested as a novel therapeutic target.
Utility of the Kurashiki Prehospital Stroke Scale for Hyperacute Stroke
Authors: Iguchi Yasuyuki , Kimura Kazumi , Watanabe Masao , Shibazaki Kensaku , Aoki Junya
Published: October 2010

Backgrounds: Our aim was to confirm the utility of paramedics using the Kurashiki Prehospital Stroke Scale (KPSS), with a maximum score of 13, for patients who may be eligible for administration of intravenous tissue plasminogen activator (IV t-PA). Methods: The subjects comprised acute stroke and transient ischemic attack (TIA) patients transferred to our hospital by paramedics. We analyzed correlations between KPSS and the National Institutes of Health Stroke Scale (NIHSS). Patients admitted within 3 h of onset were categorized into 2 groups: KPSS ≧4 and KPSS <4. We compared the proportion of patients receiving IV t-PA between the groups. Results: Among 430 consecutive patients (mean age = 73 years; 266 men), paramedics recorded KPSS for 256 patients (59.5%). Excellent correlation was observed between KPSS and NIHSS in all 256 patients (R = 0.766; p < 0.001) and in 94 patients (ischemic stroke and TIA with symptoms on admission) admitted within 3 h of onset (R = 0.706; p < 0.001). Among these 94 patients, IV t-PA was more frequently given in the KPSS ≧4 group (30 of 58 patients, 51.7%) than in the KPSS <4 group (5 of 36 patients, 13.9%; p < 0.001). Arterial occlusion was more frequently observed in the KPSS ≧4 group (57.9 vs. 31.4%, p = 0.018). KPSS ≧4 was independently associated with administration of IV t-PA (odds ratio = 4.7; 95% confidence interval = 1.5–14.6, p = 0.008). Conclusion: Reliable concordance between KPSS and NIHSS was found in acute stroke and TIA patients. KPSS ≧4 represents a good score to indicate prospective t-PA patients among those admitted within 3 h of stroke onset.
Do Vascular Risk Factors Explain the Association between Socioeconomic Status and Stroke Incidence: A Meta-Analysis
Authors: Kerr Gillian D. , Slavin Helen , Clark Donna , Coupar Fiona , Langhorne Peter , Stott David J.
Published: October 2010

Background: Reduced socioeconomic status (SES) is associated with an increased risk of stroke, although the mechanism is not clear. It may be that those with lower SES have a greater burden of classic vascular risk factors. Methods: Our aim was to quantify the extent to which classic vascular risk factors explain the association between SES and stroke incidence. We conducted a systematic review and meta-analysis of studies examining the association of SES and stroke incidence, where classic vascular risk factors were considered. Searching MEDLINE, EMBASE and the Cochrane Library from 1980 onwards we identified 17 studies, 12 of these studies provided sufficient information to allow a meta-analysis. From each study the increased risk of stroke incidence, where the lowest socioeconomic category was compared with the highest, was recorded and pooled. The stroke incidence risks, adjusted for grouped classic risk factors, were also pooled. Review Manager 5 software was used for all analyses and results were analysed using hazard ratios (HR, 95% confidence interval, 95% CI) with a random effects model. Results: Those with a lower SES were more likely to have a stroke (HR 1.67; 95% CI 1.46–1.91). Additional risk was reduced, but not eliminated, when classic vascular risk factors were adjusted for (HR 1.31; 95% CI 1.16–1.48). Conclusion: Low SES is associated with an increased risk of stroke that is partly explained by known classic vascular risk factors.
Moderate Physical Training Attenuates the Effects of Perinatal Undernutrition on the Morphometry of the Splenic Lymphoid Follicles in Endotoxemic Adult Rats
Authors: Moita Luanna , Lustosa Marinaldo Freire , Tobias Silva Amanda Theresa , Pires-de-Melo Iracema Hermes , Vieira de Melo Roberto José , de Castro Raul Manhães , de Pontes Filho Nicodemos Teles , Ferraz José Cândido , Leandro Carol Góis
Published: October 2010

