bluuebunny/crossref_metadata_2025 huggingface dataset:
Diverse Effects of Glutathione and UPF Peptides on Antioxidant Defense System in Human Erythroleukemia Cells K562
Authors: Kairane Ceslava , Mahlapuu Riina , Ehrlich Kersti , Kilk Kalle , Zilmer Mihkel , Soomets Ursel
Published: February 2012

The main goal of the present paper was to examine the influence of the replacement ofγ-Glu moiety toα-Glu in glutathione and in its antioxidative tetrapeptidic analogue UPF1 (Tyr(Me)-γ-Glu-Cys-Gly), resulting inα-GSH and UPF17 (Tyr(Me)-Glu-Cys-Gly), on the antioxidative defense system in K562 cells. UPF1 and GSH increased while UPF17 andα-GSH decreased the activity of CuZnSOD in K562 cells, at peptide concentration of 10 μM by 42% and 38% or 35% and 24%, respectively. After three-hour incubation, UPF1 increased and UPF17 decreased the intracellular level of total GSH. Additionally, it was shown that UPF1 is not degraded byγ-glutamyltranspeptidase, which performs glutathione breakdown. These results indicate that effective antioxidative character of peptides does not depend only on the reactivity of the thiol group, but also of the other functional groups, and on the spatial structure of peptides.
Incorporating a Sorghum Habitat for Enhancing Lady Beetles (Coleoptera: Coccinellidae) in Cotton
Authors: Tillman P. G. , Cottrell T. E.
Published: February 2012

Lady beetles (Coleoptera: Coccinellidae) prey on insect pests in cotton. The objective of this 2 yr on-farm study was to document the impact of a grain sorghum trap crop on the density of Coccinellidae on nearby cotton.Scymnusspp.,Coccinella septempunctata(L.),Hippodamia convergensGuérin-Méneville,Harmonia axyridis(Pallas),Coleomegilla maculata(De Geer),Cycloneda munda(Say), andOlla v-nigrum(Mulsant) were found in sorghum over both years. Lady beetle compositions in sorghum and cotton and in yellow pyramidal traps were similar. For both years, density of lady beetles generally was higher on cotton with sorghum than on control cotton. Our results indicate that sorghum was a source of lady beetles in cotton, and thus incorporation of a sorghum habitat in farmscapes with cotton has great potential to enhance biocontrol of insect pests in cotton.
A Two-Stage Joint Model for Nonlinear Longitudinal Response and a Time-to-Event with Application in Transplantation Studies
Authors: Murawska Magdalena , Rizopoulos Dimitris , Lesaffre Emmanuel
Published: February 2012

In transplantation studies, often longitudinal measurements are collected for important markers prior to the actual transplantation. Using only the last available measurement as a baseline covariate in a survival model for the time to graft failure discards the whole longitudinal evolution. We propose a two-stage approach to handle this type of data sets using all available information. At the first stage, we summarize the longitudinal information with nonlinear mixed-effects model, and at the second stage, we include the Empirical Bayes estimates of the subject-specific parameters as predictors in the Cox model for the time to allograft failure. To take into account that the estimated subject-specific parameters are included in the model, we use a Monte Carlo approach and sample from the posterior distribution of the random effects given the observed data. Our proposal is exemplified on a study of the impact of renal resistance evolution on the graft survival.
On Applicability of a Miniaturised Laser Ablation Time of Flight Mass Spectrometer for Trace Elements Measurements
Authors: Tulej Marek , Riedo Andreas , Iakovleva Maria , Wurz Peter
Published: February 2012

We present results from mass spectrometric analysis of NIST standard materials and meteoritic samples conducted by a miniaturised laser ablation mass spectrometer designed for space research. The mass analyser supports investigation with a mass resolution () ≈ 500–600 and dynamic range within seven decades. Nevertheless, to maintain an optimal spectral quality laser irradiances lower than ~1 GW/cm2 are applied so far which results in a spread of RSC values. To achieve the quantitative performance of mass analyser, various effects influencing RSC factors have to be investigated. In this paper we investigate influence of laser irradiance, sampling procedure and plasma chemistry on the quantitative elemental and isotopic analysis. The studies indicate necessity for accurate control of laser characteristics and acquisition procedure. A relatively low irradiance applied causes a negligible sample damage and allows for accumulation of large number of waveforms from one sample location. The procedure yields statistically well averaged data and allows a sensitive in-depth analysis. The quantitative analyses of isotopic composition can be performed with accuracy and precision better as 1% and 2%, for isotopic patterns of elements and clusters, respectively. The numerical integration methods would be preferred to achieve more accurate results. The measurements of Allende sample yield detection of Pb isotopic pattern, nevertheless cluster species are readily observed in spectrum and make the elemental analysis of other trace elements difficult due to isobaric interferences. These detections are of a considerable interest because of possible application of the instrument for in situ elemental and isotopic analysis and radiometric dating of solids.
Stability Conditions for Fuzzy Neural Networks
Authors: Ahn Choon Ki
Published: February 2012

This paper presents a novel approach to assess the stability of fuzzy neural networks. First, we propose a new condition for the stability of fuzzy neural networks. Second, a new stability condition based on linear matrix inequality (LMI) is presented for fuzzy neural networks. These conditions also ensure asymptotic stability without external input.
Transient Response of Thin Wire above a Layered Half-Space Using TDIE/FDTD Hybrid Method
Authors: Wei Bing , He Qiong , Li Jie , Li Ren-xian , Guo Li-xin
Published: February 2012

