bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescent ribonucleoside analogues as probes for investigating RNA structure and function
Authors: Srivatsan Seergazhi G. , Sawant Anupam A.
Published: December 2010

Numerous biophysical tools based on fluorescence have been developed to advance the understanding of RNA–nucleic acid, RNA–protein, and RNA–small molecule inter-actions. In this regard, fluorescent ribonucleoside analogues that are sensitive to their local environment provide sensitive probes for investigating RNA structure, dynamics, and recognition. Most of these analogues closely resemble the native ribonucleosides with respect to their overall dimension and have the ability to form canonical Watson–Crick (WC) base pairs. Therefore, it is possible to place these probes near the point of interaction in a target nucleic acid with minimum structural perturbations and gain insight into the intricacies of conformational changes taking place in and around the interaction site. Here, we provide a concise background on the development and recent advances in the applications of base-modified fluorescent ribonucleoside analogue probes. We first present various base-modified fluorescent ribonucleoside analogues, their photophysical properties, and methods to incorporate these analogues into oligoribonucleotides. We then discuss the established spectroscopic techniques, which make use of the fluorescence properties of these emissive ribonucleoside analogues. Finally, we present the applications of base-modified fluorescent ribonucleoside analogues used as probes incorporated into oligoribonucleotides in investigating RNA structures and functions.
Spectral Insight into Intensity Variations in Phase-Transition Processes Using Two-Dimensional Correlation Analysis
Authors: Wang Mengyin , Sun Shengtong , Wu Peiyi
Published: December 2010

Two-dimensional correlation spectroscopy (2D-COS) is widely used in studies of phase-transition processes to provide valuable order information that is useful in investigating these mechanisms. During phase-transition processes, the spectral intensity always changes in an “S”- or “anti-S”-shaped curve. Sample selection of the large and complicated dataset for 2D correlation analysis may impact the resulting sequence and should be given serious consideration. Additionally, the relationship between the sequential order obtained from 2D-COS and the parameters of the intensity change, namely, the transition point and the change rate, is still poorly defined. This article makes an attempt to resolve these problems based on the analysis of simulated spectra by assuming that the band intensity changes in a sigmoid manner without a step delay. It is concluded that the sample range around a transition point with a drastic intensity change defined by asynchronous perturbation-correlation moving-window (PCMW2D) analysis is a reasonable choice, and in this region a band that changes earlier as determined by 2D-COS most likely has an earlier phase-transition point. Also, from the results of segmental analysis, it is proposed that 2D-COS can distinguish the sequence of two bands using only rate difference; however, the rate difference and the form of the intensity change should be considered comprehensively. The insights from the simulated results are applied to analyze the temperature-dependent infrared (IR) spectra of poly[di(butyl)vinylterephthalate] (PDBVT). The phase-transition mechanism of PDBVT can be clearly found using a suitable sample selection method.
Two-Dimensional Attenuated Total Reflection Infrared Correlation Spectroscopy Study of the Desorption Process of Water-Soaked Cotton Fibers
Authors: Liu Yongliang , Gamble Gary , Thibodeaux Devron
Published: December 2010

Two-dimensional (2D) correlation analysis was applied to characterize the attenuated total reflection (ATR) spectral intensity fluctuations of native cotton fibers with various water contents. Prior to 2D analysis, the spectra were leveled to zero at the peak intensity of 1800 cm−1 and then were normalized at the peak intensity of 660 cm−1 to subjectively correct the changes resulting from water diffusion in fibers and resultant density dilution. Next, a new spectral set was subjected to principal component analysis (PCA) and two clusters of hydrated (≥13.3%) and dehydrated (<13.3%) fibers were obtained. Synchronous and asynchronous 2D correlation spectra from individual ATR spectral sets enhanced spectral resolution and provided insights about water-content-dependent intensity variations not readily accessible from one-dimensional ATR spectra. The 2D results revealed remarkable differences corresponding to water loss between the hydrated and dehydrated fibers. Of interest were that: (1) the intensity of the 1640 cm−1 water band remains in a steady state for hydrated fibers but decreases for dehydrated fibers; (2) during the desorption process of adsorbed water, small and water-soluble carbonyl species (i.e., esters, acids, carboxylates, and proteins) begin to accumulate on the cotton surface, resulting in possible changes in the coloration and surface chemistry of native cotton fibers that were rained on prior to harvesting; (3) intensities of bands in the 1200 to 950 cm−1 region exhibit a more apparent intensity increase than those in the 1500 to 1200 cm−1 region, indicating the sensitivity of the 1200 to 950 cm−1 infrared (IR) region to intra- and inter-molecular hydrogen bonding in fiber celluloses; and (4) the 750 cm−1 band, ascribed to the unstable Iα phase in amorphous regions, might originate from the cellulose–water complex through hydrogen bonding.
InSb Focal Plane Array Chemical Imaging Enables Assessment of Unit Process Efficiency for Milling Operation
Authors: Wetzel David L. , Posner Elieser S. , Dogan Hulya
Published: December 2010