Background/Aims: Physical training is a well-known inducer of positive physiological adaptations. The effects of moderate physical training on the morphometry of splenic lymphoid follicles of endotoxemic rats submitted to a perinatal low-protein (LP) diet were evaluated. Methods: Male Wistar rats were divided into two groups according to their mother’s diet (17% casein, control, C) and, undernourished (8% casein, LP diet). On postnatal day 63, the animals were submitted to moderate physical training (8 weeks, 5 days·week–1, 60 min·day–1, at 70% of VO2max). After the physical training period, half of each group received an injection of either lipopolysaccharide (LPS) or saline. Plasma corticosterone concentration, blood differential leukocyte counts and splenic morphometric parameters were analyzed. Results: In undernourished toxemic (LP + LPS), LPS increased plasma corticosterone concentrations, but not in previously trained (LP + T + LPS) animals. Neutrophilia and lymphopenia in response to LPS was more pronounced in pups from undernourished mothers (LP + LPS). LP + LPS animals showed a higher increment (47.4%) in the number of lymphoid follicles, a reduction in the number and size of the splenic follicles, and in the marginal zone area. Those alterations were attenuated in trained animals (LP + T + LPS). Conclusions: Physical training attenuates the effects of nutritional programming on the splenic microanatomy by a mechanism that involves the hypothalamic-pituitary-adrenal axis.
Hemorrhagic Pure Sensory Strokes in the Thalamus and Striatocapsular Area: Causes, Clinical Features and Long-Term Outcome
Authors: Tong Dao-Ming , Zhou Ye-Ting , Wang Guang-Sheng , Chen Xiao-Dong , Yang Tong-Hui , Chang Chun-Hong , Wang Yuan-Wei
Published: October 2010

Background: Although there have been sporadic reports of patients with hemorrhagic pure sensory strokes (HPSS) in the thalamus and striatocapsular areas, the causes, clinical featuring and long-term outcome have not been adequately investigated. Methods: We recruited 7 consecutive patients without hemiparetic stroke who had HPSS in the thalamic and striatocapsular areas. A CT scan was performed to verify brain imaging patterns, and their causes, clinical featuring and long-term outcome were observed. Results: We studied 7 patients who had HPSS in the thalamic and striatocapsular areas as seen in CT scans. The 7 patients had hypertension, and small hemorrhages were found in the thalamus of 2 patients and in the posterior quarter of the posterior limb of the internal capsule in 4 patients; only 1 patient had a microhemorrhage in the thalamus. The volume of the hemorrhages ranged from 0.3 to 6.3 ml, with a mean of 2.3 ± 1.9 ml. Three patients showed a decreased sense of spinothalamic modality, and position and vibration senses were spared. Four patients showed a sensory deficit of both spinothalamic and medial lemniscal type. The outcomes were excellent and without post-stroke pain in all patients. Conclusion: HPSS in the thalamus and striatocapsular area are usually small hemorrhages or microhemorrhages from rupturing of the microvessels or the branches of small vessels. HPSS only have an impact on the adjacent sensory nucleus or pathway, and have a good outcome without post-stroke pain.
Effects of Hydroxyethyl Starch, Gelatin and Dextran on Endothelium-Derived Relaxation in Porcine Coronary Arteries
Authors: Dagtekin Oguzhan , Klisa Maite Ann-Katrin , Gerbershagen Hans Jürgen , Marcus Hanke , Krep Henning , Teschendorf Peter , Fischer Jürgen Hartmut
Published: October 2010

Background: In a pilot study we could show that hydroxyethyl starch (HES) induced a significant reduction of endothelium-dependent relaxation (EDR) and the endothelium-derived hyperpolarizing factor (EDHF). In this follow-up study we investigated whether this effect of HES was dose-dependent and whether it could be replicated with other colloids like dextran (DX) and gelatin (GL). Methods: Rings of fresh porcine coronary arteries were consecutively tested with or without HES, DX or GL (5, 10, or 20 mg/ml). Indomethacin was added in all measurements to eliminate prostacyclin effects. Prostaglandin F2α was used for contraction and bradykinin (BK, 10–10 to 10–5M) for inducing EDR. After blocking nitric oxide (NO) by N-nitro-L-arginine (L-NNA), the experiments were repeated to assess the EDHF-mediated relaxation response to BK. Results: HES induced a reduction in EDR for the BK concentrations of 10–8 and 10–7M (n = 10; p < 0.05). After NO blockage with L-NNA, the relaxation response was reduced especially for the BK concentrations of 10–6 and 10–5M (p < 0.05). GL showed a reduction in EDR with or without NO blockage with L-NNA especially for the BK concentrations of 10–6 and 10–5M (n = 14; p < 0.05). DX induced a significant reduction in EDR for the BK concentrations of 10–7 and 10–6M (n = 12; p < 0.05). After NO blockage with L-NNA, the relaxation response was reduced especially for the BK concentrations of 10–6 and 10–5M (p < 0.05). Conclusion: For clinically relevant concentrations of HES, DX and GL a significant reduction in both NO-induced and NO-/prostacyclin-independent EDR can be found in epicardial coronary arteries of the pig.
Combined Use of Pulsed Arterial Spin-Labeling and Susceptibility-Weighted Imaging in Stroke at 3T
Authors: Viallon Magalie , Altrichter Stephen , Pereira Vitor Mendes , Nguyen Duy , Sekoranja Lucka , Federspiel Andrea , Kulcsar Zsolt , Sztajzel Roman , Ouared Rafik , Bonvin Christophe , Pfeuffer Josef , Lövblad Karl-Olof
Published: October 2010

