bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Determinants of Multiple Sclerosis in Longitunal Studies: A Bayesian Approach
Authors: Di Serio Clelia , Lamina Claudia
Published: December 2009

Modelling data from Multiple Sclerosis longitudinal studies
is a challenging topic since the phenotype of interest is typically ordinal;
time intervals between two consecutive measurements are nonconstant
and they can vary among individuals. Due to these unobservable
sources of heterogeneity statistical models for analysis of Multiple Sclerosis
severity evolve as a difficult feature. A few proposals have been
provided in the biostatistical literature (Heijtan (1991); Albert, (1994)) to
address the issue of investigating Multiple Sclerosis course. In this paper
Bayesian P‐Splines (Brezger and Lang, (2006); Fahrmeir and Lang
(2001)) are indicated as an appropriate tool since they account for nonlinear
smooth effects of covariates on the change in Multiple Sclerosis
disability. By means of Bayesian P‐Spline model we investigate both
the randomness affecting Multiple Sclerosis data as well as the ordinal
nature of the response variable.
Competition between Plasmid‐Bearing and Plasmid‐Free Organisms in a Chemostat with Pulsed Input and Washout
Authors: Yuan Sanling , Zhao Yu , Xiao Anfeng
Published: December 2009

We consider a model of competition between plasmid‐bearing and plasmid‐free organisms in the chemostat with pulsed input and washout. We investigate the subsystem with nutrient and plasmid‐free organism and study the stability of the boundary periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields the invasion threshold of the plasmid‐bearing organism. By using the standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in substrate, plasmid‐free, and plasmid‐bearing organisms. Numerical simulations are carried out to illustrate our results.
Synthesize and Characterization of Hollow Boron‐Nitride Nanocages
Authors: Zhang W. S. , Zheng J. G. , Li W. F. , Geng D. Y. , Zhang Z. D.
Published: December 2009

The boron‐nitride (BN) nanocages are synthesized by nitrogenation of amorphous boron nanoparticles at 1073 K under nitrogen and ammonia atmosphere. The BN nanocages exhibit a well‐crystallized feature with nearly pentagonal or spherical shape, depending on their size. High‐resolution transmission electron microscopy studies reveal that they are hollow nanocages. The growth mechanism of the BN nanocages is proposed.
The Sandblaster Software-Defined Radio Platform for Mobile 4G Wireless Communications
Authors: Surducan V. , Moudgill M. , Nacer G. , Surducan E. , Balzola P. , Glossner J. , Stanley S. , Yu Meng , Iancu D.
Published: December 2009

We present a tier 2 Software Defined-Radio platform (SDR), built around the latest Sandbridge Technologies' multithreaded Digital Signal Processor (DSP) SB3500, along with the description of major design steps taken to ensure the best radio link and computational performance. This SDR platform is capable of executing 4G wireless communication standards such as WiMAX Wave 2, WLAN 802.11 g, and LTE. Performance results for WiMAX are presented in the conclusion section.
Electrochemical Reduction of Uniformly Dispersed Pt and Ag Nanodots on Carbon Fiber Electrodes
Authors: Pai Yi-Hao , Lin Gong-Ru
Published: December 2009

Electrochemical characterization of the uniformly dispersed Pt and Ag nanodots synthesized after in situ scalable electron‐beam reduction on copper grid and carbon‐fiber electrode is demonstrated. By employing plasma pretreatment to produce functional organosilicon micronetworks‐based reaction sites on copper grid, the size and standard deviation of the electrochemically reduced metallic nanodots can be strictly confined. When detuning the accelerating voltage of electron‐beam from 3 to 120 kV, the reshaped nanodot diameter enlarges from 12.7 ± 0.8 to 18.3 ± 3.6 nm due to the gradual self‐aggregation. In comparison with sputtering method, the electroactivity of Pt nanodot covered carbon fiber electrode obtained after electron‐beam reduction exhibits a larger electroactive surface (Spt) of 16.56 cm2/mg. The electron‐beam reduction provides a better dispersion of the reduced Pt nanodots based catalysts on carbon‐fiber electrode, promoting the utilization efficiency of these nanoscale catalyst (defined as the ratio of electroactive to geometric area) from 2.5% to 7%.
Quantum Theory, Noncommutative Gravity, and the Cosmological Constant Problem
Authors: Singh T. P.
Published: December 2009

The cosmological constant problem is principally concerned with trying to understand how the zero‐point
energy of quantum fields contributes to gravity. Here we take the approach that by addressing a
fundamental unresolved issue in quantum theory, we can gain a better understanding of the problem.
Our starting point is the observation that the notion of classical time is external to quantum mechanics.
Hence there must exist an equivalent reformulation of quantum mechanics which does not refer to an
external classical time. Such a reformulation is a limiting case of a more general quantum theory which
becomes nonlinear on the Planck mass/energy scale. The nonlinearity gives rise to a quantum‐classical
duality which maps a “strongly quantum, weakly gravitational” dynamics to a “weakly quantum, strongly
gravitational” dynamics. This duality predicts the existence of a tiny nonzero cosmological constant of
the order of the square of the Hubble constant, which could be a possible source for the observed cosmic
acceleration. Such a nonlinearity could also be responsible for the collapse of the wave function during a
quantum measurement.
Studies on the Biodiversity of Halophilic Microorganisms Isolated from El-Djerid Salt Lake (Tunisia) under Aerobic Conditions
Authors: Hedi Abdeljabbar , Sadfi Najla , Fardeau Marie-Laure , Rebib Hanene , Cayol Jean-Luc , Ollivier Bernard , Boudabous Abdellatif
Published: December 2009

