bluuebunny/crossref_metadata_2025_split huggingface dataset:
Force spectroscopy of an elastic peptide: Effect of D2O and temperature on persistence length
Authors: Haward Simon J. , Shewry Peter R. , Marsh Justin , Miles Mervyn J. , Mc Master Terence J. 
Published: June 2010

AbstractThis study explores the mechanical unfolding of elastic protein analogues as a function of temperature, in both H2O and D2O, using atomic force microscopy (AFM) force spectroscopy in a specially constructed AFM liquid cell. This represents the first time that the effect of D2O on protein flexibility has been investigated at the single molecule level by this technique. Model elastic peptides, R6, were encoded from synthetic genes expressed in Escherichia coli. The peptides possess short N‐ and C‐terminal domains with central repetitive domains containing 13 repeats of the motif PGQGQQ‐plus‐GYYPTSLQQ. These sequences mimic those in native high molecular weight subunit glutenin proteins which confer elasticity to bread dough. Fitting single molecule stretching events to the worm‐like chain model, allows determination of the molecular persistence length under various experimental conditions. The effect of increasing the temperature is to increase the persistence length of the peptide in both H2O and D2O, consistent with the expected “thermal softening” effect. However, the effect is significantly enhanced in D2O, in which the persistence length at 45°C is ∼25% greater than the value measured in H2O at the same temperature. Stronger intrapeptide H‐bonding due to isotopic substitution of hydrogen for deuterium is the most likely cause of the enhanced backbone rigidity. Microsc. Res. Tech. 74:170–176, 2011. © 2010 Wiley‐Liss, Inc.
Effects of ethanol, formaldehyde, and gentle heat fixation in confocal resonance Raman microscopy of purple nonsulfur bacteria
Authors: Kniggendorf Ann‐Kathrin , Gaul Tobias William , Meinhardt‐Wollweber Merve 
Published: June 2010

AbstractResonance Raman microscopy is well suited to examine living bacterial samples without further preparation. Therefore, comparatively little thought has been given to its compatibility with common fixation methods. However, fixation of cell samples is a very important tool in the microbiological sciences, allowing the preservation of samples in a specific condition for further examination, future measurements, transport, or later reference. We examined the effects of three common fixatives—ethanol, formaldehyde solution, and gentle heat—on the resonant Raman spectrum of three generic bacteria species, Rhodobacter sphaeroides DSM 158T, Rhodopseudomonas palustris DSM 123T, and Rhodospirillum rubrum DSM 467T, holding carotenoid‐ and heme‐chromophores in confocal Raman microscopy. In addition, we analyzed the effect of poly‐L‐lysine coating of microscope slides, widely used for mounting biological and medical samples, on subsequent confocal Raman measurements of native and fixed samples. The results indicate that ethanol is preferable to formaldehyde as fixative if applied for less than 24 h, whereas heat fixation has a strong, detrimental effect on the resonant Raman spectrum of bacteria. Formaldehyde fixation excels at fixation times above 24 h, but causes an overall reduction in signal intensity. Poly‐L‐lysine coating has no discernable effect on the Raman spectra of samples fixed with ethanol or heat, but it further decreases the signal intensity, especially at higher wavenumbers, in the spectra of samples fixed with formaldehyde. Microsc. Res. Tech. 74:177–183, 2011. © 2010 Wiley‐Liss, Inc.
Tandem mass spectrometry for the analysis of self‐sorted pseudorotaxanes: the effects of Coulomb interactions
Authors: Jiang Wei , Schalley Christoph A. 
Published: June 2010