Background and Purpose: In acute stroke it is no longer sufficient to detect simply ischemia, but also to try to evaluate reperfusion/recanalization status and predict eventual hemorrhagic transformation. Arterial spin labeling (ASL) perfusion may have advantages over contrast-enhanced perfusion-weighted imaging (cePWI), and susceptibility weighted imaging (SWI) has an intrinsic sensitivity to paramagnetic effects in addition to its ability to detect small areas of bleeding and hemorrhage. We want to determine here if their combined use in acute stroke and stroke follow-up at 3T could bring new insight into the diagnosis and prognosis of stroke leading to eventual improved patient management. Methods: We prospectively examined 41 patients admitted for acute stroke (NIHSS >1). Early imaging was performed between 1 h and 2 weeks. The imaging protocol included ASL, cePWI, SWI, T2 and diffusion tensor imaging (DTI), in addition to standard stroke protocol. Results: We saw four kinds of imaging patterns based on ASL and SWI: patients with either hypoperfusion and hyperperfusion on ASL with or without changes on SWI. Hyperperfusion was observed on ASL in 12/41 cases, with hyperperfusion status that was not evident on conventional cePWI images. Signs of hemorrhage or blood-brain barrier breakdown were visible on SWI in 15/41 cases, not always resulting in poor outcome (2/15 were scored mRS = 0–6). Early SWI changes, together with hypoperfusion, were associated with the occurrence of hemorrhage. Hyperperfusion on ASL, even when associated with hemorrhage detected on SWI, resulted in good outcome. Hyperperfusion predicted a better outcome than hypoperfusion (p = 0.0148). Conclusions: ASL is able to detect acute-stage hyperperfusion corresponding to luxury perfusion previously reported by PET studies. The presence of hyperperfusion on ASL-type perfusion seems indicative of reperfusion/collateral flow that is protective of hemorrhagic transformation and a marker of favorable tissue outcome. The combination of hypoperfusion and changes on SWI seems on the other hand to predict hemorrhage and/or poor outcome.
Restless Legs Syndrome and Pregnancy: A Questionnaire Study in the Poitiers District, France
Authors: Neau Jean-Philippe , Porcheron Adeline , Mathis Stéphane , Julian Adrien , Meurice Jean-Claude , Paquereau Joël , Godeneche Gaëlle , Ciron Jonathan , Bouche Gauthier
Published: October 2010

Aims: To perform a large and detailed epidemiologic study on restless legs syndrome (RLS) during pregnancy in a European country. Methods: A cross-sectional questionnaire survey. The questionnaire was distributed by the medical staff in different outpatient waiting rooms (obstetrics and gynecology department of the university hospital, obstetrics and gynecology department of a private clinic, private midwives, private obstetrician-gynecologists, radiological centers before fetal ultrasound examination and general practitioners) in a French town and its surrounding area (200,000 inhabitants): A woman was considered affected if she met the International RLS Study Group criteria for RLS diagnosis. Results: 1,022 pregnant women living in a French town were included. 24% of women were affected by RLS during their pregnancy. The disease was strongly related to the third trimester of pregnancy and had a significant impact on sleep leading to severe nocturnal and diurnal consequences with a high consumption of sleep medication. Conclusions: RLS affects one quarter of pregnant women, essentially during the third trimester and represents an important public health issue with sleep medication intake.
The Effect of PACAP38 on MyD88-Mediated Signal Transduction in Ischemia-/Hypoxia-Induced Acute Kidney Injury
Authors: Li Min , Khan Altaf-M. , Maderdrut Jerome L. , Simon Eric E. , Batuman Vecihi
Published: October 2010

