bluuebunny/crossref_metadata_2025 huggingface dataset:
Catch My Drift?
Authors: Rubin Elihu
Published: September 2012

Each fall and spring, the author asks his students to dérive, to engage in the Situationist practice of “drift” — a short definition might be to wander on foot without itinerary. The dérive is introduced as the third research method in a series that explores social meanings within built environments. This essay reflects on five years of assigning the dérive and parses students' reactions to and representations of that experience. The author contextualizes the dérive as a critique of postwar urban planning and as a distinct form of walking as urban experience. Finally, he speculates on the possibilities of the dérive as a tool for urban research. “Drifting” is hard to do because it requires active disorientation, an untethering from what grounds us. Yet there is utility in this endeavor — to awaken our senses, but also to disturb received sociospatial relationships and to inscribe new and broader terrains of urban inclusivity.
Walking the Elastic City: Total Detroit
Authors: Miller Hillary
Published: September 2012

Elastic City, an organization that gives sensory, conceptual walks through New York City, explores embodied approaches to accessing urban archives. Todd Shalom, the artistic director of the organization, invites artists to create walks that emphasize engagement with the city space not through observation and exchange of factual information, but through participatory performances. Every Elastic City event positions walking as a central practice that awakens participants to their own mental mapping process while also maintaining a careful attention to the street as lived space. In August 2011, theater director Niegel Smith led Total Detroit, a walk that encompassed fifty-seven hours, beginning and ending at LaGuardia Airport. As a performance, Total Detroit rehearsed Smith's ideas about walking and social meaning. This interview with Shalom and Smith was conducted one week after they had returned from Total Detroit.
Pelvic congestion syndrome diagnosed using endoscopic ultrasonography
Authors: Cho S J , Lee T H , Shim K Y , Hong S S , Goo D E
Published: September 2012

Pelvic congestion syndrome (PCS) presents with a non-cyclic pelvic pain lasting more than six months in duration in premenopausal women. Pelvic ultrasonography or computed tomography is usually the first imaging modality used to evaluate patients with suspected PCS. PCS is confirmed by visible congestion of the pelvic veins on selective ovarian venography. To our knowledge, the role of endoscopic ultrasonography (EUS) has not been reported. EUS showed multiple dilated structures especially on left side around the uterus and ovaries, which are compatible with other radiological investigations of PCS Although PCS is not typical areas within the scope of practice of endosonographers, it is useful to be familiar with the findings. We report a case of PCS that was diagnosed with the aid of EUS.
Perceived Versus Actual Sedation Practices in Adult Intensive Care Unit Patients Receiving Mechanical Ventilation
Authors: Gill Kimberly Varney , Voils Stacy A , Chenault Gregory A , Brophy Gretchen M
Published: September 2012

Background:

With drug shortages, newer sedative medications, and updates in research, management of sedation and delirium in patients receiving mechanical ventilation continues to evolve.

Objective:

To compare perceived and actual sedation practices for adults receiving mechanical ventilation in intensive care units (ICUs).

Methods:

This was a multicenter, 2-part study conducted in adult ICUs in US hospitals, It included a sedation practice survey completed by ICU pharmacists and an observational study evaluating actual sedation practices over a 24-hour period.

Results:

Surveys were completed for 85 ICUs; observational data for 496 patients were collected. Preferred sedatives from the survey data were propofol (short-term); propofol, midazolam, or lorazepam (intermediate); and lorazepam (long-term). Propofol was the most commonly used agent overall during the observational period (primarily for short-term and intermediate-length sedation); midazolam was the most commonly used for long-term sedation. Fentanyl was the preferred analgesic, and Haloperidol and quetiapine were the preferred antipsychotics. Sedation treatment algorithms were used in only 50% of observed ICUs. Use of daily interruption of sedation was perceived to be 66% but was only observed in 36% of patients. Monitoring for delirium was reported among 25% of those surveyed but was observed in only 10% of patients. Targeted sedation goals were most frequently achieved when a treatment algorithm was used or when an opiate infusion was the single agent used for sedative management

Conclusions:

These data suggest differences in perceived and actual sedation practice in the US, as well as underutilization of evidence-based interventions. Most notable was the limited use of sedation treatment algorithms, daily interruption of sedation, and monitoring for delirium. Individual sedation and delirium protocols should be evaluated and updated based on evidence-based recommendations.
Treatment of Levator Ani Syndrome with Cyclobenzaprine
Authors: Sheikh Maheen , Kunka Crystal A , Ota Ken S
Published: September 2012

Objective

TO report a case of levator ani syndrome (LAS) that was successfully treated with cyclobenzaprine.

Case Summary

A 26-year-old male presented with a 3-week history of severe, intermittent, aching anorectal pain that would last for 30–60 minutes per episode and occurred between 1 and 3 times per day. The pain was aggravated by squatting, with no alleviating factors. Physical examination revealed no prostate tenderness, lesions, hemorrhoids, or fissures and rectal tone was intact. The patient had moderate posterior rectal tenderness. After a standard workup, he was diagnosed with LAS and treated with oral cyclobenzaprine 5 mg 3 times daily for 7 days. The patient experienced resolution of his symptoms after 3 days of treatment and remained symptom-free 6 months after completion of therapy. The only reported adverse effect was mild drowsiness, which resolved after discontinuation of the cyclobenzaprine.