AbstractThe increasing complexity of self‐assembled supramolecules generates the need for analytical techniques that can accurately elucidate their structures. Here, we explore the ability of tandem mass spectrometry to deliver structural information on a series of self‐sorted crown ether/ammonium pseudorotaxanes. Of these intertwined molecules, different charge states are accessible and the effects of Coulomb interactions on the fragmentation pattern can be examined. Three different cases can be distinguished: (1) one or more counterions are present in the complex and compete with the crown for binding to the ammonium ion. This destabilizes the supramolecular bond. (2) In multiply charged complexes, charge repulsion significantly alters the fragmentation behavior as compared with singly charged ions. (3) If guest and host are both charged, the supramolecular bond becomes very weak. The different charge states provide different pieces of information about the supramolecules under study. Although singly charged complexes provide data on the building block connectivity, the doubly charged analogs are more reliable with respect to complex stoichiometry. As there are several factors which may cause differences in the gas phase and solution behavior of supramolecules (the presence and absence of solvation, changes in the strength of non‐covalent interactions upon ionization), it is important to establish well understood correlations between the complexes' gas‐phase behavior and their solution structures. A more detailed understanding will help to characterize the structures of even more complex supramolecular architectures by mass spectrometry. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical inducers and transcriptional markers of oligodendrocyte differentiation
Authors: Joubert Lara , Foucault Isabelle , Sagot Yves , Bernasconi Lilia , Duval François , Alliod Chantal , Frossard Marie‐José , Pescini Gobert Rosanna , Curchod Marie‐Laure , Salvat Catherine , Nichols Anthony , Pouly Sandrine , Rommel Christian , Roach Arthur , Hooft van Huijsduijnen Rob 
Published: June 2010

AbstractOligodendrocytes generate and maintain myelin, which is essential for axonal function and protection of the mammalian central nervous system. To advance our molecular understanding of differentiation by these cells, we screened libraries of pharmacologically active compounds and identified inducers of differentiation of Oli‐neu, a stable cell line of mouse oligodendrocyte precursors (OPCs). We identified four broad classes of inducers, namely, forskolin/cAMP (protein kinase A activators), steroids (glucocorticoids and retinoic acid), ErbB2 inhibitors, and nucleoside analogs, and confirmed the activity of these compounds on rat primary oligodendrocyte precursors and mixed cortical cultures. We also analyzed transcriptional responses in the chemically induced mouse and rat OPC differentiation processes and compared these with earlier studies. We confirm the view that ErbB2 is a natural signaling component that is required for OPC proliferation, whereas ErbB2 inhibition or genetic knockdown results in OPC differentiation. © 2010 Wiley‐Liss, Inc.
Chronic caloric restriction reduces tissue damage and improves spatial memory in a rat model of traumatic brain injury
Authors: Rich Nicholas J. , Van Landingham Jacob W. , Figueiroa Silvia , Seth Rohit , Corniola Rikki S. , Levenson Cathy W. 
Published: June 2010

AbstractAlthough it has been known for some time that chronic caloric or dietary restriction reduces the risk of neurodegenerative disorders and injury following ischemia, the possible role of chronic restriction in improving outcomes after traumatic brain injury (TBI) has not been previously studied. Therefore, 2‐month‐old male Sprague‐Dawley rats were divided into two dietary groups, an ad libitum fed group (AL) and a caloric‐restriction group (CR) that was provided with 70% of the food intake of AL rats (n = 10/group). After 4 months, a weight‐drop device (300 g) was used to produce a 2‐mm bilateral medial frontal cortex contusion following craniotomy. Additional animals in each dietary group (n = 10) were used as sham‐operated controls. The CR diet resulted in body weights that were reduced by 30% compared with AL controls. Not only did CR decrease the size of the cortical lesion after injury, there were marked improvements in spatial memory as measured by Morris water maze that included an increase in the number of animals successfully finding the platform as well as significantly reduced time to finding the hidden platform. Western analysis, used to examine the expression of proteins that play a role in neuronal survival, revealed significant increases in brain‐derived neurotrophic factor (BDNF) in the cortical region around the site of injury and in the hippocampus in CR rats after injury. These findings suggest that molecular mechanisms involved in cell survival may play a role in reducing tissue damage and improving cognition after TBI and that these mechanisms can be regulated by dietary interventions. © 2010 Wiley‐Liss, Inc.
Amyloid‐β oligomers impair fear conditioned memory in a calcineurin‐dependent fashion in mice
Authors: Dineley Kelly T. , Kayed Rakez , Neugebauer Volker , Fu Yu , Zhang Wenru , Reese Lindsay C. , Taglialatela Giulio 
Published: June 2010