Background/Aims: Toll-like receptor 4 (TLR4) and its adaptor protein MyD88 play an important role in ischemia/reperfusion (I/R) injury in the kidney, and pituitary adenylate cyclase-activating polypeptide (PACAP) could ameliorate renal I/R injury. Methods: Primary cultures of proximal tubule epithelial cells (PTEC) were prepared from wild-type and MyD88–/– mice, and subjected to hypoxia in vitro. Acute kidney injury (AKI) was induced by I/R in vivo in wild-type mice only. Results: Hypoxia resulted in significant increases in cytokine production and apoptosis/necrosis in wild-type PTEC, but these responses were markedly blunted in MyD88–/– PTEC. Treatment with PACAP38 before or after hypoxia further suppressed the hypoxia-induced cytokine responses and apoptosis in both MyD88+/+ and MyD88–/– PTEC cultures. PACAP38 significantly inhibited TLR4/MyD88/TRAF6 as well as TRIF and IRF3 expression in mouse kidney and PTEC, and inhibited the secretion and mRNA expression of cytokines in kidneys from mice after I/R, paralleling the cytokine responses in vitro. Moreover, treatment with PACAP38 protected mice from renal failure, histological damage, neutrophil influx and tubule cell apoptosis after I/R. Conclusion: Our data reveal that the TLR4-mediated cytokine responses to hypoxia are primarily dependent on MyD88 signaling and highlight the pivotal role of MyD88-dependent mechanisms in the coordination of the innate immune responses to ischemic/hypoxic acute renal tubular injury. The renoprotective effect of PACAP in AKI involves both MyD88-dependent and -independent pathways.
Circulating Levels of Allopregnanolone, a Neuroactive Steroid, and Leptin during Treatment with Valproic Acid in Children with Epilepsy
Authors: Grosso Salvatore , Luisi Stefano , Mostardini Rosa , Matera Mariarosaria , Barlocco Enzo Gabriele , Casarosa Elena , Balestri Paolo , Petraglia Felice
Published: October 2010

Weight gain is a well-known unwanted effect of valproic acid (VPA) therapy. Studies on VPA-associated changes of homeostatic hormones remain limited and controversial. Allopregnanolone (AP) is a circulating neuroactive steroid involved in modulation of behavioral activities whose serum levels are increased in obese children. The aim of the present study was to determine whether VPA therapy affects leptin and AP circulating levels in prepubertal girls with epilepsy. One-hundred and one patients were divided into four groups: epileptic patients with VPA-associated obesity (n = 21); lean epileptic patients under VPA therapy (n = 35); healthy obese children (n = 23), and healthy lean children (n = 22). Patients with VPA-associated obesity had significantly enhanced blood concentrations of AP (p = 0.001) and leptin (p = 0.007) than lean subjects. There were no differences in leptin and AP plasma levels between patients with VPA-associated obesity and obese controls (p = 0.45 and p = 0.10, respectively), as there were no differences between lean patients under VPA therapy and lean healthy controls (p = 0.06). In patients under VPA therapy, both plasma leptin and AP levels were significantly correlated with BMI (r = 0.074, p = 0.02, and r = 0.084, p = 0.01, respectively). Plasma leptin concentrations were not correlated with AP levels (r = 0.023, p = 0.13). In conclusion, a correlation between obesity and neuroactive steroids was shown. It remains to be established whether the increased circulating level of AP is a secondary effect of anxiolytic-sedative processes occurring in subjects with obesity-related emotional and behavioral anomalies, or plays a central role in determining abnormal eating behaviors.
Estrogen Receptors and Signaling Pathways in Lactotropes and Somatotropes
Authors: Zárate Sandra , Seilicovich Adriana
Published: October 2010

Estrogens are crucial determinants in the regulation of anterior pituitary function and maintenance of tissue homeostasis. Estrogen actions in this gland are exerted through both classical and non-classical mechanisms of action. This review summarizes the expression of classical α- and β-estrogen receptors and variant isoforms of estrogen receptors in anterior pituitary cell subpopulations. We also analyze estrogen receptor signaling pathways involved in estrogenic actions in the anterior pituitary gland, especially in lactotropes and somatotropes. Complex interactions between multiple signaling pathways are involved in estrogen regulation of hormone secretion, cell proliferation and cell death in this gland. Insight into these pituitary responses to estrogens would help to understand pituitary function and tumorigenesis.
Differential Responses to Emotional Interference in Paranoid Schizophrenia and Bipolar Mania
Authors: Besnier Nathalie , Kaladjian Arthur , Mazzola-Pomietto Pascale , Adida Marc , Fakra Eric , Jeanningros Régine , Azorin Jean-Michel
Published: October 2010

Background: Studies on emotional biases towards threat-related stimuli in schizophrenia and bipolar disorder have provided, so far, inconsistent results. The aim of the present study was to investigate emotional interference in acute schizophrenic and manic patients and its clinical correlates by using a card version of the Emotional Stroop Task designed with neutral, paranoid, depressive and manic words. Methods: Thirty paranoid schizophrenia patients, 30 manic patients and 60 healthy controls were compared on the Emotional Stroop Test. Response times (RT) were collected for each card. Interference indices were calculated by subtracting the RT for the neutral card from the RT for the depressive, paranoid and manic cards. Results: The schizophrenic and manic patient groups showed an increased interference effect when the emotional valence was relating to the disorder-specific psychopathology. In addition, the paranoid interference index correlated with positive symptoms in schizophrenic patients. By contrast, no correlation was evidenced between interference indices and mood symptoms in the manic group. Conclusions: Among schizophrenic patients, paranoid interference might be a state-related emotional abnormality associated with persecutory delusions. In mania, we suggest that emotional biases towards depressive as well as manic information might be trait features of the emotional hyperreactivity involved in the vulnerability to bipolar disorder.
Laboratory Review: The Role of Gait Analysis in Seniors’ Mobility and Fall Prevention
Authors: Bridenbaugh Stephanie A. , Kressig Reto W.
Published: October 2010