Discussion

A review of the literature via StatRef (April 1965-December 2011), Ovid (April 1965-December 2011), and MEDLINE (April 1965-December 2011) reveals that existing treatment options for LAS have been limited to levator massage, sitz baths, nonsteroidal antiinflammatory drugs, diazepam, biofeedback, botulinum toxin, steroid injections, and electrogalvanic stimulation, all of which offer minimal support. Cyclobenzaprine is a muscle relaxant; however, its mechanism of action is unclear. It is thought to influence the α and γ motor neurons in the central nervous system, which leads to the attenuation of muscle spasm. To our knowledge, cyclobenzaprine has not been reported as a treatment for LAS. In our patient, however, the clinical efficacy of cyclobenzaprine was clearly apparent.

Conclusions

Cyclobenzaprine effectively treated our patient's LAS. Given that cyclobenzaprine is safe, inexpensive, and shown to be effective in our case study, we believe it warrants further investigation as a first-line treatment option for LAS.
Effect of drying on the color of St. John’s wort (Hypericum perforatum L.) leaves
Authors: Chenarbon Hossein Ahmadi , Minaei Saeid , Bassiri Ali Reza , Almassi Morteza , Arabhosseini Akbar , Motevali Ali
Published: September 2012

The effect of drying on color changes of St. John’s wort (Hypericum perforatum L.) leaves was investigated. The samples were dried at drying air temperatures of 40, 50, 60, and 70°C, air velocities of 0.3, 0.7, and 1 m/s and bed depths of 1, 2, and 3cm with factorial experimental design based on completely randomized design. All treatments were tested in three replications. The total color difference (ΔE) and saturation index or chroma (SI) was evaluated as the important quality parameters. The Duncan’s multiple range tests was used to compare the treatment means. Regarding to SI and ΔE indices the most suitable quality was found for the samples dried at temperature of 40°C, air velocity of 0.3 m/s and bed depth of 3 cm.
Human epididymis protein 4 as a serum marker for diagnosis of endometrial carcinoma and prediction of clinical outcome
Authors: Zanotti Laura , Bignotti Eliana , Calza Stefano , Bandiera Elisabetta , Ruggeri Giuseppina , Galli Claudio , Tognon Germana , Ragnoli Monica , Romani Chiara , Tassi Renata A. , Caimi Luigi , Odicino Franco E. , Sartori Enrico , Pecorelli Sergio , Ravaggi Antonella
Published: September 2012

Background: The purpose of this study was to assess the diagnostic and prognostic impact of preoperative serum determination of human epididymis protein 4 (sHE4), and to investigate its potential correlation with clinicopathological features and survival endpoints in endometrial cancer patients.

Methods: Preoperative serum samples from 193 endometrial cancer patients and 125 women with normal endometrium were measured for sHE4 and serum CA125 (sCA125) concentrations by quantitative chemiluminescent microparticle immunoassays on the automated Architect instrument.

Results: sHE4 concentrations were significantly higher in endometrial cancer patients regardless of tumour stage and grade compared with normal controls. Setting the specificity at 95%, the sensitivities in detecting endometrial cancer patients were 66% for HE4, 33% for CA125 and 64% for the combination of the two markers. High concentrations of both HE4 and CA125 significantly correlated with all clinicopathological features characterising a more aggressive tumour phenotype. In multivariate analysis, only high preoperative sHE4 concentrations, but not sCA125, were independent prognostic factors for shorter Overall Survival, Disease-Free Survival and Progression-Free Survival.

Conclusions: HE4 is more sensitive and specific than CA125 in distinguishing endometrial cancer patients from women with normal endometrium, regardless of tumour stage and grade. sHE4 appears to be associated with a more aggressive tumour variant and it could be clinically useful, in identifying high-risk endometrial cancer patients, for a tailored surgical and postoperative therapy. HE4 significant correlation with decreased Overall Survival, Disease Free Survival and Progression Free Survival suggests its potential role as a novel prognostic marker for endometrial cancer.
Revaluating serum ferritin as a marker of body iron stores in the traceability era
Authors: Ferraro Simona , Mozzi Roberta , Panteghini Mauro
Published: September 2012

Serum ferritin is used for diagnosing iron-related disorders. However, most studies validating this application were performed before the introduction of the 2nd and 3rd WHO International Standards (ISs) to harmonize assay results. We revised the available literature to evaluate if consolidated clinical applications of ferritin and recommended cut-offs have been validated using ISs calibrated assays. All Medline retrieved reviews and individual studies performed since ISs availability were selected and analyzed according to predefined criteria. Concerning ferritin and iron deficiency (ID), only one review, including studies published before 1988, met established criteria. Results showed that ferritin can effectively rule out ID anemia in patients with or without inflammatory disease at cut-offs of 70 and 40 μg/L, respectively. From two studies using ISs calibrated assays that met inclusion criteria, no information emerged on which cut-off should be employed to obtain similar sensitivity. Regarding iron overload, even when the framework was restricted to hereditary hemochromatosis, no synthesis of scientific evidence, if any, about diagnostic accuracy of ferritin was available both before and after ISs introduction. Available evidence of the ferritin diagnostic effectiveness is limited to ID conditions. Recommended cut-offs for this application are, however, based on studies published from 1970 to the 1980s using non-harmonized assays.
A corpus-based look at short turns in university classroom interaction
Authors: Csomay, Eniko
Published: September 2012