AbstractSoluble oligomeric aggregates of the amyloid‐β (Aβ) peptide are believed to be the most neurotoxic Aβ species affecting the brain in Alzheimer disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underscored by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that Aβ oligomers are recruited at the synapse, oppose expression of long‐term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines, and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of Aβ‐mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in these pathological processes of AD. CaN is especially abundant in the CNS, where it is involved in synaptic activity, LTP, and memory function. Here, we describe how oligomeric Aβ treatment causes memory deficits and depresses LTP expression in a CaN‐dependent fashion. Mice given a single intracerebroventricular injection of Aβ oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by Aβ oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disruption induced by acute oligomeric Aβ treatment in mice. © 2010 Wiley‐Liss, Inc.
Effects of zona incerta lesions on striatal neurochemistry and behavioral asymmetry in 6‐hydroxydopamine‐lesioned rats
Authors: Walker Ruth H. , Davies Georgia , Koch Rick J. , Haack Andrew K. , Moore Cynthia , Meshul Charles K. 
Published: June 2010

AbstractAnalysis of optimal sites for neurosurgical interventions in patients with Parkinson's disease (PD) suggests that significant clinical benefits may be achieved by involvement of the zona incerta (ZI). Unilateral electrolytic ZI lesions were made in intact and ipsilaterally 6‐hydroxydopamine (6OHDA)‐lesioned rats. Extracellular levels of glutamate, dopamine, and its metabolites in the ipsilateral striatum of awake rats were measured by using microdialysis, and tests of behavioral asymmetry were performed. In intact rats, ZI lesions had no effect on striatal extracellular glutamate or absolute levels of dopamine or metabolites, but dopamine metabolism decreased. After ZI lesions, contralateral forepaw use decreased in the forepaw adjusting steps test, but there was no change in response to vibrissa stimulation or cylinder exploration. There was no development of rotational asymmetry with amphetamine. In 6OHDA‐lesioned rats, striatal extracellular glutamate levels were elevated compared with controls. ZI lesions reduced the increased levels of glutamate back to normal values. ZI lesions reduced dopamine and homovanillic acid levels and showed a trend toward a decrease in dopamine metabolism. 6OHDA‐lesioned rats demonstrated the expected asymmetry of motor behaviors. After ZI lesions, ipsilateral turns following amphetamine injection were reduced, and there was a trend toward improved symmetry of forepaw use as determined with the forepaw adjusting steps test. There was no change in forepaw use with vibrissa stimulation or cylinder exploration. These data indicate that lesions of the ZI can affect striatal neurochemistry and motor behavioral asymmetry and suggest potential mechanisms by which ZI lesions may improve symptoms in PD. © 2010 Wiley‐Liss, Inc.
Low‐temperature Raman spectroscopic studies in NaNbO3
Authors: Mishra K. K. , Sivasubramanian V. , Arora A. K. 
Published: June 2010

AbstractRaman spectroscopic measurements were carried out in the temperature range 10–300 K to understand the low‐temperature antiferroelectric (AFE)–ferroelectric (FE) phase transition in NaNbO3. Several modes in the low wavenumber range were found to disappear, while some new modes appeared across the transition. The temperature dependence of mode wavenumbers suggests that, during cooling, the AFE–FE phase transition begins to occur at 180 K, while the reverse transition starts at 260 K during heating. During cooling, the two phases were found to coexist in the temperature range of 220–160 K. Upon heating, the FE phase is retained up to 240 K and both FE and AFE phases coexist in the temperature range 240–300 K. In contrast to the earlier reports, the present results suggest a different coexistence region and the reverse transition temperature. The reported relaxor‐type FE behaviour over a broad temperature is consistent with the observed coexistence of phases during cooling and heating cycles. Copyright © 2010 John Wiley & Sons, Ltd.
Safety of sentinel node biopsy in breast cancer patients who receive a second radioisotope injection after visualization failure in lymphoscintigraphy
Authors: Meretoja Tuomo J. , Joensuu Heikki , Heikkilä Päivi S. , Leidenius Marjut H. 
Published: June 2010