The TDIE/FDTD hybrid method is applied to calculate the transient responses of thin wire above a lossy layered half-space. The time-domain reflection of the layered half space is computed by one-dimensional modified FDTD method. Then, transient response of thin wire induced by two excitation sources (the incident wave and reflected wave) is calculated by TDIE method. Finally numerical results are given to illustrate the feasibility and high efficiency of the presented scheme.
Centella asiaticaExtract Improves Behavioral Deficits in a Mouse Model of Alzheimer's Disease: Investigation of a Possible Mechanism of Action
Authors: Soumyanath Amala , Zhong Yong-Ping , Henson Edward , Wadsworth Teri , Bishop James , Gold Bruce G. , Quinn Joseph F.
Published: February 2012

Centella asiatica(CA), commonly named gotu kola, is an Ayurvedic herb used to enhance memory and nerve function. To investigate the potential use of CA in Alzheimer's disease (AD), we examined the effects of a water extract of CA (GKW) in the Tg2576 mouse, a murine model of AD with high β-amyloid burden. Orally administered GKW attenuated β-amyloid-associated behavioral abnormalities in these mice.In vitro, GKW protected SH-SY5Y cells and MC65 human neuroblastoma cells from toxicity induced by exogenously added and endogenously generated β-amyloid, respectively. GKW prevented intracellular β-amyloid aggregate formation in MC65 cells. GKW did not show anticholinesterase activity or protect neurons from oxidative damage and glutamate toxicity, mechanisms of current AD therapies. GKW is rich in phenolic compounds and does not contain asiatic acid, a known CA neuroprotective triterpene. CA thus offers a unique therapeutic mechanism and novel active compounds of potential relevance to the treatment of AD.
Water-Based Assembly and Purification of Plasmon-Coupled Gold Nanoparticle Dimers and Trimers
Authors: Bidault Sébastien , Polman Albert
Published: February 2012

We describe a simple one-pot water-based scheme to produce gold nanoparticle groupings with short interparticle spacings. This approach combines a cross-linking molecule and a hydrophilic passivation layer to control the level of induced aggregation. Suspensions of dimers and trimers are readily obtained using a single electrophoretic purification step. The final interparticle spacings allow efficient coupling of the particle plasmon modes as verified in extinction spectroscopy.
Demethoxycurcumin Retards Cell Growth and Induces Apoptosis in Human Brain Malignant Glioma GBM 8401 Cells
Authors: Huang Tzuu-Yuan , Hsu Che-Wen , Chang Weng-Cheng , Wang Miin-Yau , Wu June-Fu , Hsu Yi-Chiang
Published: February 2012

Demethoxycurcumin (DMC; a curcumin-related demethoxy compound) has been recently shown to display antioxidant and antitumor activities. It has also produced a potent chemopreventive action against cancer. In the present study, the antiproliferation (using the MTT assay, DMC was found to have cytotoxic activities against GBM 8401 cell with IC50values at 22.71 μM) and induced apoptosis effects of DMC have been investigated in human brain malignant glioma GBM 8401 cells. We have studied the mitochondrial membrane potential (MMP), DNA fragmentation, caspase activation, and NF-κB transcriptional factor activity. By these approaches, our results indicated that DMC has produced an inhibition of cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects were observed to increase in proportion with the dosage of DMC treatment, and the apoptosis was induced by DMC in human brain malignant glioma GBM 8401 cells via mitochondria- and caspase-dependent pathways.
Oral versus Long-Acting Injectable Antipsychotics in the Treatment of Schizophrenia and Special Populations at Risk for Treatment Nonadherence: A Systematic Review
Authors: Zhornitsky Simon , Stip Emmanuel
Published: February 2012

Long-acting injectable antipsychotics (LAIs) should offer better efficacy and tolerability, compared to oral antipsychotics due to improved adherence and more stable pharmacokinetics. However, data on LAIs has been mixed, with some studies finding that they are more effective and tolerable than oral antipsychotics, and others finding the contrary. One possibility for the disparate results may be that some studies administered different antipsychotics in the oral and injectable form. The present systematic review examined the efficacy and tolerability of LAIs versus their oral equivalents in randomized and naturalistic studies. In addition, it examined the impact of LAIs on special populations such as patients with first-episode psychosis, substance use disorders, and a history of violence or on involuntary outpatient commitment. Randomized studies suggest that not all LAIs are the same; for example, long-acting risperidone may be associated with equal or less side effects than oral risperidone, whereas fluphenazine decanoate and enanthate may be associated with equal or more side effects than oral fluphenazine. They also suggest that LAIs reduce risk of relapse versus oral antipsychotics in schizophrenia outpatients when combined with quality psychosocial interventions. For their part, naturalistic studies point to a larger magnitude of benefit for LAIs, relative to their oral equivalents particularly among first-episode patients.
FGA Temperature Control for Incubating Egg
Authors: Yusuf Ismail , Yusuf Yusram , Iksan Nur
Published: February 2012