In the dry milling of wheat flour, each unit process (roller mill, purifier, sifter, etc.) produces a mixture with varying amounts of wheat endosperm and non-endosperm byproducts. Chemical images with 82000 pixels of each intermediate product stream issuing from an individual processing machine are readily analyzed in terms of the relative amount of endosperm and non-endosperm. Approximately three minutes is required to produce an image of each intermediate product stream. Applying partial least squares (PLS) chemometric software to identify individual pixels, which enables calculation of the relative amount of endosperm and non-endosperm, is not a time-limiting factor. When relative flow rates are known for each stream, mass balance can be calculated from each intermediate stream in terms of the product (endosperm content) and the lower value non-endosperm byproduct. Data is presented from a purifier in a commercial flour mill. Intermediate streams collected from a run with optimized operational parameters were compared to those of another run before adjustment. The endosperm (product) mass balance profile for each run enabled assessment of operational efficiency. The devised chemical imaging analysis system would be particularly useful in commissioning of a new mill or to optimize existing wheat milling systems. Also, when raw material differs from that for which previous optimization was established, a new optimization may be in order. The ability to acquire a large number of spectra from a specimen and apply multivariate statistics to identify each pixel and subsequently count pixels accommodates heterogeneity and reports the results from averaging a very large number of individual spectra. A second illustration of the utility of the imaging method is presented centering on streams from the first and second break unit operations at the beginning of the roller mill process.
Ultra: A Unique Instrument for Time-Resolved Spectroscopy
Authors: Greetham Gregory M. , Burgos Pierre , Cao Qian , Clark Ian P. , Codd Peter S. , Farrow Richard C. , George Michael W. , Kogimtzis Moschos , Matousek Pavel , Parker Anthony W. , Pollard Mark R. , Robinson David A. , Xin Zhi-Jun , Towrie Michael
Published: December 2010

We report the development of a high-sensitivity time-resolved infrared and Raman spectrometer with exceptional experimental flexibility based on a 10-kHz synchronized dual-arm femtosecond and picosecond laser system. Ultrafast high-average-power titanium sapphire lasers and optical parametric amplifiers provide wavelength tuning from the ultraviolet (UV) to the mid-infrared region. Customized silicon, indium gallium arsenide, and mercury cadmium telluride linear array detectors are provided to monitor the probe laser intensity in the UV to mid-infrared wavelength range capable of measuring changes in sample absorbance of ΔOD ∼ 10−5 in 1 second. The system performance is demonstrated for the time-resolved infrared, two-dimensional (2D) infrared, and femtosecond stimulated Raman spectroscopy techniques with organometallic intermediates, organic excited states, and the dynamics of the tertiary structure of DNA.
Determination of Time-Dependent Protoporphyrin IX Concentration for Photodynamic Therapy Dosimetry in a Mice Colon Tumor Model Using Fluorescence Spectroscopy
Authors: Naghavi Nadia , Baygi Mohammad Hossein Miran , Sazgarnia Ameneh
Published: December 2010

Photodynamic therapy (PDT) is an effective treatment method for various types of invasive tumors. The efficiency of PDT treatment depends, to a great extent, on optimal dosimetry of light, the photosensitizer used, and on tissue oxygenation. Fluorescence spectroscopy can be employed for measurement of drug concentration in target tissue and can provide a basis for in vivo evaluation of treatment efficiency. We have developed an integrated system that can be used to determine photosensitizer concentration in vivo based on fluorescence measurements. In our study, we performed fluorescence measurements on colon tumors of Balb/c mice in which CT26 cells were injected subcutaneously in the right flank. 5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was used as the photosensitizer. ALA was administered intraperitoneally at a dose of 200 mg/kg and PpIX fluorescence profiles were followed up to 34 h after ALA administration. Maximum fluorescence intensity was found 8 h after ALA administration. Also, we determined the relationship between PpIX concentration in colon tumor tissue of Balb/c mice and its fluorescence intensity at the peak of the spectrum (635 nm). This was used to determine the PpIX content in the target tissue as a function of time after ALA administration.
Increasing Research Familiarity Among Members of a Clubhouse for People With Mental Illness
Authors: Marshall Sarah Louise , Deane Frank , Hancock Nicola
Published: December 2010