Walking is a complex motor task generally performed automatically by healthy adults. Yet, by the elderly, walking is often no longer performed automatically. Older adults require more attention for motor control while walking than younger adults. Falls, often with serious consequences, can be the result. Gait impairments are one of the biggest risk factors for falls. Several studies have identified changes in certain gait parameters as independent predictors of fall risk. Such gait changes are often too discrete to be detected by clinical observation alone. At the Basel Mobility Center, we employ the GAITRite electronic walkway system for spatial-temporal gait analysis. Although we have a large range of indications for gait analyses and several areas of clinical research, our focus is on the association between gait and cognition. Gait analysis with walking as a single-task condition alone is often insufficient to reveal underlying gait disorders present during normal, everyday activities. We use a dual-task paradigm, walking while simultaneously performing a second cognitive task, to assess the effects of divided attention on motor performance and gait control. Objective quantification of such clinically relevant gait changes is necessary to determine fall risk. Early detection of gait disorders and fall risk permits early intervention and, in the best-case scenario, fall prevention. We and others have shown that rhythmic movement training such as Jaques-Dalcroze eurhythmics, tai chi and social dancing can improve gait regularity and automaticity, thus increasing gait safety and reducing fall risk.
Age-Related Effects on Postural Control under Multi-Task Conditions
Authors: Granacher Urs , Bridenbaugh Stephanie A. , Muehlbauer Thomas , Wehrle Anja , Kressig Reto W.
Published: October 2010

Background: Changes in postural sway and gait patterns due to simultaneously performed cognitive (CI) and/or motor interference (MI) tasks have previously been reported and are associated with an increased risk of falling in older adults. Objective: The objectives of this study were to investigate the effects of a CI and/or MI task on static and dynamic postural control in young and elderly subjects, and to find out whether there is an association between measures of static and dynamic postural control while concurrently performing the CI and/or MI task. Methods: A total of 36 healthy young (n = 18; age: 22.3 ± 3.0 years; BMI: 21.0 ± 1.6 kg/m2) and elderly adults (n = 18; age: 73.5 ± 5.5 years; BMI: 24.2 ± 2.9 kg/m2) participated in this study. Static postural control was measured during bipedal stance, and dynamic postural control was obtained while walking on an instrumented walkway. Results: Irrespective of the task condition, i.e. single-task or multiple tasks, elderly participants showed larger center-of-pressure displacements and greater stride-to-stride variability than younger participants. Associations between measures of static and dynamic postural control were found only under the single-task condition in the elderly. Conclusion: Age-related deficits in the postural control system seem to be primarily responsible for the observed results. The weak correlations detected between static and dynamic measures could indicate that fall-risk assessment should incorporate dynamic measures under multi-task conditions, and that skills like erect standing and walking are independent of each other and may have to be trained complementarily.
The Interplay between Cognitive and Motor Functioning in Healthy Older Adults: Findings from Dual-Task Studies and Suggestions for Intervention
Authors: Schaefer Sabine , Schumacher Vera
Published: October 2010

Reaching late adulthood is accompanied by losses in physical and mental resources, but lifestyle choices seem to have a considerable influence on the aging trajectory. This review deals with the interplay between cognitive and motor functioning in old age, focusing on two different lines of research, namely (a) dual-task studies requiring participants to perform a cognitive and a motor task simultaneously, and (b) intervention studies investigating whether increases in physical fitness also lead to improvements in cognitive performance. Dual-task studies indicate that healthy older adults show greater performance reductions in both domains than young adults when performing a cognitive and a motor task simultaneously. In addition, older adults often tend to protect their motor functioning at the expense of the cognitive task when the situation involves a threat to balance. This can be considered an adaptive behavior since fall-related injuries can have severe consequences. Fitness intervention studies which increased the aerobic fitness of previously sedentary older adults have demonstrated impressive performance improvements in the cognitive domain, especially for tasks involving executive control processes. These findings are interesting in light of cognitive intervention studies, which often fail to find significant transfer effects to tasks that have not been trained directly. The authors argue that future research should compare the effects of cognitive and aerobic fitness interventions in older adults, and they present a study design in which cognition and fitness are trained sequentially as well as simultaneously. Finally, methodological issues involved in this type of research and potential applications to applied settings are discussed.
Rationale for Combined Exercise and Cognition-Focused Interventions to Improve Functional Independence in People with Dementia
Authors: Thom Jeanette M. , Clare Linda
Published: October 2010