Bacterial and archaeal aerobic communities were recovered from sediments from the shallow El-Djerid salt lake in Tunisia, and their salinity gradient distribution was established. Six samples for physicochemical and microbiological analyses were obtained from 6 saline sites in the lake for physico-chemical and microbiological analyses. All samples studied were considered hypersaline with NaCl concentration ranging from 150 to 260 g/L. A specific halophilic microbial community was recovered from each site, and characterization of isolated microorganisms was performed via both phenotypic and phylogenetic approaches. Only one extreme halophilic organism, domainArchaea, was isolated from site 4 only, whereas organisms in the domainBacteriawere recovered from the five remaining sampling sites that contained up to 250 g/L NaCl. Members of the domainBacteriabelonged to generaSalicola, Pontibacillus, Halomonas, Marinococcus, andHalobacillus, whereas the only member of domainArchaeaisolated belonged to the genusHalorubrum. The results of this study are discussed in terms of the ecological significance of these microorganisms in the breakdown of organic matter in Lake El-Djerid and their potential for industry applications.
The Use of Th in HTR: State of the Art and Implementation in Th/Pu Fuel Cycles
Authors: Mazzini Guido , Bomboni Eleonora , Cerullo Nicola , Fridman Emil , Lomonaco Guglielmo , Shwageraus Eugene
Published: December 2009

Nowadays nuclear is the only greenhouse‐free source that can appreciably respond to the increasing worldwide energy demand. The use of Thorium in the nuclear energy production may offer some advantages to accomplish this task. Extensive R&D on the thorium fuel cycle has been conducted in many countries around the world. Starting from the current nuclear waste policy, the EU‐PUMA project focuses on the potential benefits of using the HTR core as a Pu/MA transmuter. In this paper the following aspects have been analysed: (1) the state‐of‐the‐art of the studies on the use of Th in different reactors, (2) the use of Th in HTRs, with a particular emphasis on Th‐Pu fuel cycles, (3) an original assessment of Th‐Pu fuel cycles in HTR. Some aspects related to Thorium exploitation were outlined, particularly its suitability for working in pebble‐bed HTR in a Th‐Pu fuel cycle. The influence of the Th/Pu weight fraction at BOC in a typical HTR pebble was analysed as far as the reactivity trend versus burn‐up, the energy produced per Pu mass, and the Pu isotopic composition at EOC are concerned. Although deeper investigations need to be performed in order to draw final conclusions, it is possible to state that some optimized Th percentage in the initial Pu/Th fuel could be suggested on the basis of the aim we are trying to reach.
Mauriac Syndrome in a Child with a Positive Antinuclear Antibody Screen
Authors: Pohl John F.
Published: December 2009

A 17-year-old male with type 1 diabetes mellitus (T1DM) presented to clinic with elevated transaminases and a positive antinuclear antibody (ANA) screen. Due to concern for autoimmune hepatitis, a liver biopsy was performed which revealed Mauriac syndrome. This case report is the second known description of a child with Mauriac syndrome presenting with positive autoimmune markers.
Application of REPAS Methodology to Assess the Reliability of Passive Safety Systems
Authors: Pierro Franco , Araneo Dino , Galassi Giorgio , D′Auria Francesco
Published: December 2009

The paper deals with the presentation of the Reliability Evaluation of Passive Safety System (REPAS) methodology developed by University of Pisa. The general objective of the REPAS is to characterize in an analytical way the performance of a passive system in order to increase the confidence toward its operation and to compare the performances of active and passive systems and the performances of different passive systems. The REPAS can be used in the design of the passive safety systems to assess their goodness and to optimize their costs. It may also provide numerical values that can be used in more complex safety assessment studies and it can be seen as a support to Probabilistic Safety Analysis studies. With regard to this, some examples in the application of the methodology are reported in the paper. A best‐estimate thermal‐hydraulic code, RELAP5, has been used to support the analyses and to model the selected systems. Probability distributions have been assigned to the uncertain input parameters through engineering judgment. Monte Carlo method has been used to propagate uncertainties and Wilks′ formula has been taken into account to select sample size. Failure criterions are defined in terms of nonfulfillment of the defined design targets.
Detection of EBV Infection and Gene Expression in Oral Cancer from Patients in Taiwan by Microarray Analysis
Authors: Yen Ching-Yu , Lu Min-Chi , Tzeng Ching-Cherng , Huang Jia-Yan , Chang Hsueh-Wei , Chen Ruey-Shyang , Liu Shyun-Yeu , Liu Shih-Tung , Shieh Biehuoy , Li Ching
Published: December 2009

Epstein‐Barr virus is known to cause nasopharyngeal carcinoma. Although oral cavity is located close to the nasal pharynx, the pathogenetic role of Epstein‐Barr virus (EBV) in oral cancers is unclear. This molecular epidemiology study uses EBV genomic microarray (EBV‐chip) to simultaneously detect the prevalent rate and viral gene expression patterns in 57 oral squamous cell carcinoma biopsies (OSCC) collected from patients in Taiwan. The majority of the specimens (82.5%) were EBV‐positive that probably expressed coincidently the genes for EBNAs, LMP2A and 2B, and certain structural proteins. Importantly, the genes fabricated at the spots 61 (BBRF1, BBRF2, and BBRF3) and 68 (BDLF4 and BDRF1) on EBV‐chip were actively expressed in a significantly greater number of OSCC exhibiting exophytic morphology or ulceration than those tissues with deep invasive lesions (P = .0265 and .0141, resp.). The results may thus provide the lead information for understanding the role of EBV in oral cancer pathogenesis.
Robotic Systems for Meteor Observing and Moon Impact Flashes Detection in Spain
Authors: Madiedo José M. , Trigo-Rodríguez Josep M. , Ortiz José L. , Morales Nicolás
Published: December 2009