The aim of the present study is to explore the lexical content of short turns in university classroom discourse. Corpus-based techniques were applied to identify a large number of turns to analyze their lexical content in over two hundred university class sessions. The findings show that, although students take sixty per cent of the turns in our university classrooms, they use only twenty per cent of the total number of words. Consequently, students would produce short turns most of the times while teachers would engage in longer stretches of talk. The results also indicate that short turns generally mark intensive interactional sequences. More specifically, a closer look at the lexical items in these short turns and the functions they serve clearly show that while teachers offer support, elicit further elaboration or prompt reformulation, students mostly indicate agreement, understanding and involvement with these short turns. Considering the turn as a unit of analysis and its characteristic features such as turn-length and lexical variation, the findings of the lexical analysis of short turns suggest that participant roles can be well-defined in the classroom context.
Twin-to-twin transfusion syndrome and limb ischemia: a case report
Authors: Hollander Richard Alexander , Puylaert Dirk , Fabry Kristof , Debeer Anne , Lewi Liesbeth , Van de Broek Hilde
Published: September 2012

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies. This condition is associated with high mortality if untreated. Treatment consists of either serial reduction of amniotic fluid or selective laser photocoagulation (SLP). In utero limb ischemia is a known complication of TTTS. An interaction between this condition and SLP has never been established. Here, we describe the first of twins born at 34 weeks’ gestational age, delivered by emergency cesarean section for fetal distress after a pregnancy complicated by severe TTTS. The first twin, the recipient in the TTTS, showed a necrotic right limb, which was amputated above the knee joint on the 23rd day of life. Anatomic-pathological investigation revealed vascular thrombosis. The foot-length was compatible with a gestational age of 16–18 weeks, the time of limb ischemia, which is well before 26 weeks, when SLP was performed. Therefore, we refute that the fetal limb ischemia was a complication of SLP.
Hyperreactio luteinalis in a spontaneously conceived pregnancy associated with polycystic ovarian syndrome and high levels of human chorionic gonadotropin
Authors: Kyvernitakis Ioannis , Ziller Volker , Hadji Peyman , Wagner Uwe , Schmidt Stephan , Arabin Birgit
Published: September 2012

Aim: To report a case of hyperreactio luteinalis in a spontaneously conceived pregnancy.

Patient: A 29-year-old primigravida presenting with painful multicystic ovarian lesions.

Methods: Laparotomy and reconstruction of the ovaries.

Main outcome measures: Successful pregnancy and delivery of a 3650 g female infant at 39 weeks, without any abnormalities.

Results: Highly elevated human chorionic gonadotropin, estradiol, progesterone, testosterone, and free testosterone levels were observed. Ultrasound revealed bilaterally enlarged multicystic ovaries with several cysts of up to 9 cm in diameter.

Conclusions: In this case, laparotomy appeared to be an appropriate therapy to prevent further suffering in the mother without doing harm to the fetus.
Industrial Silicon Wafer Solar Cells – Status and Trends
Authors: Armin G. Aberle , Matthew B. Boreland , Bram Hoex , Thomas Mueller
Published: September 2012

Crystalline silicon solar cells dominate today's global photovoltaic (PV) market. This paper presents the status and trends of the most important industrial silicon wafer solar cells, ranging from standard p-type homojunction cells to heterojunction cells on n-type wafers. Owing to ongoing technological innovations such as improved surface passivation and the use of increasingly thinner wafers, the trend towards higher cell efficiencies and lower $/watt costs is expected to continue during the next 10 years, making silicon wafer based PV modules a moving target for any competing PV technology.
PV Module Technology and Reliability – Status and Perspectives
Authors: Harry Wirth , Claudio Ferrara
Published: September 2012

Solar cell processing into modules is mostly responsible for the product's reliability, has a severe impact on product costs and controls 10–15% of its efficiency. This article gives an overview on current module technology and highlights innovative approaches to reduce material cost and increase module efficiency. High potential approaches like back contact technology are those that simultaneously address cell and module technology to offer efficiency gains in the range of 10%.

Module reliability expectations of 25 years or more require quality assurance beyond the common type approval standards. In its second part, the article addresses stress factors for PV modules. To ensure fast innovation cycles, accelerated aging tests are used to reproduce these stress factors in the laboratory. Results from certification testing are discussed as well as new approaches for improved testing. More realistic test results can be obtained by simulating combinations of stress factors.
Light Trapping Concepts for Photon Management in Solar Cells
Authors: Sprafke A. N. , Wehrspohn R. B.
Published: September 2012

Photon management is a key component in the development of efficient solar cells. Especially light-trapping concepts have a high potential to realize enhanced efficiencies. Here, we give an overview over several light trapping concepts for photon management in solar cells. These include basic as well as advanced light-trapping concepts. The theoretical limits of light path enhancement of the different concepts are given and experimental work on these topics is presented. The potential of 3D photonic crystals is discussed in the context of the corresponding approaches as well.
Steam pretreatment for enzymatic hydrolysis of poplar wood: comparison of optimal conditions with and without SO2 impregnation
Authors: Schütt Fokko , Haas Nils Peter , Dehne Laura , Koch Gerald , Janzon Ron , Saake Bodo
Published: September 2012