Evidence suggests that exercise and some cognition-focused intervention approaches can be used to elicit functional improvements in older people and, to some degree, those diagnosed with dementia. Independently, the two intervention types have been found to improve functional performance in people with dementia. The mechanisms underpinning these improvements come from comparable and diverse pathways. This suggests that it may be beneficial for the two intervention types to be coupled as part of regular care in individuals with a range of cognitive impairments. The aims of this review are threefold. The first aim is to present evidence to support the use for combining exercise and cognition-focused interventions. This will be achieved by reviewing the mechanisms of both approaches in improving functional performance in older people and in people with dementia and summarising recent progress. The increased risk of depression, falls and cardiovascular disease risk in people with dementia will also be highlighted. The second aim is to discuss the parameters of the two approaches that should be considered when combining them in terms of possible efficient models, especially in relation to exercise protocols as this is where the current literature shows the most promising outcomes. Maximisation of the efficacy of preventative and treatment interventions which focus on both cognitive functioning and physical health should lead to improving and extending functional independence. Key aspects of any combined intervention would involve the inclusion of both cardiovascular and other types of exercises, including falls reduction, and exercises addressing memory and executive function via goal setting in the real-life context. The third aim is to explore some of the issues that may arise when attempting to incorporate interventions into the regular treatment of people with dementia. Consideration must also be given to caregivers and the education of health professionals as well as to the mode of intervention itself. Further research is necessary in order to discern the most effective types of both intervention models. Provision of combined interventions might enhance the improvements in functional independence in people with dementia over and above the interventions being used separately.
Oxidative Stress and Diabetic Complications
Authors: Giacco Ferdinando , Brownlee Michael
Published: October 2010

Oxidative stress plays a pivotal role in the development of diabetes complications, both microvascular and cardiovascular. The metabolic abnormalities of diabetes cause mitochondrial superoxide overproduction in endothelial cells of both large and small vessels, as well as in the myocardium. This increased superoxide production causes the activation of 5 major pathways involved in the pathogenesis of complications: polyol pathway flux, increased formation of AGEs (advanced glycation end products), increased expression of the receptor for AGEs and its activating ligands, activation of protein kinase C isoforms, and overactivity of the hexosamine pathway. It also directly inactivates 2 critical antiatherosclerotic enzymes, endothelial nitric oxide synthase and prostacyclin synthase. Through these pathways, increased intracellular reactive oxygen species (ROS) cause defective angiogenesis in response to ischemia, activate a number of proinflammatory pathways, and cause long-lasting epigenetic changes that drive persistent expression of proinflammatory genes after glycemia is normalized (“hyperglycemic memory”). Atherosclerosis and cardiomyopathy in type 2 diabetes are caused in part by pathway-selective insulin resistance, which increases mitochondrial ROS production from free fatty acids and by inactivation of antiatherosclerosis enzymes by ROS. Overexpression of superoxide dismutase in transgenic diabetic mice prevents diabetic retinopathy, nephropathy, and cardiomyopathy. The aim of this review is to highlight advances in understanding the role of metabolite-generated ROS in the development of diabetic complications.
Microparticles
Authors: Mause Sebastian F. , Weber Christian
Published: October 2010

Microparticles represent a heterogeneous population of vesicles with a diameter of 100 to 1000 nm that are released by budding of the plasma membrane and express antigens specific of their parental cells. Although microparticle formation represents a physiological phenomenon, a multitude of pathologies are associated with a considerable increase in circulating microparticles, including inflammatory and autoimmune diseases, atherosclerosis, and malignancies. Microparticles display an broad spectrum of bioactive substances and receptors on their surface and harbor a concentrated set of cytokines, signaling proteins, mRNA, and microRNA. Recent studies provided evidence for the concept of microparticles as veritable vectors for the intercellular exchange of biological signals and information. Indeed, microparticles may transfer part of their components and content to selected target cells, thus mediating cell activation, phenotypic modification, and reprogramming of cell function. Because microparticles readily circulate in the vasculature, they may serve as shuttle modules and signaling transducers not only in their local environment but also at remarkable distance from their site of origin. Altogether, this transcellular delivery system may extend the confines of the limited transcriptome and proteome of recipient cells and establishes a communication network in which specific properties and information among cells can be efficiently shared. At least in same cases, the sequential steps of the transfer process underlie complex regulatory mechanisms, including selective sorting (“packaging”) of microparticle components and content, specificity of interactions with target cells determined by surface receptors, and ultimately finely tuned and signal-dependent release and delivery of microparticle content.
Voting for Our Story: A Narrative Model of Electoral Choice in Multiparty Systems
Authors: Sheafer Tamir , Shenhav Shaul R. , Goldstein Kenneth
Published: October 2010