A robotic observatory has been setup in the south‐west of Spain with the aim to study meteoroids interacting with the Earth′s atmosphere and meteoroids impacting on the Moon′s surface. This is achieved by using an array of high‐sensitivity CCD video cameras and three automated Schmidt‐Cassegrain telescopes. We summarize here the main characteristics of this new facility.
Milk Products Containing Bioactive Tripeptides Have an Antihypertensive Effect in Double Transgenic Rats (dTGR) Harbouring Human Renin and Human Angiotensinogen Genes
Authors: Jauhiainen Tiina , Pilvi Taru , Cheng Zhong Jian , Kautiainen Hannu , Müller Dominik N. , Vapaatalo Heikki , Korpela Riitta , Mervaala Eero
Published: December 2009

Tripeptides isoleucyl-prolyl-proline (IPP) and valyl-prolyl-proline (VPP) act as ACE inhibitors in vitro. Double transgenic rats (dTGR) harbouring human renin and human angiotensinogen genes develop malignant hypertension due to increased angiotensin II formation. The present study was aimed to evaluate possible antihypertensive effect of IPP and VPP in this severe model. Four-week-old dTGR were randomized in three groups to receive: (1) water (control), (2) fermented milk containing IPP and VPP, and (3) IPP and VPP dissolved in water for three weeks. Fermented milk, but not peptides in water, attenuated the development of hypertension in dTGR by 19 mmHg versus the control group (P=.023). In vitro vascular function tests showed that high concentrations of the peptides evinced ACE inhibitory properties. In other hypertension related variables, no significant differences between the treatment groups were found. In conclusion, fermented milk product containing IPP and VPP prevents development of malignant hypertension in an animal model.
Directed Metalation of Heterocycles, 5-Methoxy-2-phenyloxazol-4-yllithium: An Approach to α,β-Dehydroamino Acids
Authors: Chandrasekhar Sosale , Srimannarayana Malempati
Published: December 2009

5-Methoxy-2-phenyloxazole was deprotonated at C4 (by n-BuLi or LDA, in THF at −78C∘). The resulting anion was generally unreactive to alkylation (except methylation with MeI-TMEDA) but added to PhCHO and Me2CHCHO. The alcohols thus produced dehydrated and ring opened in acid, to the corresponding α,β-dehydroamino acids in moderate overall yields.
A Neural Mass Model to Simulate Different Rhythms in a Cortical Region
Authors: Zavaglia M. , Cona F. , Ursino M.
Published: December 2009

An original neural mass model of a cortical region has been used to investigate the origin of EEG rhythms. The model consists of four interconnected neural populations: pyramidal cells, excitatory interneurons and inhibitory interneurons with slow and fast synaptic kinetics, and respectively. A new aspect, not present in previous versions, consists in the inclusion of a self-loop among interneurons. The connectivity parameters among neural populations have been changed in order to reproduce different EEG rhythms. Moreover, two cortical regions have been connected by using different typologies of long range connections. Results show that the model of a single cortical region is able to simulate the occurrence of multiple power spectral density (PSD) peaks; in particular the new inhibitory loop seems to have a critical role in the activation in gamma () band, in agreement with experimental studies. Moreover the effect of different kinds of connections between two regions has been investigated, suggesting that long range connections toward interneurons have a major impact than connections toward pyramidal cells. The model can be of value to gain a deeper insight into mechanisms involved in the generation of rhythms and to provide better understanding of cortical EEG spectra.
Gravitational Lensing as a Probe of Cold Dark Matter Subhalos
Authors: Zackrisson Erik , Riehm Teresa
Published: December 2009

In the cold dark matter scenario, dark matter halos are assembled hierarchically from smaller subunits. Some of these subunits are disrupted during the merging process, whereas others survive temporarily in the form of subhalos. A long‐standing problem with this picture is that the number of subhalos predicted by simulations exceeds the number of luminous dwarf galaxies seen in the vicinity of large galaxies like the Milky Way. Many of the subhalos must therefore have remained dark or very faint. If cold dark matter subhalos are as common as predicted, gravitational lensing may in principle offer a promising route to detection. In this paper, we describe the many ways through which lensing by subhalos can manifest itself, and summarize the results from current efforts to constrain the properties of cold dark matter subhalos using such effects.
Expression of CD44s in Incidental Prostate Cancer Is More Strongly Associated with Gleason Scores on Subsequent Radical Prostatectomies than Conventional Prognostic Parameters
Authors: Gunia Sven , May Matthias , Koch Stefan , Dietel Manfred , Erbersdobler Andreas
Published: December 2009