This paper investigates the use of genetic algorithms (GA) in the design and implementation of fuzzy logic controllers (FLC) for incubating egg. What is the best to determine the membership function is the first question that has been tackled. Thus it is important to select the accurate membership functions, but these methods possess one common weakness where conventional FLC use membership function generated by human operators. The membership function selection process is done with trial and error, and it runs step by step which takes too long in solving the problem. This paper develops a system that may help users to determine the membership function of FLC using the GA optimization for the fastest processing in solving the problems. The data collection is based on the simulation results, and the results refer to the transient response specification which is maximum overshoot. From the results presented, we will get a better and exact result; the value of overshot is decreasing from 1.2800 for FLC without GA to 1.0081 with GA (FGA).
Eggs of the Blind Snake,Liotyphlops albirostris, Are Incubated in a Nest of the Lower Fungus-Growing Ant,  Apterostigmacf.goniodes
Authors: Bruner Gaspar , Fernández-Marín Hermógenes , Touchon Justin C. , Wcislo William T.
Published: February 2012

Parental care is rare in most lower vertebrates. By selecting optimal oviposition sites, however, mothers can realize some benefits often associated with parental care. We found three ovoid reptilian eggs within a mature nest of a relatively basal fungus-growing ant,Apterostigmacf.goniodes(Attini), in central Panama. In laboratory colonies,A.cf.goniodesworkers attended and cared for the eggs. Two blind snakes,Liotyphlops albirostris(Anomalepididae), successfully hatched, which is the first rearing record for this species. The ants did not disturb the snakes, and the snakes did not eat the ants; we found no ants in the dissected stomachs of the snakes. We review other associations between nesting fungus-growing ants and egg-laying vertebrates, which together suggest that attine nests may provide a safe, environmentally buffered location for oviposition, even in basal attine taxa with relatively small colony sizes.
Variation of the Gravitational Constant in the Radiation-Dominated Universe
Authors: Williams L. L.
Published: February 2012

The unification of classical electrodynamics and general relativity within the context of five-dimensional general relativity (Kaluza, 1921, and Thiry, 1948) contains a scalar field which may be identified with the gravitational constant, G. The field equations of this theory are solved under conditions of the Robertson-Walker metric for flat space, for a radiation-dominated universe—a model appropriate for the early history of our universe. This leads to a cosmology wherein G is inversely proportional to the Robertson-Walker scale factor. This result is discussed in the context of the Dirac large number hypothesis and in the context of an expression for G in terms of atomic constants.
Irinotecan Plus Mitomycin C as Second-Line Chemotherapy for Advanced Gastric Cancer Resistant to Fluoropyrimidine and Cisplatin: A Retrospective Study
Authors: Ogawa Kohei , Hosokawa Ayumu , Ueda Akira , Saito Seiko , Mihara Hiroshi , Ando Takayuki , Kajiura Shinya , Terada Mitsuhiro , Tsukioka Yuji , Horikawa Naoki , Kobayashi Takashi , Note Masayuki , Sawasaki Kunihiro , Fukuoka Junya , Sugiyama Toshiro
Published: February 2012

Background. S-1 plus cisplatin has been established to be standard first-line chemotherapy for advanced gastric cancer in Japan. The optimal second-line treatment refractory to S-1 plus cisplatin remains unclear.Methods. We retrospectively studied the efficacy, toxicity, and survival of irinotecan plus mitomycin C in patients with advanced gastric cancer refractory to a fluoropyrimidine plus cisplatin.Results. Twenty-four patients were studied. Prior chemotherapy was S-1 plus cisplatin in 15 patients, S-1 plus cisplatin and docetaxel in 8, and 5-fluorouracil plus cisplatin with radiotherapy in 1. The overall response rate was 17.4%. The median overall survival was 8.6 months, and the median progression-free survival was 3.6 months. Grade 3 or 4 toxicities included leukopenia (33%), neutropenia (50%), anemia (33%), thrombocytopenia (4%), anorexia (13%), diarrhea (4%), and febrile neutropenia (13%).Conclusion. A combination of irinotecan and mitomycin C is potentially effective in patients with advanced gastric cancer refractory to a fluoropyrimidine plus cisplatin.
Liver Disorders in Inflammatory Bowel Disease
Authors: Uko Victor , Thangada Suraj , Radhakrishnan Kadakkal
Published: February 2012

Disorders of the hepatobiliary system are relatively common extraintestinal manifestations of inflammatory bowel disease (IBD). These disorders are sometimes due to a shared pathogenesis with IBD as seen in primary sclerosing cholangitis (PSC) and small-duct primary sclerosing cholangitis (small-duct PSC). There are also hepatobiliary manifestations such as cholelithiasis and portal vein thrombosis that occur due to the effects of chronic inflammation and the severity of bowel disease. Lastly, medications used in IBD such as sulfasalazine, thiopurines, and methotrexate can adversely affect the liver. It is important to be cognizant of these disorders as some do have serious long-term consequences. The management of these disorders often requires the expertise of multidisciplinary teams to achieve the best outcomes.
Spondyloarthropathies in Autoimmune Diseases and Vice Versa
Authors: Pérez-Fernández Oscar M. , Mantilla Rubén D. , Cruz-Tapias Paola , Rodriguez-Rodriguez Alberto , Rojas-Villarraga Adriana , Anaya Juan-Manuel
Published: February 2012