Based on narrative approaches, the authors develop an empirical technique to gauge the match between stories told by political actors and voters and assess its effect on voting behavior. Even with other fundamental attitudinal and demographic factors held constant, they hypothesize that voters should prefer parties that hold and communicate similar national narratives. Using data gathered during the 2009 elections to the Israeli Knesset, the authors gauge voter attitudes about fundamental national narratives in Israel and conduct a systematic analysis of parties’ discourse in parliamentary speeches to gauge parties’ stories. Controlling for demographics and ideology in a series of logistic regressions, the authors find that voting behavior for most parties is significantly affected by the narrative proximity between voters’ stories and parties’ stories.
Australian dental students views on a compulsory internship scheme
Authors: Lalloo Ratilal , Johnson Newell W , Blinkhorn Anthony S , Ichim Paul
Published: October 2010

Objective: The National Health and Hospitals Reform Commission Report suggests introducing an internship period for all newly qualified dental/oral health practitioners in Australia. This study gauged the opinions of undergraduates from three dental schools in Australia.

Methods: An online survey collected demographic information on gender and age, the program registered for, year and place of study. The level of support for an internship was gauged using a five-point scale. Open-ended questions on the concerns, advantages and disadvantages of an internship concluded the survey. All students in the participating universities were invited to participate via email.

Results: There were 445 responses. Forty per cent of students were supportive of an internship scheme. The level of support differed by gender, age, relationship status, having a previous tertiary qualification and year of study. Males, older participants, those with children and those with previous qualifications were less supportive. The main concerns related to issues around choice, family commitments, location of internship placements and salary levels.

Conclusion: Support for an internship scheme for dental graduates elicited a divided opinion amongst dental students. Many issues around financing and logistics have to be addressed before any such scheme could be implemented in Australia: there is a need to consult with dental graduates and promote the benefits to the student body.
Role of Powder in the Machining of Al-10%Sicp Metal Matrix Composites by Powder Mixed Electric Discharge Machining
Authors: Kumar Harmesh , Davim J. Paulo
Published: October 2010

This article reports the results of an experimental study conducted with the objective to understand the mechanism of material removal (role of silicon powder) in powder mixed electric discharge machining (PMEDM) while machining the Al-10%SiCP metal matrix composites. PMEDM is relatively a new development in the direction of enhancement of process capabilities of EDM. A new experimental set-up has been developed in the laboratory for experimentation. This research points out how the suspended powder helps in improving the performance of EDM. Further, the effect of the suspended powder and other selected parameters on process performance (machining rate (MR) and surface roughness (SR)) and subsequent optimal settings of the variables have been obtained using Taguchi method. The obtained experimental results indicate significantly improved performance of PMEDM over EDM. The appropriate addition of silicon powder into the dielectric fluid of EDM increases the MR and decreases the SR. The experimental results further indicate that the powder concentration, peak current, and pulse duration are the significant variables, while the supply voltage is an insignificant variable. The results were verified by conducting confirmation experiments with optimal process conditions.
Effect of polypropylene molecular weight, hydroxyapatite particle size, and Ringer’s solution on creep and impact behavior of polypropylene-surface treated hydroxyapatite biocomposites
Authors: Younesi M. , Bahrololoom M.E.
Published: October 2010

In this study, bovine bone was burnt at 400°C and the resulting ash was heat-treated at 900°C for 90 min to get a white powder. Chemical analysis showed that this white powder was mainly hydroxyapatite (HA). Three different average particle sizes of this powder were produced by milling at three different times. The produced HA was surface treated with a silane coupling agent. Composite samples with 40 vol.% of HA were produced by hot press molding and so mechanical testing was done on the specimens in air and Ringer’s solution. The results of these tests showed that on increasing the molecular weight of polypropylene (PP), creep strain of composites decreases proportionally, and ultimate tensile strength (UTS) and impact resistance increase dramatically. In addition, result of mechanical tests on the soaking specimens in Ringer’s solution showed that Ringer’s solution intensively decreases UTS, creep, and impact properties of PP—HA composite. Furthermore, decreasing HA particle size caused UTS rise, creep strain fall, and impact resistance rise for composites in air condition. Vice versa, in wet condition, decreasing HA particle size caused UTS, creep, and impact resistance to fall. Fracture surfaces of impact samples tests were analyzed by a scanning electron microscope.
Bending analysis of stiffened composite conoidal shell roofs through finite element application
Authors: Hari Sadhan Das  , Chakravorty Dipankar
Published: October 2010