Objective: Incidental prostate cancer (IPC) has a substantially variable clinical course which cannot be predicted by conventional histopathologic examination of transurethral resection specimens of the prostate (TURP chips). Therefore, efforts should be directed towards defining the natural history of individual IPC. Recently, expression of CD44s (standard isoform), a transmembranous glycoprotein, has been linked to prognostic outcome in prostate cancer, but its prognostic role in IPC has been neglected so far. Methods: We present a multicentre study which evaluates immunohistochemically the largest cohort of IPC patients to date, aiming to correlate CD44s expression in the TURP chips with histopathologic outcome parameters (Gleason scores and histologic staging) performed on subsequent radical prostatectomies (RPs) in a cohort of 54 patients who underwent prostatectomy due to IPC. Results: CD44s expression recorded in the TURP chips showed a stronger (inverse) association with Gleason scores performed on the corresponding RPs than did other conventional prognostic variables and, therefore, might become a valuable adjunct to better predict outcome in IPC prior to radical prostatectomy. Conclusion: Advanced prospective studies should aim to define cut-point values of CD44s expression for separating aggressive tumours from their indolent counterparts, and should also assess possible associations with clinical follow-up data (e.g. progression-free survival) in IPC.
Pathophysiology of Osteoarthritis: Evidence against the Viscoelastic Theory
Authors: Dunn Sharon , Kolomytkin Oleg V. , Marino Andrew A.
Published: December 2009

Objectives: Whether changes in the hyaluronan moiety of synovial fluid are associated with osteoarthritis (OA) is unresolved experimentally, notwithstanding frequent statements in the literature that the disease leads to degraded hyaluronan. We evaluated this hypothesis by comparing the molecular weight and concentration of hyaluronan in synovial fluid from patients with and without OA. Methods: Synovial fluid was obtained by needle aspiration from patients with advanced OA (Kellgren-Lawrence Grade IV) and from patients with no radiological or arthroscopic evidence of OA. The distribution of the molecular weight of hyaluronan was measured using both gel electrophoresis and size-exclusion chromatography, and hyaluronan concentration was determined by immunosorbent assay and differential refractometry. Results: The distributions of molecular weight were highly variable within each group of patients; the average distributions, however, were identical in the 2 groups. The average concentration of hyaluronan also did not differ statistically between the 2 groups. Conclusions: We found no evidence of hyaluronan degradation in synovial fluid of patients with OA. Commonly expressed opinion in the literature to the contrary may have resulted from a failure to adequately consider the limitations of previous experimental studies.
Adaptive Cognitive Testing in Cerebrovascular Disease and Vascular Dementia
Authors: Wouters Hans , de Koning Inge , Zwinderman Aeilko H. , van Gool Willem A. , Schmand Ben , Buiter Maarten , Lindeboom Robert
Published: November 2009

Background/Aims: To examine whether brevity can be combined with precision in measuring global cognitive ability in patients with cerebrovascular disease (CVD) or vascular dementia (VaD). Longer tests (e.g. the CAMCOG) are precise but inefficient, whereas brief tests (e.g. the MMSE) are efficient but imprecise. Methods: A simulated computerized adaptive testing (CAT) algorithm using existing CAMCOG data from 284 patients with CVD of whom 55 were diagnosed with VaD. CAT was used to estimate each individual patient’s total score on a large precise test (the CAMCOG). CAT repeatedly selected only items of appropriate difficulty, depending on whether the previous item was (in)correctly responded to. CAT estimates were compared with total scores on the whole CAMCOG. Results: Even though there was an average test reduction of more than 40%, CAT estimates were in very high agreement with the whole test results (intraclass correlation >0.97) and had similar accuracy for the diagnosis of dementia (area under the curve = 0.94). Conclusion: CAT combines efficiency with precision in the measurement of global cognitive ability in CVD patients.
Unusual Location of Hydatid Cysts in Pediatric Patients
Authors: Dagtekin Ahmet , Koseoglu Aslihan , Kara Engin , Karabag Hamza , Avci Emel , Torun Fuat , Bagdatoglu Celal
Published: November 2009

Objective/Aims: To emphasize the importance of diagnosis and treatment of unusually localized hydatid cysts in pediatric cases. Methods: Hydatid cyst patients of two departments were listed who had undergone surgery between January 2001 and December 2008. Of the 7 pediatric patients, 3 were chosen as the ones with unusual localization. Cyst removal with Dowling’s technique was performed in 2 cases and total removal of the cyst wall was achieved after cyst aspiration in the other patient. Results: Two patients did not show any signs of recurrence. Some of the cranial multiple cysts of the patient who had undergone her first surgery in another clinic with cyst rupture were successfully removed in our clinic. Six months later, she was admitted with spinal seedings. Conclusion: Hydatid cyst removal without rupture should be the surgical goal in all cases. Radiological evaluation is of utmost importance for differential diagnosis. When a cystic lesion is found in the central nervous system on radiological evaluation, hydatid disease must be considered in countries where the disease is endemic and surgery is to be planned emergently especially for pediatric cases with increased intracranial pressure. The study focuses on the strategy for the correct diagnosis and the appropriate treatment of unusually localized hydatid cysts.
Bilateral Decompressive Craniectomy for Refractory Intracranial Hypertension in a Child with Severe ITP-Related Intracerebral Haemorrhage
Authors: Ranger Adrianna , Szymczak Artur , Fraser Douglas , Salvadori Marina , Jardine Lawrence
Published: November 2009