Polyautoimmunity is one of the major clinical characteristics of autoimmune diseases (ADs). The aim of this study was to investigate the prevalence of ADs in spondyloarthropathies (SpAs) and vice versa. This was a two-phase cross-sectional study. First, we examined the presence of ADs in a cohort of patients with SpAs (N=148). Second, we searched for the presence of SpAs in a well-defined group of patients with ADs (N=1077) including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren’s syndrome (SS). Among patients with SpAs, ankylosing spondylitis was observed in the majority of them (55.6%). There were two patients presenting with SS in the SpA group (1.4%) and 5 patients with autoimmune thyroiditis (3.5%). The global prevalence of ADs in SpAs was 4.86%. In the ADs group, there were 5 patients with SpAs (0.46%). Our results suggest a lack of association between SpAs and ADs. Accordingly, SpAs might correspond more to autoinflammatory diseases rather than to ADs.
Functional Parathyroid Cyst: A Rare Cause of Malignant Hypercalcemia with Primary Hyperparathyroidism—A Case Report and Review of the Literature
Authors: Khan Areej , Khan Yusra , Raza Shahzad , Akbar Ghulam , Khan Monis , Diwan Nauman , Rizvi Wajih
Published: February 2012

Parathyroid cysts are rare lesions found in the neck and anterior mediastinum. They are often nonfunctional (>90%) and rarely in the functional form. This paper discusses a case of severe hypercalcemia (23 mg/dL) secondary to a rare functional parathyroid cyst. The patient was later found to have a hemorrhagic cyst with compression of the right recurrent laryngeal nerve. Preoperative diagnosis of the lesion was parathyroid carcinoma. However, reexploration of the parathyroid mass along with microscopic study confirmed the diagnosis of a parathyroid cyst. Following cystectomy, the patient restored her baseline functional status with preservation of the right recurrent laryngeal nerve. Postoperative followup three years later showed no evidence of cyst recurrence. This paper illustrates the rare presentation of parathyroid functional cysts with severe hypercalcemia and primary hyperparathyroidism. Physicians should be aware of the presence of hemorrhage, inflammation, and compressive symptoms in these cysts which mimic parathyroid carcinoma. These patients should be managed with aggressive medical and surgical intervention.
Fungal Enzymes for Environmental Purposes, a Molecular Biology Challenge
Authors: Ayala Marcela , Pickard Michael A. , Vazquez-Duhalt Rafael
Published: February 2012

In their capacity to transform xenobiotics and polluting compounds, fungal peroxidases and their use in the environmental field have a recognized and important potential. However, both fundamental and practical issues, such as enzyme stability and availability, have delayed the development of industrial applications. Three main protein engineering challenges have been identified: (1) Enhancement of operational stability, specifically hydrogen peroxide stability in the case of fungal peroxidases. (2) Increase of the enzyme redox potential in order to widen the substrate range. (3) Development of heterologous expression and industrial production. The bottlenecks, advances and strategies that have been proven successful are discussed.
Public Health Genomics and Genetic Test Evaluation: The Challenge of Conducting Behavioural Research on the Utility of Lifestyle-Genetic Tests
Authors: Sanderson Saskia C. , Wardle Jane , Humphries Steve E.
Published: February 2012

Human genetics research is increasingly concerned with multifactorial conditions such as diabetes and heart disease, which are influenced not only by genetic but also lifestyle factors such as diet and smoking. Although the results of ‘lifestyle-genetic’ tests using this information could conceivably motivate lifestyle changes in the future, companies are already selling such tests and related lifestyle advice commercially. Some academics and lobby groups have condemned the companies for selling these tests in advance of scientific support. Others are concerned that the tests may not motivate lifestyle improvements, instead causing distress in people receiving adverse test results and complacency in those receiving reassuring results. There is currently no regulatory oversight of genetic test utility, despite consensus in the Public Health Genomics community that clinical utility (including psychological and behavioural impact) of all emerging genetic tests should be evaluated before being introduced for individual use. Clearly, empirical data in this area is much needed, to inform understanding of the potential utility of these tests, and of whether stricter regulation of commercial exploitation is needed. In this article, we review the current situation regarding lifestyle-genetic tests, and discuss the challenges inherent in conducting this kind of behavioural research in the genomics era.
Obsessive-Compulsive Spectrum Disorders in Obsessive-Compulsive Disorder and Other Anxiety Disorders
Authors: Lochner Christine , Stein Dan J.
Published: February 2012

Background: There has been debate about whether obsessive-compulsive disorder (OCD) should be classified as one of the anxiety disorders, or should rather be categorized with obsessive-compulsive spectrum conditions. Sampling and Methods: The question of where OCD should be located in the diagnostic system was addressed by investigating the relationship of OCD, obsessive-compulsive spectrum disorders (OCSDs), and anxiety disorders. We administered a structured diagnostic interview (the SCID-OCSD) for assessing putative OCSDs in patients who presented with a primary diagnosis of OCD, panic disorder with/out agoraphobia (PD) or social anxiety disorder (SAD) in an attempt to address the proposed differentiation of OCD from the other DSM-IV anxiety disorders. Results: Patients with OCD were significantly more likely to have multiple comorbid putative OCSDs than patients with PD or SAD. Some OCSDs, i.e. any tic disorder/Tourette’s disorder as well as body-focused repetitive behaviors (self-injury, trichotillomania), and certain impulsive/reward-focused disorders (kleptomania, hypersexual disorder) were more common in OCD. Some of the putative OCSDs (e.g. hypochondriasis and body dysmorphic disorder) were more common in PD and SAD, respectively. Depression had equally high comorbidity with OCD, PD, and SAD, while generalized anxiety disorder and alcohol dependence were particularly associated with SAD. Conclusions: These findings suggest that some putative OCSDs may be related to OCD, while some may have a closer relationship to other anxiety disorders. From a nosological perspective, it may be useful to include OCD and certain OCSDs under the rubric of an enlarged category of anxiety and OCSDs.
Evaluation of Antidepressant-Like Activity of Novel Water-Soluble Curcumin Formulations and St. John's Wort in Behavioral Paradigms of Despair
Authors: Kulkarni S.K. , Akula Kiran Kumar , Deshpande Jayant
Published: February 2012