Steam refining of non-debarked poplar wood with SO2 impregnation prior to steaming was investigated as pretreatment for enzymatic hydrolysis. Pretreatment conditions were varied in the range of 170°C–220°C, 3–30 min and 0.7–2.5% SO2 according to a factorial design. Predicted steaming conditions for highest carbohydrate yields after enzymatic hydrolysis were at 200°C, 15 min, and 2.5% SO2. The yield of glucose and xylose from control tests under these conditions was 43% representing an increase of 9% compared to results of former experiments without SO2 impregnation. Investigations on lignin extracted from the fibers revealed no distinct differences between pretreatment with and without SO2. No sulfonation occurred by the impregnation with SO2. Topochemical analyses of the fibers by cellular UV microspectrophotometry (UMSP) showed an inhomogeneous lignin distribution within the S2 of fibers after pretreatment without SO2 and local depositions of high UV-absorbing substances in the lumina of fibers and parenchyma cells. The lignin distribution of fiber cell walls after pretreatment with SO2 was more homogeneous with a preserved fiber network and only little amounts of deposited phenolic compounds in the lumina. Therefore, it might be concluded that the expulsion of lignin hinders the enzymes in accessing the cellulose.
Experimental and numerical analysis of the sound insulation property of wood plastic composites (WPCs) filled with precipitated CaCO3
Authors: Li Peng , Kim Birm-June , Wang Qingwen , Wu Qinglin
Published: September 2012

The sound transmission loss (STL) of precipitated calcium carbonate (PCC)-filled wood plastic composite (WPC) was studied using a numerical analysis method based on the mass law and sound scattering theory. Several physical models for explaining sound wave transmission in WPC were established, and relevant STL equations were derived. The STL of WPC filled with different PCC weight ratios was analyzed using these models. The results showed that the STL of WPC increased with an increase in sound frequency and PCC weight ratio. The improvement of sound insulation was attributed to the mass increase, sound scattering enhancement by the fillers, and PCC weight ratio. The predicted results showed similar trends to the experimental data under the same processing conditions. It was concluded that the proposed models can be used to analyze the STL of filled WPC. Larger inorganic particle size led to higher STL, but its effect was not obvious at lower frequency ranges. Predicted STL increased with increased weight ratio of wood for the whole frequency range tested.
Clinical evaluation of soluble intercellular adhesion molecule-1 and insulin like growth factor-binding protein-1-based rapid immunoassays for the diagnosis of prelabor rupture of membranes
Authors: Wang Tao , Zhou Rong , Xiong Wei , Wang Yanyun , Zhu Cairong , Song Changping , Gao Linbo , Zhang Lin , Hu Huaizhong
Published: September 2012

Aims: To evaluate the clinical value of two rapid tests, based on soluble intercellular adhesion molecule-1 (Leakection) and insulinlike growth factor-binding protein-1 (Amnioquick), for the diagnosis of prelabor rupture of membranes.

Methods: A total of 200 pregnant women were recruited in this study: 100 pregnant women with membrane rupture and 100 healthy pregnant women as controls. Patients and controls were randomly divided into Leakection and Amnioquick groups, respectively. Sensitivity and specificity were calculated on the basis of the detection results.

Results: For the 100 women tested with Leakection, the sensitivity and specificity was 94% and 96%, respectively; the total accuracy was 95%. For the 100 women tested with Amnioquick, the sensitivity and specificity was 80% and 100%, respectively; the total accuracy was 90%.

Conclusions: Both Leakection and Amnioquick are non-invasive and inexpensive rapid tests for the diagnosis of premature or prelabor rupture of membranes with high sensitivity and specificity. These tests could greatly help the timely diagnosis of premature or prelabor rupture of membranes in clinical practice.
Tailoring nanostructured catalysts for electrochemical energy conversion systems
Authors: Gago Aldo S. , Habrioux Aurelien , Alonso-Vante Nicolas
Published: September 2012

This review covers topics related to the synthesis of nanoparticles, the anodic and cathodic electrochemical reactions and low temperature electrochemical energy devices. The thermodynamic aspects of nucleation and growth of nanoparticles are discussed. Different methods of chemical synthesis such as w/o microemulsion, Bönnemann, polyol and carbonyl are presented. How the electrochemical reactions take place on the surface of the catalytic nanoparticles and the importance of the substrate is put in evidence. The use of nanomaterials in low temperature energy devices such as H2/O2 polymer electrolyte or proton exchange membrane fuel cell (PEMFC) and micro-direct methanol fuel cell (μDMFC), as well as recent progress and durability, is discussed. Special attention is given to the novel laminar flow fuel cell (LFFC). This review starts with the genesis of catalytic nanoparticles, continues with the surface electrochemical reactions that occur on them, and finally it discusses their application in electrochemical energy devices such as low temperature fuel cells or Li-air batteries.
MSK1 Regulates Homeostatic and Experience-Dependent Synaptic Plasticity
Authors: Corrêa Sonia A. L. , Hunter Christopher J. , Palygin Oleg , Wauters Sandrine C. , Martin Kirsty J. , McKenzie Colin , McKelvey Kim , Morris Richard G. M. , Pankratov Yuriy , Arthur J. Simon C. , Frenguelli Bruno G.
Published: September 2012