We report a 13-month-old infant who developed acutely elevated intracranial pressure (ICP) as a result of a spontaneous intracerebral haemorrhage (ICH), secondary to idiopathic thrombocytopenic purpura (ITP). Her ICP remained severely elevated despite aggressive medical measures, with persistent obtundation, right hemiparesis and a dilated left pupil. Bilateral decompressive craniectomies (DCs) were performed, which resulted in a rapid decline in ICP. Ultimately, the patient regained consciousness and went on to complete neurological recovery. Tragically, she died of non-neurological, ITP-related complications 9 months later. In our review, we identified no other instances of bilateral DCs reported in the management of an infant with ITP and/or an ICH. We addressed three central questions: (1) Is there any value of DCs in children, and especially in infants, with elevated ICP? (2) Is there any value of DCs in the setting of non-traumatic ICH? And (3) is there any rationale for the use of bilateral versus unilateral DCs?
Stroke in the Very Old: Incidence, Risk Factors, Clinical Features, Outcomes and Access to Resources – A 22-Year Population-Based Study
Authors: Béjot Yannick , Rouaud Olivier , Jacquin Agnès , Osseby Guy-Victor , Durier Jérôme , Manckoundia Patrick , Pfitzenmeyer Pierre , Moreau Thibault , Giroud Maurice
Published: December 2009

Background: For several years, the burden of stroke in very old patients has been increasing in western countries. Nevertheless, we have little information about this new challenge in individuals ≧80. Methods: We ascertained all first-ever strokes in the population of Dijon, France (150,000 inhabitants), from 1985 to 2006. The incidence of stroke, risk factors, clinical presentation, resource mobilization and 1-month outcome were evaluated in individuals ≧80 and compared to the data obtained in younger patients. Results: We collected 1,410 first-ever strokes in people ≧80 years (39%) versus 2,130 in those <80 years. The incidence was 997/100,000, and 68/100,000, respectively. Over the 22 years, the incidence of stroke in individuals ≧80 years rose significantly. A lower prevalence of diabetes, hypercholesterolemia and alcohol intake, as well as a higher prevalence of hypertension, atrial fibrillation, previous myocardial infarction and use of prestroke antiplatelet agents were noted in patients ≧80 years. The clinical presentation was severer and the 1-month outcome in terms of case fatality and handicap was worse, despite improvements observed over time. Finally, in patients ≧80 years, the use of CT scan, MRI, cervical Doppler, angiography and carotid surgery were significantly lower than for younger patients. Length of stay >30 days was more frequent, and discharge to prestroke residence was less common. However, all these improved between the first and the last study periods. Conclusions: Our findings have important implications not only for clinical management but also for initiating preventive strategies and health policy.
Low Bone Mineral Density Is an Independent Risk Factor for Stroke and Death
Authors: Nordström Anna , Eriksson Marie , Stegmayr Birgitta , Gustafson Yngve , Nordström Peter
Published: December 2009

Background: Recent studies suggest a relationship between atherosclerotic disease and osteoporosis. The aim of the study was to investigate whether bone mineral density (BMD) was prospectively related to stroke and death. Methods: BMD (g/cm2) was measured in 4,302 men and women (mean age 59 years, range 40–75) at baseline. The main outcome measures included validated strokes and death. Results: After a mean follow-up time of 5.6 years (range 0–15.8 years), 139 strokes were registered and 224 subjects had died. After adjustment for age, sex and body mass index, decreased femoral neck BMD and osteoporosis were found to be independent predictors of stroke (hazard ratio, HR, for each standard deviation decrease in BMD = 1.23, 95% CI = 1.01–1.49, and HR for osteoporosis = 1.92, 95% CI = 1.11–3.30). After adjustment for the same variables, the risk of death during follow-up was related to femoral neck BMD (HR = 1.41, 95% CI = 1.21–1.64) and osteoporosis at baseline (HR = 2.05, 95% CI = 1.28–3.29). Adjustment also for smoking, hypertension, hyperlipidemia and diabetes did not change any of these results. Conclusions: We found that decreased BMD as well as osteoporosis of the femoral neck are independently associated with stroke and death. Given the impact of osteoporosis and stroke on morbidity and mortality, this relationship is of high interest for further studies.
Comparison of Telephone and Face-to-Face Assessment of the Modified Rankin Scale
Authors: Janssen Paula M. , Visser Nora A. , Dorhout Mees Sanne M. , Klijn Catharina J.M. , Algra Ale , Rinkel Gabriel J.E.
Published: December 2009

Background: A structured interview improves the reliability of the modified Rankin Scale (mRS), a commonly used functional outcome scale in stroke trials. Telephone interview is a fast and convenient way to assess the mRS grade, but its validity is unknown. We assessed the validity of a telephone interview in patients who had had an aneurysmal subarachnoid haemorrhage (SAH) by comparing it with a face-to-face assessment. Methods: Eighty-three SAH patients were interviewed twice, once face-to-face and once by telephone, by 2 of 5 observers who used a structured interview to assess the mRS grade. Intermodality agreement was measured using weighted kappa statistics. To check for systematic differences between face-to-face and telephone assessment the Wilcoxon test for matched pairs was used. Results: Agreement between telephone and face-to-face assessment was perfect in 47 (57%) patients. A difference of 1 level occurred in 31 (37%) patients and this was almost equally distributed over the grades of the mRS. Weighted kappa was 0.71 (95% CI 0.59–0.82). Telephone assessment did not result in a consistently more or less favourable grade than face-to-face assessment (Wilcoxon test for matched pairs, p = 0.33). Conclusions: Telephone assessment of the mRS with a structured interview has a good agreement with face-to-face assessment and can thus be used reliably in the setting of a clinical trial.
Postendarterectomy Mortality in Octogenarians and Nonagenarians in the USA from 1993 to 1999
Authors: Lichtman Judith H. , Jones Sara B. , Wang Yun , Watanabe Emi , Allen Norrina B. , Fayad Pierre , Goldstein Larry B.
Published: December 2009