This article applies a combination of an eight-noded shell element with a three-noded beam element to solve a bending problem of a composite stiffened conoidal shell subjected to a concentrated load at the center. Benchmark problems are solved for validation of the present approach and a wide spectrum of stiffened conoidal shell problems are solved for various parametric variation of shell surfaces and positions of stiffeners. Both static deflections and force/moment resultants are examined thoroughly. The performances of the different shell options are studied by arranging them rankwise and through a typical relative performance matrix.
Composite materials obtained from textile fiber residue
Authors: Mulinari D.R. , Voorwald H.J.C. , Cioffi M.O.H. , Lima C.A.A. , Baptista C.A.P.R. , Rocha G.J.M.
Published: October 2010

This article presents the use of fibers residue from textile industry to minimize environmental problems associated with material accumulation. Composite materials utilizing textile fiber residues and high density polyethylene were prepared. Effect of treatment with hot water on fibers to prepare composites was studied to provide an improvement in mechanical properties of these materials. This treatment on fibers was evaluated by X-ray diffraction and scanning electron microscopy techniques. Experimental results of mechanical properties indicated higher mechanical strength for treated fiber composites compared to the untreated fiber composites.
Fabrication and mechanical properties of UV-curable glass fiber-reinforced polymer—matrix composite
Authors: Yugang Duan  , Yanjun Wang  , Yiping Tang  , Dichen Li  , Bingheng Lu
Published: October 2010

A UV-curable glass fiber-reinforced composites was investigated in order to develop a cost-effective fabrication approach for manufacturing polymer—matrix composites. The effects of glass fiber-treating process and UV exposure power on the tensile strength were studied through scanning electron microscopy, contact angle determination, and curing degree test. The experimental results showed 11.5% increase in tensile strength for the UV-cured composite reinforced with heat-treated glass fiber, and 51.4% increase with glass fiber treated by coupling agent. The optimal exposure power was 0.94 J/mm2 to obtain the optimized mechanical properties. However, overexposure could seriously result in the loss of tensile strength. The maximum tensile strength and shear strength of composite cured by UV approach in this study were 902.09 and 25.04 MPa, respectively.
Eco-composite: the effects of the jute fiber treatments on the mechanical and environmental performance of the composite materials
Authors: Alves C. , Dias A.P.S. , Diogo A.C. , Ferrão P.M.C. , Luz S.M. , Silva A.J. , Reis L. , Freitas M.
Published: October 2010

In this study, untreated and treated jute fiber composites were investigated as candidates to replace glass fibers as reinforcement to produce structural composites with better environmental performance. The surface of the jute fibers was modified by drying and bleaching/drying treatments to improve the wetting behavior of the apolar polyester, improving the mechanical properties of the composites. The mechanical characterization of the composites was obtained according to the ASTM standards (D-3039/D-790) and dynamic mechanical analysis. The environmental characterization was obtained by life-cycle assessment method. The treatment characterization was obtained by horizontal attenuated total reflectance infrared spectroscopy and thermogravimetry. Finally, jute composites were compared with glass composites and results show that the jute fiber treatments imply a significant increase of the mechanical properties of the composites without damaging their environmental performances.
A study on the fracture morphology of brittle fibers under different strain rates
Authors: Wen Huang  , Zhongwei Huang
Published: October 2010

Three kinds of brittle fibers (SiC fiber, glass fiber, and carbon fiber) were tensioned to fracture at both quasi-static and dynamic loading rates. Scanning electron microscope observations of the morphology of the fracture surfaces show two distinct fracture modes for all three fibers. The mode of fracture changes with the loading rate, in a way that correlates with the stain-rate dependence of the fiber strength. Based on this observation, we explore the effects of fracture mode on the strength of brittle fibers, and discuss the pertinence of this observation to classical fiber strength theories, including the ‘weakest link’ principle and the Weibull strength distribution theory.
Effects of weathering on failure pressure of filament-wound GFRP thermoset pipes
Authors: Al-Sulaiman F. , Khan Z. , Merah N. , Kounain M.A. , Mehdi M.
Published: October 2010

Burst tests have been performed on the glass fiber-reinforced (GFR) thermoset pipes before and after exposure to natural and accelerated environmental conditions. The main objective of this study was to explore the effects of long-term natural outdoor and artificial accelerated environmental conditions on the burst resistance of the vinyl-based and epoxy-based GFR filament wound thermoset pipes which are targeted for use in crude oil transportation. The pipes were exposed to natural outdoor and accelerated dry heat conditions. The results show that these environments did not produce any noticeable degradation in the hydrostatic burst resistance of the pipes up to 24 months of natural exposure and up to 10,000 h of dry heat exposure.