The ability of neurons to modulate synaptic strength underpins synaptic plasticity, learning and memory, and adaptation to sensory experience. Despite the importance of synaptic adaptation in directing, reinforcing, and revising the behavioral response to environmental influences, the cellular and molecular mechanisms underlying synaptic adaptation are far from clear. Brain-derived neurotrophic factor (BDNF) is a prime initiator of structural and functional synaptic adaptation. However, the signaling cascade activated by BDNF to initiate these adaptive changes has not been elucidated. We have previously shown that BDNF activates mitogen- and stress-activated kinase 1 (MSK1), which regulates gene transcription via the phosphorylation of both CREB and histone H3. Using mice with a kinase-dead knock-in mutation of MSK1, we now show that MSK1 is necessary for the upregulation of synaptic strength in response to environmental enrichmentin vivo. Furthermore, neurons from MSK1 kinase-dead mice failed to show scaling of synaptic transmission in response to activity deprivationin vitro, a deficit that could be rescued by reintroduction of wild-type MSK1. We also show that MSK1 forms part of a BDNF- and MAPK-dependent signaling cascade required for homeostatic synaptic scaling, which likely resides in the ability of MSK1 to regulate cell surface GluA1 expression via the induction of Arc/Arg3.1. These results demonstrate that MSK1 is an integral part of a signaling pathway that underlies the adaptive response to synaptic and environmental experience. MSK1 may thus act as a key homeostat in the activity- and experience-dependent regulation of synaptic strength.
Neurobiological Mechanisms Underlying the Blocking Effect in Aversive Learning
Authors: Eippert Falk , Gamer Matthias , Büchel Christian
Published: September 2012

Current theories of classical conditioning assume that learning depends on the predictive relationship between events, not just on their temporal contiguity. Here we employ the classic experiment substantiating this reasoning—the blocking paradigm—in combination with functional magnetic resonance imaging (fMRI) to investigate whether human amygdala responses in aversive learning conform to these assumptions. In accordance with blocking, we demonstrate that significantly stronger behavioral and amygdala responses are evoked by conditioned stimuli that are predictive of the unconditioned stimulus than by conditioned stimuli that have received the same pairing with the unconditioned stimulus, yet have no predictive value. When studying the development of this effect, we not only observed that it was related to the strength of previous conditioned responses, but also that predictive compared with nonpredictive conditioned stimuli received more overt attention, as measured by fMRI-concurrent eye tracking, and that this went along with enhanced amygdala responses. We furthermore observed that prefrontal regions play a role in the development of the blocking effect: ventromedial prefrontal cortex (subgenual anterior cingulate) only exhibited responses when conditioned stimuli had to be established as nonpredictive for an outcome, whereas dorsolateral prefrontal cortex also showed responses when conditioned stimuli had to be established as predictive. Most importantly, dorsolateral prefrontal cortex connectivity to amygdala flexibly switched between positive and negative coupling, depending on the requirements posed by predictive relationships. Together, our findings highlight the role of predictive value in explaining amygdala responses and identify mechanisms that shape these responses in human fear conditioning.
Learning and Memory Deficits Consequent to Reduction of the Fragile X Mental Retardation Protein Result from Metabotropic Glutamate Receptor-Mediated Inhibition of cAMP Signaling inDrosophila
Authors: Kanellopoulos Alexandros K. , Semelidou Ourania , Kotini Andriana G. , Anezaki Maria , Skoulakis Efthimios M. C.
Published: September 2012

Loss of the RNA-binding fragile X protein [fragile X mental retardation protein (FMRP)] results in a spectrum of cognitive deficits, the fragile X syndrome (FXS), while aging individuals with decreased protein levels present with a subset of these symptoms and tremor. The broad range of behavioral deficits likely reflects the ubiquitous distribution and multiple functions of the protein. FMRP loss is expected to affect multiple neuronal proteins and intracellular signaling pathways, whose identity and interactions are essential in understanding and ameliorating FXS symptoms. We used heterozygous mutants and targeted RNA interference-mediated abrogation inDrosophilato uncover molecular pathways affected by FMRP reduction. We present evidence that FMRP loss results in excess metabotropic glutamate receptor (mGluR) activity, attributable at least in part to elevation of the protein in affected neurons. Using high-resolution behavioral, genetic, and biochemical analyses, we present evidence that excess mGluR upon FMRP attenuation is linked to the cAMP decrement reported in patients and models, and underlies olfactory associative learning and memory deficits. Furthermore, our data indicate positive transcriptional regulation of the flyfmr1gene by cAMP, via protein kinase A, likely through the transcription factor CREB. Because the human Fmr1 gene also contains CREB binding sites, the interaction of mGluR excess and cAMP signaling defects we present suggests novel combinatorial pharmaceutical approaches to symptom amelioration upon FMRP attenuation.
The Relationship between Working Memory Storage and Elevated Activity as Measured with Functional Magnetic Resonance Imaging
Authors: Riggall Adam C. , Postle Bradley R.
Published: September 2012