Background: Relatively little is known about trends in the utilization or outcomes of carotid endarterectomy (CEA) in the very elderly. We determined trends in the rates of CEA and perioperative (in-hospital and 30-day) and long-term (1-, 2-, 3-, 4- and 5-year) mortality in a US national sample of patients ≧80 years of age. Methods: All fee-for-service Medicare patients (80–89 and ≧90 years of age) who had a CEA [ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification): 38.12] from 1993 to 1999 were identified using the Centers for Medicare and Medicaid Services Inpatient Standard Analytic Files. Demographic characteristics and comorbid conditions were determined using ICD-9-CM diagnostic codes within the year prior to the index hospitalization for CEA. Results: A total of 140,376 CEA were performed in patients aged 80–89 years and 6,446 in those aged ≧90 years during this 7-year period. The annual number of operations increased from 13,115 in 1993 to 21,582 in 1999 for octogenarians, and from 481 in 1993 to 1,257 in 1999 for nonagenarians. Perioperative mortality was 2.2% in octogenarians and 3.3% in nonagenarians. Long-term mortality increased by approximately 10% per year after the operation, and was 43% in octogenarians and 56% in nonagenarians at 5 years. Perioperative mortality rates remained relatively stable over the 7-year period for both age groups although comorbidities increased. Conclusions: The number of CEA performed in the very elderly in the USA increased from 1993 to 1999. Perioperative mortality rates were high compared with trial results, while long-term survivorship was comparable to that of similarly-aged peers in the USA.
Isolated Anterior Cerebral Artery Territory Infarction: Dissection as an Etiological Mechanism
Authors: Sato Shoichiro , Toyoda Kazunori , Matsuoka Hideki , Okatsu Hideki , Kasuya Junji , Takada Tatsuro , Shimode Atsuko , Uehara Toshiyuki , Naritomi Hiroaki , Minematsu Kazuo
Published: December 2009

Background: Intracranial arterial lesions are important causes of ischemic stroke, particularly in the Asian population. Of the intracranial lesions, the etiology of isolated anterior cerebral artery (ACA) territory infarction is not fully elucidated. The purpose of this study was to determine the etiological and clinical characteristics of patients with isolated ACA territory infarction, especially those with ACA dissection. Methods: Of 3,115 consecutive patients with acute ischemic stroke, 42 patients (1.3%, 30 men, 38–88 years old) having an isolated ACA territory infarction were studied. Infarcts were principally verified by diffusion-weighted MRI, and vascular lesions were identified by MRA, CTA, or digital subtraction angiography. Three-dimensional rotational angiography was performed if needed. Results: Eighteen patients (43%) were diagnosed as having ACA dissection. The stroke subtypes of the other 24 patients included cardioembolism for 6 patients and large-artery atherosclerosis for 8. Patients with dissection were younger (p < 0.001) and heavier (p = 0.026), less commonly had heart disease (p = 0.002) and previous stroke (p = 0.002), and had lower initial systolic blood pressure (p = 0.029) and lower levels of D-dimer (p = 0.041) than patients without dissection. Stroke onset more commonly followed physical exertion (p = 0.013) and headache (p = 0.041) in patients with dissection than in patients without dissection. At hospital discharge, the modified Rankin scale score was lower in patients with dissection than in patients without dissection (p = 0.005). Conclusions: Arterial dissection was the most common vascular lesion underlying an isolated ACA territory infarction in our Japanese cohort. Patients with ACA dissection had unique baseline characteristics and unique conditions at stroke onset.
Electrocardiogram QT Interval Increases in Acute Stroke
Authors: Mulcahy James , Johnson Paul , James Martin
Published: December 2009

Background and Objective: Acute stroke patients have a greater QT interval (QT) and QT interval dispersion than case controls, but evidence for a causal association between stroke and electrocardiogram (ECG) changes is limited because studies examined QT interval after stroke only. This retrospective observational study examined the change in QT interval around the time of acute stroke by comparing pre- and post-stroke ECGs. Methods: QT was measured from all leads of the most recent pre-stroke and the earliest post-stroke ECGs of patients admitted with cerebral infarction or haemorrhage. QTmax (the longest QT interval) and QTmin (the shortest) for each ECG were identified. Results: Data from 45 patients were analysed, mean age = 80 years, 87% ischaemic strokes. The mean increase for QTmax was 14.9 ms (95% CI = 6.1–23.7, p < 0.01), for QTmin 10.8 ms (95% CI = 2.5–19.0, p < 0.02) and for QT dispersion 4.1 ms (p = 0.14). No significant differences in QT change were found for different stroke subtypes or side of stroke. Regression analysis revealed no significant confounding variables. Conclusions: This study demonstrates an increase in QTmax and QTmin following acute stroke, while the QT rise was not significant. Negative results of analysis for potential confounders suggested that the increase in QT interval is probably due to the effect of acute stroke on cardiac autonomic function. A larger study may demonstrate a relation between QT disturbance and cerebral infarct size and site.
Curcumin Attenuates Glucose-Induced Monocyte Chemoattractant Protein-1 Synthesis in Aortic Endothelial Cells by Modulating the Nuclear Factor-ĸB Pathway
Authors: Panicker Sumith Retnamma , Kartha Chandrasekharan Cheranellore
Published: December 2009