This study describes a project that aimed to train people with mental illness in introductory research skills to support the development of a Clubhouse. Eight mental health consumers from the Illawarra region in New South Wales, Australia were recruited to participate in the project. The group met weekly over a 10-week period to participate in training sessions. The training program focused on increasing familiarity and confidence with research related activities considered useful for Clubhouse members. Measures related to Familiarity with the Clubhouse model, Clubhouse Role Confidence, Research Self Efficacy, and Familiarity with Research Terminology were completed by six of eight participants before and after training. There were significant improvements in consumer's familiarity with components of the Clubhouse and research terminology. There was also increased confidence in performing roles relevant to research activities in Clubhouse settings but no significant improvements in Research Self efficacy related to more general research skills. There is a need for future research to confirm the findings in larger trials with a control condition.
Analysing the Expert Judgment of a Rehabilitation Counsellor: A Case Study
Authors: Athanasou James A. , Kaufmann Esther
Published: December 2010

This case study analysed the expert judgments of a rehabilitation counsellor. The counsellor was given 37 accident victims' self-ratings of health, energy, daily activities, self-esteem, personal relations, financial resources and living conditions. The accident victims also rated their own overall quality of life as poor or good. The expert was required to make judgments about whether the quality of life was poor or good in each case and matched the ratings of the accident victims in 64.8% of cases. The results suggest that under conditions of uncertainty and complexity an expert may be more accurate than chance but still fail to use the properties of information to their maximum advantage.
Impacts of Uncertainty of Progressive Disability on Life Perspectives
Authors: Chen Roy K. , Miller Eva , Seo Wonsun (Sunny) , Mendoza Eliana
Published: December 2010

The present study examined ways in which progressive disability affects the pursuit of personal goals and how the uncertainty of progressive disability influences life perspectives. A total of 117 individuals with muscular dystrophy responded to two open-ended questions designed to elicit their views on the psychological and behavioural manifestations of progressive disability. Specifically, the study used a three-step phenomenological existential approach to analyse the written responses by the participants (Creswell, 2009). The results indicated that factors such as involuntary early retirement, problems establishing and maintaining romantic relationships; changing personal and career goals, fear of uncertainties, feeling undesirable and unattractive, lack of accessible transportation, and fear of passing on hereditary diseases affect an individual's psychological well-being. The need for around-the-clock care can present a burden that leads to caregiver burnout and resentment. Implications for rehabilitation professionals are provided based upon review of the literature and qualitative data analysis.
A novel liquidchip platform for simultaneous detection of 70 alleles of DNA somatic mutations on EGFR, KRAS, BRAF and PIK3CA from formalin-fixed and paraffin-embedded slides containing tumor tissue
Authors: Li Guoqiang , Luo Xiaodi , He Jiaying , Zhu Zeyao , Yu Gang , Qin Huijuan , Zeng Tao , Liu Zhiming , Wu Shiyang , Xu Jiasen , Ren-Heidenreich Lifen
Published: December 2010

Background: DNA somatic mutations of EGFR, KRAS, BRAF and PIK3CA in the epidermal growth factor receptor (EGFR) signaling pathway play critical roles in the response or resistance of tumors to targeted therapy with tyrosine kinase inhibitors (EGFR-TKIs). To provide a high-throughput (HTP) clinical testing service for detecting these mutations, we developed a novel platform, SurPlex

®
-xTAG70plex-EGFR liquidchip.

Methods: This platform was developed based on a universal 100-tag system. The procedures for multiplex PCR, allele specific primer extension (ASPE) and hybridization were optimized and standardized.