Background: Curcumin is the active principle of Curcuma longa, one of the widely used components in the traditional system of medicine in India. Despite its efficacy in experimental studies aiming at neuronal disorders like depression, curcu-min's poor water solubility challenges the production of therapeutic formulations. This study investigates the antidepressant-like activity of novel water-soluble curcumin formulations, dispensed in three different concentrations. Further, the study comparatively evaluates St. John's wort (SJW), another herbal preparation. Methods: These compounds were evaluated in the forced swimming test in mice, and the corresponding changes in the neurotransmitter levels were measured. Results: Three water-soluble curcumin formulations, C-5, C-20 and C-50 (50-200 mg/kg p.o.) decreased the immobility period, and increased serotonin and dopamine levels in the brain tissues. A subeffective dose (50 mg/kg) of these formulations enhanced the antidepressant-like effect of classical antidepressants with varied mechanisms of action. In addition, an SJW dose of 25 mg/kg showed a significant antidepressant-like effect in all the behavioral studies and also significantly increased brain neurotransmitter levels, especially that of serotonin. The effects produced by C-5 were comparable with those of SJW and fluoxetine, respectively. Conclusion: In all these observations, the water-soluble formulations showed a significant antidepressant-like effect, including enhancement of neurotransmitter levels as compared to the similar dose of a conventional curcumin preparation. Thus, these formulations may be used as a novel treatment option in the management of mental depression.
Admission Glucose Does Not Improve GRACE Score at 6 Months and 5 Years after Myocardial Infarction
Authors: de Mulder Maarten , van der Ploeg Tjeerd , de Waard Guus A. , Boersma Eric , Umans Victor A.
Published: February 2012

Objective: Admission plasma glucose (APG) is a biomarker that predicts mortality in myocardial infarction (MI) patients. Therefore, APG may improve risk stratification based on the GRACE risk score. Methods: We collected data on baseline characteristics and long-term (median 55 months) outcome of 550 MI patients who entered our hospital in 2003 and 2006. We determined the GRACE risk score at admission for each patient, which was entered in a logistic regression model, together with APG, to evaluate their prognostic value for 6-month and 5-year mortality. Results: Patients with APG ≧7.8 mmol/l had a higher mortality than those with APG levels <7.8 mmol/l; 6 months: 13.7 versus 3.6%, p value <0.001; 5 years: 20.4 versus 11.1%, p value 0.003. After adjustment for the GRACE risk score variables, APG appeared a significant predictor of 6-month and 5-year mortality, adjusted OR 1.17 (1.06-1.29) and 1.12 (1.03-1.22). The combination of the GRACE risk score and APG increased the model's performance (discrimination C-index 0.87 vs. 0.85), although the difference was not significant (p = 0.095). Combining the GRACE risk score and APG reclassified 12.9% of the patients, but the net reclassification improvement was nonsignificant (p = 0.146). Conclusion: APG is a predictor of 6-month and 5-year mortality, each mmol/l increase in APG being associated with a mortality increase of 17 and 12%, respectively, independent of the GRACE risk score. However, adding APG to the GRACE model did not result in significantly improved clinical risk stratification.
Time Trends in Systemic Thrombolysis in a Large Hospital-Based Stroke Registry
Authors: Singer O.C. , Hamann G.F. , Misselwitz B. , Steinmetz H. , Foerch C. ,   for the Arbeitsgruppe Schlaganfall Hessen
Published: February 2012