Background/Aims: High glucose (HG) induces monocyte chemoattractant protein-1 (MCP-1) synthesis in endothelial cells through nuclear factor ĸB (NFĸB). We investigated whether curcumin, losartan and sodium salicylate (NaSal) attenuate HG-induced MCP-1 synthesis in rat aortic endothelial cells (RAECs) and explored the mechanism of action. Methods: RAECs were stimulated with HG (25 mmol/l) for 24 h in the presence or absence of curcumin, losartan, NaSal or NFĸB inhibitor, Bay 11-0782. The MCP-1 protein and mRNA levels were determined by enzyme-linked immunosorbent assay and real-time reverse transcriptase-polymerase chain reaction, respectively. Nuclear translocation of NFĸB subunit p65 and NFĸB DNA-binding activity was studied using confocal microscopy and electrophoretic mobility shift assay, respectively. Results: A significant increase in the synthesis of MCP-1 protein and mRNA (2-fold) was observed in HG-primed RAECs compared to control glucose (5.5 mmol/l). Curcumin (30 µmol/l) significantly decreased HG-induced MCP-1 protein (74%) and mRNA (53%) synthesis. There was no inhibition of HG-induced MCP-1 protein secretion by losartan and NaSal. In HG-stimulated RAECs, curcumin attenuated the nuclear translocation of p65 and decreased the NFĸB DNA-binding activity. Conclusion: Curcumin blocks HG-induced MCP-1 synthesis in RAECs partly via the NFĸB pathway.
A Dynamic Systems Approach to the Effects of Aging on Bimanual Coordination
Authors: Temprado Jean-Jacques , Vercruysse Sarah , Salesse Robin , Berton Eric
Published: November 2009

The present study examined the effects of aging on the execution of a bimanual coordination task in a classical phase transition paradigm in which coordination patterns (in-phase and anti-phase) and movement frequency were manipulated. Two groups of adults, the so-called young (average age 26 years) and old (average age 71 years) participants, performed both in-phase and anti-phase patterns at different frequencies. As we expected variability of relative phase was larger for older participants than for younger ones for both the in-phase and the anti-phase coordination patterns. Moreover, phase transitions occurred at lower frequencies for older participants and more transitions were observed for older than for younger participants. Although no specific hypotheses were made about the prominent source(s) of age-related changes in coordination dynamics (i.e., an alteration in the coupling function and/or an increase of the magnitude of noise), our results suggest that these changes might result from increases in the (neural) noise to be found in the (bimanual) action system.
Regulation of Hypoxia-Inducible Genes by PGC-1α
Authors: Shoag Jonathan , Arany Zolt
Published: December 2009

Atmospheric oxygen appeared approximately 2.3 billion years ago and sustains most complex life on earth. As mitochondria evolved to harness the energy in oxygen, systems developed to sense and respond to local oxygen concentrations and metabolic conditions. For more than a decade, research has focused on hypoxia-inducible factor 1 (HIF1), a key component of the eukaryotic oxygen-response system. Recently, evidence for other systems has also surfaced. One of these systems involves the PGC-1α coactivator, a powerful transcriptional regulator of mitochondria and oxidative metabolic programs. This brief review will focus on this burgeoning role for PGC-1α and will highlight the many questions that remain unanswered.
Vitamin D Receptor Activators Induce an Anticalcific Paracrine Program in Macrophages
Authors: Li Xianwu , Speer Mei Y. , Yang Hsueh , Bergen Jamie , Giachelli Cecilia M.
Published: December 2009

Objectives—

Vascular calcification is highly correlated with morbidity and mortality, and it is often associated with inflammation. Vitamin D may regulate vascular calcification and has been associated with cardiovascular survival benefits.

Methods and Results—

We developed a macrophage/smooth muscle cell (SMC) coculture system and examined the effects of vitamin D receptor activators (VDRA), calcitriol and paricalcitol, on SMC matrix calcification. We found that treatment of SMC alone with VDRA had little effect on phosphate-induced SMC calcification in vitro. However, coculture with macrophages promoted SMC calcification, and this was strikingly inhibited by VDRA treatment. Several VDRA-induced genes, including bone morphogenetic protein-2 (BMP2), tumor necrosis factor-α, and osteopontin, were identified as candidate paracrine factors for the protective effect of VDRA. Of these, osteopontin was further investigated and found to contribute significantly to the inhibitory actions of VDRA on calcification in macrophage/SMC cocultures.

Conclusion—

The ability of VDRA to direct a switch in the paracrine phenotype of macrophages from procalcific to anticalcific may contribute to their observed cardiovascular survival benefits.
Conjoint Effects of Serum Calcium and Phosphate on Risk of Total, Cardiovascular, and Noncardiovascular Mortality in the Community
Authors: Larsson Tobias E. , Olauson Hannes , Hagström Emil , Ingelsson Erik , Ärnlöv Johan , Lind Lars , Sundström Johan
Published: December 2009

Objective—

Hyperphosphatemia is a cardiovascular risk factor in patients with chronic kidney disease. Relations of circulating calcium (Ca) and phosphorus (Pi) to long-term mortality risk in the community require further investigation.

Methods and Results—

Associations of serum Ca and Pi to mortality were evaluated in a community-based cohort of 2176 men (mean age, 50.1 years). During follow-up (median, 29.8 years), 1009 men died, and 466 of these deaths resulted from cardiovascular causes. In Cox proportional hazards models, serum Pi and [Ca×Pi] were independent predictors of total mortality (hazard ratio per SD, 1.06; 95% CI, 1.01–1.12;
P
=0.03; 1.07; 95% CI, 1.01–1.12;
P
=0.01) and cardiovascular mortality (1.10; 95% CI, 1.02–1.18;
P
=0.01; 1.10; 95% CI, 1.03–1.19;
P
=0.008). Serum Ca was associated with risk of total mortality (1.08; 95% CI, 1.01–1.16;
P
=0.02) and noncardiovascular mortality (1.10; 95% CI, 1.01–1.21;
P
=0.04). Results were consistent after multivariate adjustments in subsamples of individuals with estimated glomerular filtration rate >90 mL/min and low-to-normal serum Ca and Pi.