Does the sustained, elevated neural activity observed during working memory tasks reflect the short-term retention of information? Functional magnetic resonance imaging (fMRI) data of delayed recognition of visual motion in human participants were analyzed with two methods: a general linear model (GLM) and multivoxel pattern analysis. Although the GLM identified sustained, elevated delay-period activity in superior and lateral frontal cortex and in intraparietal sulcus, pattern classifiers were unable to recover trial-specific stimulus information from these delay-active regions. The converse—no sustained, elevated delay-period activity but successful classification of trial-specific stimulus information—was true of posterior visual regions, including area MT+ (which contains both middle temporal area and medial superior temporal area) and calcarine and pericalcarine cortex. In contrast to stimulus information, pattern classifiers were able to extract trial-specific task instruction-related information from frontal and parietal areas showing elevated delay-period activity. Thus, the elevated delay-period activity that is measured with fMRI may reflect processes other than the storage, per se, of trial-specific stimulus information. It may be that the short-term storage of stimulus information is represented in patterns of (statistically) “subthreshold” activity distributed across regions of low-level sensory cortex that univariate methods cannot detect.
Loss of Retinoschisin (RS1) Cell Surface Protein in Maturing Mouse Rod Photoreceptors Elevates the Luminance Threshold for Light-Driven Translocation of Transducin But Not Arrestin
Authors: Ziccardi Lucia , Vijayasarathy Camasamudram , Bush Ronald A. , Sieving Paul A.
Published: September 2012

Loss of retinoschisin (RS1) inRs1knock-out (Rs1–KO) retina produces a post-photoreceptor phenotype similar to X-linked retinoschisis in young males. However,Rs1is expressed strongly in photoreceptors, andRs1–KO mice have early reduction in the electroretinogram a-wave. We examined light-activated transducin and arrestin translocation in youngRs1–KO mice as a marker for functional abnormalities in maturing rod photoreceptors. We found a progressive reduction in luminance threshold for transducin translocation in wild-type (WT) retinas between postnatal days P18 and P60. At P21, the threshold inRs1–KO retinas was 10-fold higher than WT, but it decreased to <2.5-fold higher by P60. Light-activated arrestin translocation and re-translocation of transducin in the dark were not affected.Rs1–KO rod outer segment (ROS) length was significantly shorter than WT at P21 but was comparable with WT at P60. These findings suggested a delay in the structural and functional maturation ofRs1–KO ROS. Consistent with this, transcription factors CRX and NRL, which are fundamental to maturation of rod protein expression, were reduced in ROS ofRs1–KO mice at P21 but not at P60. Expression of transducin was 15–30% lower in P21Rs1–KO ROS and transducin GTPase hydrolysis was nearly twofold faster, reflecting a 1.7- to 2.5-fold increase in RGS9 (regulator of G-protein signaling) level. Transduction protein expression and activity levels were similar to WT at P60. Transducin translocation threshold elevation indicates photoreceptor functional abnormalities in youngRs1–KO mice. Rapid reduction in threshold coupled with age-related changes in transduction protein levels and transcription factor expression are consistent with delayed maturation ofRs1–KO photoreceptors.
A Unilateral Negative Feedback Loop BetweenmiR-200microRNAs and Sox2/E2F3 Controls Neural Progenitor Cell-Cycle Exit and Differentiation
Authors: Peng Changgeng , Li Na , Ng Yen-Kar , Zhang Jingzhong , Meier Florian , Theis Fabian J. , Merkenschlager Matthias , Chen Wei , Wurst Wolfgang , Prakash Nilima
Published: September 2012

MicroRNAs have emerged as key posttranscriptional regulators of gene expression during vertebrate development. We show that themiR-200family plays a crucial role for the proper generation and survival of ventral neuronal populations in the murine midbrain/hindbrain region, including midbrain dopaminergic neurons, by directly targeting the pluripotency factor Sox2 and the cell-cycle regulator E2F3 in neural stem/progenitor cells. The lack of a negative regulation of Sox2 and E2F3 bymiR-200in conditionalDicer1mutants (En1+/Cre;Dicer1flox/floxmice) and aftermiR-200knockdownin vitroleads to a strongly reduced cell-cycle exit and neuronal differentiation of ventral midbrain/hindbrain (vMH) neural progenitors, whereas the opposite effect is seen aftermiR-200overexpression in primary vMH cells. Expression ofmiR-200is in turn directly regulated by Sox2 and E2F3, thereby establishing a unilateral negative feedback loop required for the cell-cycle exit and neuronal differentiation of neural stem/progenitor cells. Our findings suggest that the posttranscriptional regulation of Sox2 and E2F3 bymiR-200family members might be a general mechanism to control the transition from a pluripotent/multipotent stem/progenitor cell to a postmitotic and more differentiated cell.
PrPCHomodimerization Stimulates the Production of PrPCCleaved Fragments PrPN1 and PrPC1
Authors: Béland Maxime , Motard Julie , Barbarin Alice , Roucou Xavier
Published: September 2012