Results: A total of 70 alleles of somatic mutations of EGFR, KRAS, BRAF and PIK3CA can be detected simultaneously in one reaction from one formalin-fixed and paraffin-embedded (FFPE) slide within one day. Cross-reaction was <8% between individual amplimers and 70 different ASPE primers. The sensitivity for detecting mutants in the wild-type DNA was 1%–5%. Seventy-three FFPE samples with somatic mutations were used to validate the 70plex. Seventy-one showed a complete match, while two were not detected.

Conclusions: A simple, accurate, sensitive HTP technology was developed and standardized for detecting simultaneously 70 different alleles of EGFR, KRAS, BRAF and PIK3CA gene mutations from FFPE tumor slides.
Impact of cryopreservation on serum concentration of matrix metalloproteinases (MMP)-7, TIMP-1, vascular growth factors (VEGF) and VEGF-R2 in Biobank samples
Authors: Kisand Kalle , Kerna Irina , Kumm Jaanika , Jonsson Helgi , Tamm Agu
Published: December 2010

Background: Blood biomarkers are subject to pre-analytical variability. In many cases, the stability of important new tissue biomarkers during freeze cycles and storage has not been studied sufficiently.

Methods: To test the stability of matrix metalloproteinases-7 (MMP-7) and their tissue inhibitors (TIMP-1), vascular growth factors (VEGF) and VEGF-receptor, serum samples were frozen and then thawed up to six times. The impact of storage temperature was investigated using an accelerated stability testing protocol. Stability at –20°C and –75°C was calculated using the Arrhenius equation.

Results: The average concentration of TIMP-1 was stable, even after six freeze/thaw cycles. One thawing did not change the concentration of MMP-7 and VEGF-receptor. However, repeated freeze/thaw cycles increased the measured values significantly. Decreases in VEGF concentrations were dramatic, even after the first freeze/thaw cycle. According to the Arrhenius calculation, MMP-7 showed excellent stability, at least 5 years at –20°C and several 100 years at –75°C. The VEGF-receptor maintains 90% of its initial concentration at –20°C over 3 months, and decades at –75°C. TIMP-1 and VEGF showed poor stability with cryopreservation, even at –75°C.

Conclusions: The stability of MMP-7, TIMP-1, VEGF or VEGF-receptor in biobanking is highly variable, and this should be taken into account in the interpretation of results. A temperature –20°C is unsuitable for prolonged storage of the biomarkers investigated, and repeated thawing of sera is not recommended. VEGF is especially unstable and should be quantitated using serum that has never been frozen.
Boundedly generated subgroups of finite groups
Authors: Lucchini Andrea , Morigi Marta , Shumyatsky Pavel
Published: December 2010

The starting point for this work was the question whether every finite group G contains a two-generated subgroup H such that , where denotes the set of primes dividing the order of G. We answer the question in the affirmative and address the following more general problem.
Let G be a finite group and let be a property of G. What is the minimum number t such that G contains a t-generated subgroup H satisfying the condition that ? In particular, we consider the situation where is the set of composition factors (up to isomorphism), the exponent, the prime graph, or the spectrum of the group G. We give a complete answer in the cases where is the prime graph or the spectrum (obtaining that in the former case and t can be arbitrarily large in the latter case). We also prove that if is the exponent of G, then t is at most four.
Anterior Cingulate Synapses in Prefrontal Areas 10 and 46 Suggest Differential Influence in Cognitive Control
Authors: Medalla Maria , Barbas Helen
Published: December 2010

Dorsolateral prefrontal areas 46 and 10 are involved in distinct aspects of cognition. Area 46 has a key role in working memory tasks, and frontopolar area 10 is recruited in complex multitask operations. Both areas are innervated by the anterior cingulate cortex (ACC), a region associated with emotions and memory but is also important for attentional control through unknown synaptic mechanisms. Here, we found that in rhesus monkeys (Macaca mulatta) most axon terminals labeled from tracers injected into ACC area 32 innervated spines of presumed excitatory neurons, but ∼20–30% formed mostly large synapses with dendritic shafts of presumed inhibitory neurons in the upper layers (I–IIIa) of dorsolateral areas 10, 46, and 9. Moreover, area 32 terminals targeted preferentially calbindin and, to a lesser extent, calretinin neurons, which are thought to be inhibitory neurons that modulate the gain of task-relevant activity during working memory tasks. Area 46 was distinguished as a recipient of more (by ∼40%) area 32 synapses on putative inhibitory neurons. Area 10 stood apart as recipient of significantly larger (by ∼40% in volume) area 32 terminals on spines of putative excitatory neurons. These synaptic specializations suggest that area 32 has complementary roles, potentially enhancing inhibition in area 46 and strengthening excitation in area 10, which may help direct attention to new tasks while temporarily holding in memory another task.
Caloric Restriction Experience Reprograms Stress and Orexigenic Pathways and Promotes Binge Eating
Authors: Pankevich Diana E. , Teegarden Sarah L. , Hedin Andrew D. , Jensen Catherine L. , Bale Tracy L.
Published: December 2010