Conclusion—

Circulating Ca and Pi levels are associated with risks of total, cardiovascular, and noncardiovascular mortality in the community, and their conjoint effects are additive. Additional studies are warranted to evaluate whether Ca and Pi are modifiable risk factors in the general population.
Differential Clinical Outcomes Associated With Hypoglycemia and Hyperglycemia in Acute Myocardial Infarction
Authors: Goyal Abhinav , Mehta Shamir R. , Díaz Rafael , Gerstein Hertzel C. , Afzal Rizwan , Xavier Denis , Liu Lisheng , Pais Prem , Yusuf Salim
Published: December 2009

Background—

In patients with acute myocardial infarction (AMI), hyperglycemia predicts death, but the prognostic significance of hypoglycemia is controversial.

Methods and Results—

We evaluated the prognostic significance of hypoglycemia and hyperglycemia in 30 536 AMI patients in a post hoc analysis of 2 large trials of glucose-insulin-potassium therapy in AMI. Glucose levels on admission and at 6 and 24 hours after admission, as well as 30-day mortality, were documented. In separate multivariable Cox models for admission and postadmission glucose, we compared the prognostic value of hypoglycemia (≤70 mg/dL) and hyperglycemia (≥140 mg/dL) with normoglycemia (>70 and <140 mg/dL). Analyses were repeated with hypoglycemia defined as glucose ≤60 mg/dL and in key subgroups based on diabetes or insulin (glucose-insulin-potassium) allocation status. Both high and low percentiles of admission glucose predicted increased 30-day mortality. However, for postadmission glucose, this U-shaped relationship was attenuated so that only high and not low glucose levels remained prognostic. Hyperglycemia (≥140 mg/dL), both on admission (adjusted hazard ratio 1.43, 95% confidence interval 1.32 to 1.56,
P
<0.0001) and after admission (adjusted hazard ratio 1.47, 95% confidence interval 1.31 to 1.66,
P
<0.0001), predicted death compared with normoglycemia. In contrast, hypoglycemia (glucose ≤70 mg/dL) on admission was not prognostic (adjusted hazard ratio 1.16, 95% confidence interval 0.84 to 1.62,
P
=0.37), nor was postadmission hypoglycemia (adjusted hazard ratio 0.96, 95% confidence interval 0.72 to 1.26,
P
=0.75). Exploratory analyses that redefined hypoglycemia as glucose ≤60 mg/dL showed consistent results, as did analyses restricted to diabetic patients (18% of the study population). Postadmission hypoglycemia was more common in insulin (glucose-insulin-potassium)–treated patients (6.9%) than in untreated patients (3.4%) but did not predict mortality in either subgroup.

Conclusions—

Both admission and postadmission hyperglycemia predict 30-day death in AMI patients. In contrast, only hypoglycemia on admission predicted death, and this relationship dissipated after admission. These data suggest hypoglycemia may not be a direct mediator of adverse outcomes in AMI patients.
Toll-Like Receptor-2 Mediates Inflammation and Matrix Degradation in Human Atherosclerosis
Authors: Monaco Claudia , Gregan Scott M. , Navin Tina J. , Foxwell Brian M.J. , Davies Alun H. , Feldmann Marc
Published: December 2009

Background—

Inflammation and matrix degradation are the hallmarks of high-risk atherosclerosis that leads to myocardial infarction and stroke. Toll-like receptors (TLRs), key players in innate immunity, are upregulated in atherosclerotic lesions, but their functional role in human atherosclerosis is unknown. We explored the effects of blocking TLR-2, TLR-4, and myeloid differentiation primary response gene 88 (MyD88), a signaling adaptor shared by most TLRs and interleukin-1 receptor (IL-1R), in an in vitro model of human atherosclerosis.

Methods and Results—

Carotid endarterectomies were obtained from patients with symptomatic carotid disease. Cells were isolated via enzymatic tissue dissociation and cultured in the presence or absence of TLR signaling blockers. A dominant-negative form of MyD88 (MyD88
DN
) decreased the production of monocyte chemotactic protein-1/CCL2 (
P
=0.000), IL-8/CXCL8 (
P
=0.006), IL-6 (
P
=0.002), matrix metalloproteinase-1 (MMP-1;
P
=0.002), and MMP-3 (
P
=0.000), as well as nuclear factor-κB activation (
P
<0.05) in atheroma cell cultures. IL-1R antagonist, TLR-4 blocking antibodies, or overexpression of a dominant-negative form of the TLR-4 signaling adaptor TRIF-related adaptor molecule reduced nuclear factor-κB activity but did not have a broad impact on the production of the mediators studied. In contrast, TLR-2 neutralizing antibodies inhibited nuclear factor-κB activation (
P
<0.05) and significantly reduced monocyte chemotactic protein-1/CCL2 (
P
=0.000), IL-8/CXCL8 (
P
=0.009), IL-6 (
P
=0.000), and MMP-1 (
P
=0.000), MMP-2 (
P
=0.004), MMP-3 (
P
=0.000), and MMP-9 (
P
=0.006) production.

Conclusions—

Our data indicate that TLR-2 signaling through MyD88 plays a predominant role in inflammation and matrix degradation in human atherosclerosis. TLR-2 blockade may represent a therapeutic strategy for atherosclerosis and its complications.