Background: Systemic thrombolysis for acute stroke was approved by German authorities in 2002. While recombinant tissue plasminogen activator (rtPA) use first remained low, systemic thrombolysis is nowadays an established part of common stroke care. The purpose of this study was to determine changes in systemic thrombolysis rates within an observation period of 7 years following the approval of rtPA therapy in Germany in a large state-wide stroke data set. Methods: We analyzed a prospective hospital-based stroke registry covering the entire federal state of Hesse, Germany. All hospitals providing stroke care in Hesse (neurology hospitals and hospitals for internal medicine) are obligated to register all inpatients. All cases admitted between 2003 and 2009 with a final diagnosis of ischemic stroke (ICD-10: I63) were selected. We analyzed the relationship between thrombolysis rates, onset-to-admission time (hospital arrival ≤3 and >3 h after symptom onset), patient age (quartiles and dichotomized in ≤80 and >80 years) and disability at admission (assessed by the Rankin Scale). A one-way ANOVA with Bonferroni correction for multiple comparisons was performed to test for significant changes during the observation period. Results: 88,340 patients with ischemic stroke were identified. Thrombolysis rates increased continuously from 2.5% in 2003 to 8.4% in 2009. In patients admitted within 3 h after symptom onset, the thrombolysis rate was 2.5-fold higher in 2009 (25.4%) as compared to 2003 (10.5%). The mean age (±SD) of thrombolyzed patients increased from 68.7 (±11.5) years in 2003 to 70.7 (±13.4) years in 2009 (p for trend = 0.014), but remained stable in the entire cohort. 20.1% of all systemic thrombolytic treatments were performed in patients >80 years old. Disability at admission decreased more pronouncedly in rtPA-treated patients (Rankin Scale score 0-2: 15.2% in 2003 and 24.5% in 2009; p for trend <0.001) as compared to the entire cohort (34.5% in 2003 and 41.5% in 2009; p for trend <0.001). Conclusions: Thrombolytic therapy is increasingly used in acute stroke, particularly in patients admitted within the 3-hour time window. Higher treatment rates are at least partially explained by spreading rtPA application, including older and less severely affected patients. Approximately one fifth of all rtPA treatments were given to the very old (>80 years), which is outside the age limit for rtPA approval. In the light of upcoming demographic changes, the proportion of very aged stroke patients will increase substantially, further tightening the current discussion of an upper age limit for thrombolytic therapy.
CT Angiography of the Aorta Is Superior to Transesophageal Echocardiography for Determining Stroke Subtypes in Patients with Cryptogenic Ischemic Stroke
Authors: Chatzikonstantinou A. , Krissak R. , Flüchter S. , Artemis D. , Schaefer A. , Schoenberg S.O. , Hennerici M.G. , Fink C.
Published: February 2012

Background: The etiology of ischemic strokes remains cryptogenic in about one third of patients, even after extensive workup in specialized centers. Atherosclerotic plaques in the aorta can cause thromboembolic events but are often overlooked. They can elude standard identification by transesophageal echocardiography (TEE), which is invasive or at best uncomfortable for many patients. CT angiography (CTA) can be used as an alternative or in addition to TEE if this technique fails to visualize every part of the aorta and in particular the aortic arch. Methods: We prospectively studied 64 patients (47 men, age 60 ± 13 years) classified as having cryptogenic stroke after standard and full workup [including brain MRI and 24-hour electrocardiogram (ECG)] with ECG-triggered CTA of the aorta in search of plaques and compared the results with those of TEE. Investigators were blinded to the results of both techniques. Plaques were graded on CTA according to their presence (0 = not present; 1 = mild; 2 = severe) and degree of calcification (1a or 2a = noncalcified; 1b or 2b = calcified). Associations with risk factors and infarct localization were also assessed. Results: Only 21 of 64 patients (32.8%) had aortic plaques identified by TEE, compared to 43 of 64 (67.2%) with CTA (p < 0.05). The plaque localization was as follows (TEE vs. CTA): ascending aorta, 10 vs. 20 (p < 0.05); aortic arch, 10 vs. 40 (p < 0.05), and descending aorta, 20 vs. 34 (p < 0.05). Grade 1 plaques were most commonly found in the aortic arch (25; 39%), while grade 2 plaques were most often detected in the aortic arch (15; 23.4%) and the descending aorta (14; 21.9%). There was no significant correlation between plaque location, infarct territory or vascular risk profile, except for hypertension (p = 0.003), which was significantly associated with the presence of plaques. Conclusions: CTA identifies more plaques throughout the aortic arch and around the origins of the major cerebral arteries in particular compared to TEE. These may represent potential embolic sources of acute ischemic stroke. Better plaque detection may have an impact on the best available secondary prevention regimen in individual patients if proximal embolic sources are suspected.
Distinct Dopaminergic Personality Patterns in Patients with Prolactinomas: A Comparison with Nonfunctioning Pituitary Adenoma Patients and Age- and Gender-Matched Controls
Authors: Athanasoulia A.P. , Ising M. , Pfister H. , Mantzoros C.S. , Stalla G.K. , Sievers C.
Published: February 2012

Introduction: Personality patterns such as extraversion and novelty seeking have been associated with an altered dopaminergic activity in healthy subjects. Patients with prolactinomas have been described as exhibiting an altered dopaminergic tone and are often treated with dopamine agonists. Little is known about the personality traits of this patient group. Hence, we aimed at examining whether patients with prolactinomas exhibit modified personality patterns compared to patients with nonfunctioning pituitary adenomas and healthy controls. Subjects/Methods: In this cross-sectional study, 86 patients with prolactinomas and 58 patients with nonfunctioning pituitary adenomas (NFPA) were compared with 172 mentally healthy age- and gender-matched controls. To assess personality traits, standardized personality questionnaires (Eysenck personality questionnaire-EPQ-RK and Tridimensional Personality Questionnaire devised by Cloninger-TPQ) were administered. Results: Patients with either prolactinomas or NFPA showed a distinct personality profile compared to the normal population, characterized by increased neuroticism and they also answered in a socially desirable mode. On harm-avoidant total and subscales, they presented with a higher fear of uncertainty and also increased fatigability and asthenia. The prolactinoma patients, when contrasted with the ‘clinical’ control group of patients with NFPA and after post hoc tests for multiple comparisons following the Bonferroni-Holm procedure showed significantly reduced extraversion (p = 0.044) and increased shyness with strangers (p = 0.044), tending to be more neurotic and present lower scores in the novelty seeking subscale impulsiveness. Conclusion: This is, to our knowledge, the first study providing new evidence of an altered personality profile of prolactinoma patients which might affect the patient-doctor relationship, treatment and patient’s quality of life.
Renal Biopsy in Very Elderly Patients: Data from the Spanish Registry of Glomerulonephritis
Authors: Verde Eduardo , Quiroga Borja , Rivera Francisco , López-Gómez Juan M. ,   on behalf of all the members of the Spanish Registry of Glomerulonephritis
Published: February 2012