Long-term weight management by dieting has a high failure rate. Pharmacological targets have focused on appetite reduction, although less is understood as to the potential contributions of the stress state during dieting in long-term behavioral modification. In a mouse model of moderate caloric restriction in which a 10–15% weight loss similar to human dieting is produced, we examined physiological and behavioral stress measures. After 3 weeks of restriction, mice showed significant increases in immobile time in a tail suspension test and stress-induced corticosterone levels. Increased stress was associated with brain region-specific alterations of corticotropin-releasing factor expression and promoter methylation, changes that were not normalized with refeeding. Similar outcomes were produced by high-fat diet withdrawal, an additional component of human dieting. In examination of long-term behavioral consequences, previously restricted mice showed a significant increase in binge eating of a palatable high-fat food during stress exposure. Orexigenic hormones, melanin-concentrating hormone (MCH) and orexin, were significantly elevated in response to the high-fat diet only in previously restricted mice. Furthermore, administration of the MCH receptor-1 antagonist GSK-856464 [4-(4-ethyl-5-methylsulfanyl-1,2,4-triazol-3-yl)pyridine] significantly reduced total caloric intake in these mice during high-fat access. These results reveal reprogramming of key central pathways involved in regulating stress responsivity and orexigenic drives by moderate caloric restriction experience. In humans, such changes would be expected to reduce treatment success by promoting behaviors resulting in weight regain, and suggest that management of stress during dieting may be beneficial in long-term maintenance.
Anterior Insula Integrates Information about Salience into Perceptual Decisions about Pain
Authors: Wiech Katja , Lin Chia-shu , Brodersen Kay H. , Bingel Ulrike , Ploner Markus , Tracey Irene
Published: December 2010

The decision as to whether a sensation is perceived as painful does not only depend on sensory input but also on the significance of the stimulus. Here, we show that the degree to which an impending stimulus is interpreted as threatening biases perceptual decisions about pain and that this bias toward pain manifests before stimulus encounter. Using functional magnetic resonance imaging we investigated the neural mechanisms underlying the influence of an experimental manipulation of threat on the perception of laser stimuli as painful. In a near-threshold pain detection paradigm, physically identical stimuli were applied under the participants' assumption that the stimulation is entirely safe (low threat) or potentially harmful (high threat). As hypothesized, significantly more stimuli were rated as painful in the high threat condition. This context-dependent classification of a stimulus as painful was predicted by the prestimulus signal level in the anterior insula, suggesting that this structure integrates information about the significance of a stimulus into the decision about pain. The anticipation of pain increased the prestimulus functional connectivity between the anterior insula and the midcingulate cortex (MCC), a region that was significantly more active during stimulation the more a participant was biased to rate the stimulation as painful under high threat. These findings provide evidence that the anterior insula and MCC as a “salience network” integrate information about the significance of an impending stimulation into perceptual decision-making in the context of pain.
Modulation of BK Channel Gating by the β2 Subunit Involves Both Membrane-Spanning and Cytoplasmic Domains of Slo1
Authors: Lee Urvi S. , Shi Jingyi , Cui Jianmin
Published: December 2010