AbstractBackground and ObjectivesA failure to visualize axillary sentinel nodes in lymphoscintigraphy may lead to an unsuccessful sentinel node biopsy (SNB) and subsequent axillary lymph node dissection (ALND). To avoid unnecessary ALND, a second radioisotope injection may be given but has been considered hazardous. We investigated the axillary recurrence rate after tumor‐negative SNB in breast cancer patients who received a second tracer injection after axillary visualization failure in lymphoscintigraphy.MethodsAltogether 1,309 breast cancer patients who underwent a tumor‐negative SNB without an ALND were included. Two hundred seven (15.8%) patients received a second tracer injection due to visualization failure in lymphoscintigraphy and 1,102 (84.2%) did not. All patients received a blue dye injection prior to the SNB. The median follow‐up time was 43 months.ResultsNo isolated cancer recurrences were diagnosed in the ipsilateral axilla among patients who received two radioisotope injections. Disease‐free survival and overall survival were similar among patients with one or two radioisotope injections (P = 0.122 and P = 0.200, respectively).ConclusionsAdditional radiocolloid tracer injection after axillary non‐visualization in lymphoscintigraphy is safe and does not increase axillary recurrence risk after tumor‐negative SNB. The results suggest that such patients can be safely managed with SNB without a need to perform an ALND. J. Surg. Oncol. 2010;102:649–655. © 2010 Wiley‐Liss, Inc.
Deep brain stimulation in the posterior subthalamic area in the treatment of essential tremor
Authors: Blomstedt Patric , Sandvik Ulrika , Tisch Stephen 
Published: June 2010

AbstractTo evaluate the posterior subthalamic area (PSA) as a target for deep brain stimulation (DBS) in the treatment of essential tremor (ET). The ventral intermediate nucleus of the thalamus is the traditional target for DBS in the treatment of ET. Recent studies have presented beneficial effects of DBS in the PSA in the treatment of tremor. Twenty‐one patients with ET were included in this study. All patients were evaluated before and 1 year after surgery, on and off stimulation, using the essential tremor rating scale (ETRS). A marked microlesional effect was noticed in 83%, in some cases obviating the need for electrical stimulation for many months. The total ETRS was reduced from 46.2 at baseline to 18.7 (60%). Item 5/6 (tremor of the upper extremity) was improved from 6.2 to 0.3 (95%), and items 11 to 14 (hand function) from 9.7 to 1.3 (87%) concerning the contralateral hand. Activities of daily living were improved by 66%. No severe complication occurred. Eight patients presented a postoperative mild dysphasia that regressed within days to weeks. DBS in the PSA resulted in a marked reduction of tremor. © 2010 Movement Disorder Society
Benign hereditary chorea: Clinical and neuroimaging features in an Italian family
Authors: Salvatore Elena , Di Maio Luigi , Filla Alessandro , Ferrara Alfonso M. , Rinaldi Carlo , Saccà Francesco , Peluso Silvio , Macchia Paolo E. , Pappatà Sabina , De Michele Giuseppe 
Published: June 2010

AbstractBenign hereditary chorea is an autosomal dominant disorder characterized by early onset nonprogressive chorea, caused by mutations of the thyroid transcription factor‐1 (TITF‐1) gene. Clinical heterogeneity has been reported and thyroid and respiratory abnormalities may be present. We describe 3 patients of an Italian family carrying the S145X mutation in the TITF‐1 gene with mild motor delay, childhood onset dyskinesias, and subtle cognitive impairment. A child in the third generation presented with congenital hypothyroidism and neonatal respiratory distress. Imaging studies in 2 patients showed mild ventricular enlargement and empty sella at magnetic resonance imaging and hypometabolism of basal ganglia and cortex at 18‐Fluoro‐2‐deoxy‐glucose positron emission tomography. © 2010 Movement Disorder Society
Transcranial brain sonography in Parkinson's disease with restless legs syndrome
Authors: Kwon Do‐Young , Seo Woo‐Keun , Yoon Ho‐Kyoung , Park Moon‐Ho , Koh Seong‐Beom , Park Kun‐Woo 
Published: June 2010