An endoproteolytic cleavage termed α-cleavage between residues 111/112 is a characteristic feature of the cellular prion protein (PrPC). This cleavage generates a soluble N-terminal fragment (PrPN1) and a glycosylphosphatidylinositol-anchored C-terminal fragment (PrPC1). Independent studies demonstrate that modulating PrPCα-cleavage represents a potential therapeutic strategy in prion diseases. The regulation of PrPCα-cleavage is unclear. The only known domain that is essential for the α-cleavage to occur is a hydrophobic domain (HD). Importantly, the HD is also essential for the formation of PrPChomodimers. To explore the role of PrPChomodimerization on the α-cleavage, we used a well described inducible dimerization strategy whereby a chimeric PrPCcomposed of a modified FK506-binding protein (Fv) fused with PrPCand termed Fv-PrP is incubated in the presence of a dimerizer AP20187 ligand. We show that homodimerization leads to a considerable increase of PrPCα-cleavage in cultured cells and release of PrPN1 and PrPC1. Interestingly, enforced homodimerization increased PrPClevels at the plasma membrane, and preventing PrPCtrafficking to the cell surface inhibited dimerization-induced α-cleavage. These observations were confirmed in primary hippocampal neurons from transgenic mice expressing Fv-PrP. The proteases responsible for the α-cleavage are still elusive, and in contrast to initial studies we confirm more recent investigations that neither ADAM10 nor ADAM17 are involved. Importantly, PrPN1 produced after PrPChomodimerization protects against toxic amyloid-β (Aβ) oligomers. Thus, our results show that PrPChomodimerization is an important regulator of PrPCα-cleavage and may represent a potential therapeutic avenue against Aβ toxicity in Alzheimer's disease.
Peripheral Ammonia as a Mediator of Methamphetamine Neurotoxicity
Authors: Halpin Laura E. , Yamamoto Bryan K.
Published: September 2012

Ammonia is metabolized by the liver and has established neurological effects. The current study examined the possibility that ammonia contributes to the neurotoxic effects of methamphetamine (METH). The results show that a binge dosing regimen of METH to the rat increased plasma and brain ammonia concentrations that were paralleled by evidence of hepatotoxicity. The role of peripheral ammonia in the neurotoxic effects of METH was further substantiated by the demonstration that the enhancement of peripheral ammonia excretion blocked the increases in brain and plasma ammonia and attenuated the long-term depletions of dopamine and serotonin typically produced by METH. Conversely, the localized perfusion of ammonia in combination with METH, but not METH alone or ammonia alone, into the striatum recapitulated the neuronal damage produced by the systemic administration of METH. Furthermore, this damage produced by the local administration of ammonia and METH was blocked by the GYKI 52466 [4-(8-methyl-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepin-5-yl)-benzamine hydrochloride], an AMPA receptor antagonist. These findings highlight the importance of ammonia derived from the periphery as a small-molecule mediator of METH neurotoxicity and more broadly emphasize the importance of peripheral organ damage as a possible mechanism that mediates the neuropathology produced by drugs of abuse and other neuroactive molecules.
Disruption of Dentate Gyrus Blocks Effect of Visual Input on Spatial Firing of CA1 Neurons
Authors: Lee Jong Won , Kim Woon Ryoung , Sun Woong , Jung Min Whan
Published: September 2012

The role of dentate gyrus in hippocampal mnemonic processing is uncertain. One proposed role of dentate gyrus is binding internally generated spatial representation with sensory information on external landmarks. To test this hypothesis, we compared effects of visual input on spatial firing of CA1 neurons inBaxknock-out mice in which dentate gyrus neural circuitry is selectively disrupted. Whereas spatial selectivity of CA1 neuronal firing was significantly higher under normal illumination than complete darkness in wild-type mice, it was similarly low in both illumination conditions inBaxknock-out mice. Also, whereas the spatial location of neuronal firing was more stably maintained in the light than in the dark condition in wild-type mice, it was similarly unstable in both illumination conditions inBaxknock-out mice. These results show that visual input allows selective and stable spatial firing of CA1 neurons in normal animals, but this effect is lost if dentate gyrus neural circuitry is disrupted. Our results provide empirical support for the proposed role of dentate gyrus in aligning internally generated spatial representation to external landmarks in building a unified representation of external space.
Dependence of Regenerated Sensory Axons on Continuous Neurotrophin-3 Delivery
Authors: Hou Shaoping , Nicholson LaShae , van Niekerk Erna , Motsch Melanie , Blesch Armin
Published: September 2012

Previous studies have shown that injured dorsal column sensory axons extend across a spinal cord lesion site if axons are guided by a gradient of neurotrophin-3 (NT-3) rostral to the lesion. Here we examined whether continuous NT-3 delivery is necessary to sustain regenerated axons in the injured spinal cord. Using tetracycline-regulated (tet-off) lentiviral gene delivery, NT-3 expression was tightly controlled by doxycycline administration. To examine axon growth responses to regulated NT-3 expression, adult rats underwent a C3 dorsal funiculus lesion. The lesion site was filled with bone marrow stromal cells, tet-off-NT-3 virus was injected rostral to the lesion site, and the intrinsic growth capacity of sensory neurons was activated by a conditioning lesion. When NT-3 gene expression was turned on, cholera toxin β-subunit-labeled sensory axons regenerated into and beyond the lesion/graft site. Surprisingly, the number of regenerated axons significantly declined when NT-3 expression was turned off, whereas continued NT-3 expression sustained regenerated axons. Quantification of axon numbers beyond the lesion demonstrated a significant decline of axon growth in animals with transient NT-3 expression, only some axons that had regenerated over longer distance were sustained. Regenerated axons were located in white matter and did not form axodendritic synapses but expressed presynaptic markers when closely associated with NG2-labeled cells. A decline in axon density was also observed within cellular grafts after NT-3 expression was turned off possibly via reduction in L1 and laminin expression in Schwann cells. Thus, multiple mechanisms underlie the inability of transient NT-3 expression to fully sustain regenerated sensory axons.
Crystal structure of catena-[dichlorido-μ2-4,4’-dithiodipyridine-κ2N:N’- zinc(II)], C10H8Cl2N2S2Zn
Authors: Seidel Rüdiger W. , Dietz Christina , Oppel Iris M.
Published: September 2012