Background: Studies on renal histology results in very elderly patients are extremely rare. Methods: We analyzed histology and clinical findings in patients aged over 85 years undergoing renal biopsy and whose data were included in the Spanish Registry of Glomerulonephritis between 1994 and 2009. Results: A total of 17,680 native kidney biopsies were taken: 71 (0.4%) were from patients aged over 85 years. Acute kidney injury (AKI) was the main indication for biopsy (47%), followed by nephrotic syndrome (32%). Amyloidosis was the most common histological diagnosis (16.9%), followed by crescentic glomerulonephritis type 3 associated with systemic vasculitis (14.1%). When histological findings were correlated with clinical syndromes, we found that amyloidosis was the leading cause of AKI (18.8%), and also the main determinant of nephrotic syndrome, with the same frequency as membranous nephropathy (22%). Crescentic glomerulonephritis type 3 associated with vasculitis was related to a greater diversity of clinical syndromes, especially chronic kidney disease (40%) and AKI (40%). Conclusions: Renal biopsy in the very elderly provides us with useful information, despite the advanced age of the patients. AKI and nephrotic syndrome are the main indication for renal biopsy in this subgroup of patients, and amyloidosis is the most frequent histological pattern associated with both syndromes.
Mechanistic View of Risk Factors for Venous Thromboembolism
Authors: Reitsma Pieter H. , Versteeg Henri H. , Middeldorp Saskia
Published: February 2012

Venous thromboembolism is an episodic disease with an annual incidence of 2 to 3/1000 per year that is associated with a high morbidity and mortality. Risk factors for venous thromboembolism come in many guises. They fit into an extended version of Virchow's triad and they tilt the hemostatic balance toward clot formation. This can be achieved by decreasing blood flow and lowering oxygen tension, by activating the endothelium, by activating innate or acquired immune responses, by activating blood platelets, or by increasing the number of platelets and red blood cells or modifying the concentrations of pro- and anticoagulant proteins in the blood. In this narrative review we will discuss the known common risk factors within this pathophysiological framework.
Functional Pace-Mapping Responses for Identification of Targets for Catheter Ablation of Scar-Mediated Ventricular Tachycardia
Authors: Tung Roderick , Mathuria Nilesh , Michowitz Yoav , Yu Ricky , Buch Eric , Bradfield Jason , Mandapati Ravi , Wiener Isaac , Boyle Noel , Shivkumar Kalyanam
Published: February 2012

Background—

Myocardial scars harbor areas of slow conduction and display abnormal electrograms. Pace-mapping at these sites can generate a 12-lead ECG morphological match to a targeted ventricular tachycardia (VT), and in some instances, multiple exit morphologies can result. At times, this can also result in the initiation of VT, termed pace-mapped induction (PMI). We hypothesized that in patients undergoing catheter ablation of VT, scar substrates with multiple exit sites (MES) identified during pace-mapping have improved freedom from recurrent VT, and PMI of VT predicts successful sites of termination during ablation.

Methods and Results—

High-density mapping was performed in all subjects to delineate scar (0.5–1.5 mV). Sites with abnormal electrograms were tagged, stimulated (bipolar 10 mA at 2 ms), and targeted for ablation. MES was defined as >1 QRS morphology from a single pacing site. PMI was defined as initiation of VT during pace-mapping (400–600 ms). In a 2-year period, 44 consecutive patients with scar-mediated VT underwent mapping and ablation. MES were observed during pace-mapping in 25 patients (57%). At 9 months, 74% of patients who exhibited MES during pace-mapping had no recurrence of VT compared with 42% of those without MES observed (
P
=0.024), with an overall freedom from VT of 61%. Thirteen patients (30%) demonstrated PMI, and termination of VT was seen in 95% (18/19) of sites where ablation was performed.

Conclusions—

During pace-mapping, electrograms that exhibit MES and PMI may be specific for sites critical to reentry. These functional responses hold promise for identifying important sites for catheter ablation of VT.
Optical Imaging of Voltage and Calcium in Cardiac Cells & Tissues
Authors: Herron Todd J. , Lee Peter , Jalife José
Published: February 2012

Cardiac optical mapping has proven to be a powerful technology for studying cardiovascular function and disease. The development and scientific impact of this methodology are well-documented. Because of its relevance in cardiac research, this imaging technology advances at a rapid pace. Here, we review technological and scientific developments during the past several years and look toward the future. First, we explore key components of a modern optical mapping set-up, focusing on: (1) new camera technologies; (2) powerful light-emitting-diodes (from ultraviolet to red) for illumination; (3) improved optical filter technology; (4) new synthetic and optogenetic fluorescent probes; (5) optical mapping with motion and contraction; (6) new multiparametric optical mapping techniques; and (7) photon scattering effects in thick tissue preparations. We then look at recent optical mapping studies in single cells, cardiomyocyte monolayers, atria, and whole hearts. Finally, we briefly look into the possible future roles of optical mapping in the development of regenerative cardiac research, cardiac cell therapies, and molecular genetic advances.
Random Assignment within Schools: Lessons Learned from the Teach for America Experiment
Authors: Glazerman Steven
Published: February 2012