AbstractSubstantia nigra (SN) hyperechogenicity assessed by transcranial brain sonography (TCS) is a characteristic finding in idiopathic Parkinson's disease (PD). In contrast, SN hypoechogenicity on TCS has been recently demonstrated in restless legs syndrome (RLS). RLS is one of the most common sleep problems in PD, but the pathophysiologic relationship between these two disorders has not been thoroughly elucidated. We compared the SN echogenicities of PD patients with and without RLS to investigate whether comorbid RLS in PD affects SN echogenicity and to explain the echogenic differences between idiopathic RLS (iRLS) and secondary PD–related RLS (pRLS). Sixty‐three PD patients (median age 64.6 ± 10.6 years), 40 iRLS patients (53.1 ± 11.7 years), and 40 healthy controls (69.1 ± 2.3 years) were enrolled in our study. All subjects answered a sleep questionnaire and underwent TCS. PD patients were subdivided into two groups, PD with RLS (PD+RLS, n = 26) and PD without RLS (PD‐RLS, n = 37), and the sonographic findings of each group were compared. Although significant hyperechogenicity was detected in both the SN and SN/midbrain ratios in both PD subgroups compared with the controls and the iRLS group (P < 0.001), there were no significant differences in SN echogenicity between the PD+RLS and PD‐RLS groups. Meanwhile, iRLS patients showed significant SN hypoechogenicity. In conclusion, comorbid RLS in PD did not have an impact on the sonographic SN findings. These results suggest that the pathogenesis of pRLS and iRLS involve different mechanisms. Further study will be required to clarify the association between RLS and PD. © 2010 Movement Disorder Society
Rationale for delayed‐start study of pramipexole in Parkinson's disease: The PROUD study
Authors: Schapira Anthony H.V. , Albrecht Stefan , Barone Paolo , Comella Cynthia L. , McDermott Michael P. , Mizuno Yoshikuni , Poewe Werner , Rascol Olivier , Marek Kenneth 
Published: June 2010

AbstractPerhaps the most important unmet need in Parkinson's disease (PD) is the ability to slow or prevent progression of the neurodegeneration that underlies the motor and nonmotor features of this disorder. Pramipexole, a dopamine agonist used for the symptomatic treatment of PD, has demonstrated neuroprotective properties in laboratory studies. The PRamipexole On Underlying Disease (PROUD) study is a randomized, double‐blind clinical trial evaluating the ability of pramipexole to modify disease progression using a delayed‐start design. PD patients (n = 535) with mean age 62.5 years, mean duration since diagnosis of 4.4 months, and mean total Unified Parkinson's disease Rating Scale (UPDRS) score of 24.5 were recruited. In Phase I, patients were randomly assigned to be titrated to 1.5 mg pramipexole or placebo and maintained on study drug for 6–9 months. In Phase II, all patients were titrated to 1.5 mg pramipexole and maintained on study drug until the end of the study at 15 months. No rescue medication was allowed in the protocol. The primary endpoint is the change in total UPDRS score (parts I–III) from baseline to 15 months. A range of secondary endpoints separately assess UPDRS subscales, quality of life, depression, and impulse control disorders. A sub‐study examined dopamine transporter uptake scans at baseline and 15 months. The results of PROUD will provide insight into the potential for early versus delayed treatment with pramipexole to modify motor outcome at 15 months in recently diagnosed PD patients. © 2010 Movement Disorder Society
The impact of miscarriage and parity on patterns of maternal distress in pregnancy
Authors: Woods‐Giscombé Cheryl L. , Lobel Marci , Crandell Jamie L. 
Published: June 2010

AbstractThe purpose of the current study was to examine patterns of state anxiety and pregnancy‐specific distress across pregnancy in a diverse sample of women with (n = 113) and without (n = 250) prior miscarriage. For both groups, state anxiety and pregnancy‐specific distress were highest in the first trimester and decreased significantly over the course of pregnancy. Compared to women without prior miscarriage, women with prior miscarriage experienced greater state anxiety in the second and third trimesters. Having a living child did not buffer state anxiety in women with a prior miscarriage. Attention to patterns of distress can contribute to delivery of appropriate support resources to women experiencing pregnancy after miscarriage and may help reduce risk for stress‐related outcomes. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:316–328, 2010