C10H8Cl2N2S2Zn, monoclinic, C2/c (no. 15), a = 12.317(2) Å, b = 9.868(2) Å, c = 10.947(2) Å, β = 92.37(2)°, V = 1329.3 Å3, Z = 4, Rgt(F) = 0.036, wRref(F2) = 0.132, T = 110 K.
The role of adipokines in β-cell failure of type 2 diabetes
Authors: Dunmore Simon J , Brown James E P
Published: September 2012

β-Cell failure coupled with insulin resistance is a key factor in the development of type 2 diabetes. Changes in circulating levels of adipokines, factors released from adipose tissue, form a significant link between excessive adiposity in obesity and both aforementioned factors. In this review, we consider the published evidence for the role of individual adipokines on the function, proliferation, death and failure of β-cells, focusing on those reported to have the most significant effects (leptin, adiponectin, tumour necrosis factor α, resistin, visfatin, dipeptidyl peptidase IV and apelin). It is apparent that some adipokines have beneficial effects whereas others have detrimental properties; the overall contribution to β-cell failure of changed concentrations of adipokines in the blood of obese pre-diabetic subjects will be highly dependent on the balance between these effects and the interactions between the adipokines, which act on the β-cell via a number of intersecting intracellular signalling pathways. We emphasise the importance, and comparative dearth, of studies into the combined effects of adipokines on β-cells.
Molecular characterization of virulence factors in Aeromonas hydrophila obtained from fish
Authors: Oliveira Samira T.L. , Veneroni-Gouveia Gisele , Costa Mateus M.
Published: September 2012

Multiple factors can be involved in the virulence processes of Aeromonas hydrophila. The objective of the present paper was to verify the presence of aerolysin, hidrolipase, elastase and lipase virulence genes through the polymerase chain reaction (PCR) in A. hydrophila isolates obtained from fish of the São Francisco River Valley, and to evaluate virulence according to the presence of these genes in Nile tilapia fingerlings. One hundred and fourteen isolates from the bacteria were used. DNA was heat extracted and PCR undertaken using specific primers described in the literature. For in vivo tests Nile tilapia fingerlings were used. From the PCR tests, negative isolates for all genes tested were selected, positive isolates for two genes (aerolysin and elastase) and positive for the four genes tested. These were inoculated at a concentration of 10(8) UFC/ml into the tilapias, considered as treatments; another group of animals was used as control (with inoculation of saline solution). In all, 12 distinct standards regarding the presence of virulence factors in isolates from A. hydrophila, were observed. Of the 114 isolates analyzed, 100 (87.72%) presented at least one of the virulence factors under study. The virulence factors were widely distributed among the A. hydrophila isolates. Aerolysin was the most frequent virulence factor present in the isolates analyzed. A. hydrophila led to the mortality of the Nile tilapia fingerlings, regardless of the absence or quantity of virulence genes tested.
Nested-PCR for the detection of Mycoplasma hyopneumoniae in bronchial alveolar swabs, frozen tissues and formalin-fixed paraffin-embedded swine lung samples: comparative evaluation with immunohistochemical findings and histological features
Authors: Almeida Paula R. , Andrade Caroline P. , Almeida Laura L. , Oliveira Luiz G.S. , Castro Luiza A. , Zlotowski Priscila , Silva Sérgio C. da , Driemeier David
Published: September 2012

The diagnosis of Mycoplasma hyopneumoniae infection is often performed through histopathology, immunohistochemistry (IHC) and polymerase chain reaction (PCR) or a combination of these techniques. PCR can be performed on samples using several conservation methods, including swabs, frozen tissue or formalin-fixed and paraffin-embedded (FFPE) tissue. However, the formalin fixation process often inhibits DNA amplification. To evaluate whether M. hyopneumoniae DNA could be recovered from FFPE tissues, 15 lungs with cranioventral consolidation lesions were collected in a slaughterhouse from swine bred in herds with respiratory disease. Bronchial swabs and fresh lung tissue were collected, and a fragment of the corresponding lung section was placed in neutral buffered formalin for 48 hours. A PCR assay was performed to compare FFPE tissue samples with samples that were only refrigerated (bronchial swabs) or frozen (tissue pieces). M. hyopneumoniae was detected by PCR in all 15 samples of the swab and frozen tissue, while it was detected in only 11 of the 15 FFPE samples. Histological features of M. hyopneumoniae infection were presented in 11 cases and 7 of these samples stained positive in IHC. Concordance between the histological features and detection results was observed in 13 of the FFPE tissue samples. PCR was the most sensitive technique. Comparison of different sample conservation methods indicated that it is possible to detect M. hyopneumoniae from FFPE tissue. It is important to conduct further research using archived material because the efficiency of PCR could be compromised under these conditions.