Randomized trials are a common way to provide rigorous evidence on the impacts of education programs. This article discusses the trade-offs associated with study designs that involve random assignment of students within schools and describes the experience from one such study of Teach for America (TFA). The TFA experiment faced challenges with recruitment, randomization of students, and analysis. The solutions to those challenges may be instructive for experimenters who wish to study future interventions at the student or classroom level. The article concludes that within-school random assignment studies such as the TFA evaluation are challenging but, under the right conditions, are also feasible and potentially very rewarding in terms of generating useful evidence for policy.
Limitations of Experiments in Education Research
Authors: Schanzenbach Diane Whitmore
Published: February 2012

Research based on randomized experiments (along with high-quality quasi-experiments) has gained traction in education circles in recent years. There is little doubt this has been driven in large part by the shift in research funding strategy by the Department of Education's Institute of Education Sciences under Grover Whitehurst's lead, described in more detail in his article in this issue.
Outgoing Longwave Radiation due to Directly Transmitted Surface Emission
Authors: Costa S. M. S. , Shine K. P.
Published: February 2012

A frequently used diagram summarizing the annual- and global-mean energy budget of the earth and atmosphere indicates that the irradiance reaching the top of the atmosphere from the surface, through the midinfrared atmospheric window, is 40 W m−2; this can be compared to the total outgoing longwave radiation (OLR) of about 235 W m−2. The value of 40 W m−2 was estimated in an ad hoc manner. A more detailed calculation of this component, termed here the surface transmitted irradiance (STI), is presented, using a line-by-line radiation code and 3D climatologies of temperature, humidity, cloudiness, etc. No assumption is made as to the wavelengths at which radiation from the surface can reach the top of the atmosphere. The role of the water vapor continuum is highlighted. In clear skies, if the continuum is excluded, the global- and annual-mean STI is calculated to be about 100 W m−2 with a broad maximum throughout the tropics and subtropics. When the continuum is included, the clear-sky STI is reduced to 66 W m−2, with a distinctly different geographic distribution, with a minimum in the tropics and local peaks over subtropical deserts. The inclusion of clouds reduces the STI to about 22 W m−2. The actual value is likely somewhat smaller due to processes neglected here, and an STI value of 20 W m−2 (with an estimated uncertainty of about ±20%) is suggested to be much more realistic than the previous estimate of 40 W m−2. This indicates that less than one-tenth of the OLR originates directly from the surface.
Ice Growth from the Vapor at −5°C
Authors: Knight Charles A.
Published: February 2012

Results are summarized and illustrated from a long series of experiments on ice growth from the vapor, nearly all in a very small range of conditions: −5°C, slightly below liquid water saturation, with minimal environmental gradients and no imposed ventilation. The temperature was chosen because c-axis ice needles grow in a narrow temperature interval there, which coincides with the temperature at which the Hallett–Mossop ice multiplication process operates most effectively, and one may suspect that this coincidence is likely to be meaningful. The ice growth habit is poorly reproducible in these conditions, dictating many runs with little change. Growth as plates can persist for hours, and two distinct types of needle growth occur, called sheath needles and sharp needles. Both are distinct from thin columns in that they taper to a point, with no discernible basal face. Both deviate slightly from parallel to the c axis. Sharp needles have been reported before, but only as occurring with an applied high DC voltage. New crystal orientations nucleate occasionally at the tips of the sharp needles; this also has been seen before in the presence of strong electric fields. There appears to be an ice multiplication mechanism in these conditions that does not involve riming.
A New Perspective on the Excitation of Low-Tropospheric Mixed Rossby–Gravity Waves in Association with Energy Dispersion
Authors: Chen Guanghua , Tam Chi-Yung
Published: February 2012

This study investigates the synoptic-scale equatorial response to Rossby wave energy dispersion associated with off-equatorial wave activity sources and proposes a new mechanism for triggering low-level mixed Rossby–gravity (MRG) waves. A case study based on observations in boreal summer 2002 reveals that a vortex related to tropical cyclogenesis generated a coherent wave train through southeastward energy dispersion. The southeastward-propagating energy packet gave rise to the equatorial atmospheric response with a temporal scale similar to the wave train and with a structure consistent with the equatorially trapped MRG wave. A baroclinic multilevel anomaly model is employed to verify the excitation of MRG associated with the energy dispersion originating outside of the equatorial region and to explore the discrepancy in the equatorial responses under the different background flows corresponding to El Niño and La Niña. The results show that the prevalence of the low-level westerly flow, the associated zonal wind convergence, and the easterly vertical wind shear can be more favorable for the enhancement of southeastward-propagating energy dispersion and equatorial MRG response in the low troposphere during El Niño than those during La Niña. In addition, the strength of the mean flow can strongly affect the extent of equatorial wave response and modulate its phase and group velocity due to the Doppler shift effect.