Large-conductance, Ca2+- and voltage-sensitive K+(BK) channels regulate neuronal functions such as spike frequency adaptation and transmitter release. BK channels are composed of four Slo1 subunits, which contain the voltage-sensing and pore-gate domains in the membrane and Ca2+binding sites in the cytoplasmic domain, and accessory β subunits. Four types of BK channel β subunits (β1–β4) show differential tissue distribution and unique functional modulation, resulting in diverse phenotypes of BK channels. Previous studies show that both the β1 and β2 subunits increase Ca2+sensitivity, but different mechanisms may underline these modulations. However, the structural domains in Slo1 that are critical for Ca2+-dependent activation and targeted by these β subunits are not known. Here, we report that the N termini of both the transmembrane (including S0) and cytoplasmic domains of Slo1 are critical for β2 modulation based on the study of differential effects of the β2 subunit on two orthologs, mouse Slo1 andDrosophilaSlo1. The N terminus of the cytoplasmic domain of Slo1, including the AC region (βA–αC) of the RCK1 (regulator of K+conductance) domain and the peptide linking it to S6, both of which have been shown previously to mediate the coupling between Ca2+binding and channel opening, is specifically required for the β2 but not for the β1 modulation. These results suggest that the β2 subunit modulates the coupling between Ca2+binding and channel opening, and, although sharing structural homology, the BK channel β subunits interact with structural domains in the Slo1 subunit differently to enhance channel activity.
Bax Regulates Production of Superoxide in Both Apoptotic and Nonapoptotic Neurons: Role of Caspases
Authors: Kirkland Rebecca A. , Saavedra Geraldine M. , Cummings Brian S. , Franklin James L.
Published: December 2010

A Bax- and, apparently, mitochondria-dependent increase in superoxide (O2·−) and other reactive oxygen species (ROS) occurs in apoptotic superior cervical ganglion (SCG) and cerebellar granule (CG) neurons. Here we show that Bax also lies upstream of ROS produced in nonapoptotic neurons and present evidence that caspases partially mediate the pro-oxidant effect of Bax. We used the O2·−-sensitive dye MitoSOX to monitor O2·−in neurons expressing different levels of Bax and mitochondrial superoxide dismutase (SOD2). Basal and apoptotic O2·−levels in both SCG and CG neurons were reduced in SOD2 wild-type (WT) cells having lower Bax concentrations. Apoptotic and nonapoptotic neurons from Bax-WT/SOD2-null but not Bax-null/SOD2-null mice had increased O2·−levels. A caspase inhibitor inhibited O2·−in both apoptotic and nonapoptotic SCG neurons. O2·−production increased when WT, but not Bax-null, SCG neurons were permeabilized and treated with active caspase 3. There was no apoptosis and little increase in O2·−in SCG neurons from caspase 3-null mice exposed to an apoptotic stimulus. O2·−levels in nonapoptotic caspase 3-null SCG neurons were lower than in WT cells but not as low as in caspase inhibitor-treated cells. These data indicate that Bax lies upstream of most O2·−produced in neurons, that caspase 3 is required for increased O2·−production during neuronal apoptosis, that caspase 3 is partially involved in O2·−production in nonapoptotic neurons, and that other caspases may also be involved in Bax-dependent O2·−production in nonapoptotic cells.
Phosphorylation Promotes Neurotoxicity in aCaenorhabditis elegansModel of TDP-43 Proteinopathy
Authors: Liachko Nicole F. , Guthrie Chris R. , Kraemer Brian C.
Published: December 2010

Neurodegenerative disorders characterized by neuronal and glial lesions containing aggregated pathological TDP-43 protein in the cytoplasm, nucleus, or neurites are collectively referred to as TDP-43 proteinopathies. Lesions containing aggregated TDP-43 protein are a hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-U). In addition, mutations in human TDP-43 cause ALS. We have developed aCaenorhabditis elegansmodel of TDP-43 proteinopathies to study the cellular, molecular, and genetic underpinnings of TDP-43-mediated neurotoxicity. Expression of normal human TDP-43 in allC. elegansneurons causes moderate motor defects, whereas ALS-mutant G290A, A315T, or M337V TDP-43 transgenes cause severe motor dysfunction. The model recapitulates some characteristic features of ALS and FTLD-U including age-induced decline in motor function, decreased life span, and degeneration of motor neurons accompanied by hyperphosphorylation, truncation, and ubiquitination of TDP-43 protein that accumulates in detergent-insoluble protein deposits. InC. elegans, TDP-43 neurotoxicity is independent of activity of the cell death caspase CED-3. Furthermore, phosphorylation of TDP-43 at serine residues 409/410 drives mutant TDP-43 toxicity. This model provides a tractable system for additional dissection of the cellular and molecular mechanisms underlying TDP-43 neuropathology.
NG2 Glia Generate New Oligodendrocytes But Few Astrocytes in a Murine Experimental Autoimmune Encephalomyelitis Model of Demyelinating Disease
Authors: Tripathi Richa B. , Rivers Leanne E. , Young Kaylene M. , Jamen Francoise , Richardson William D.
Published: December 2010

The adult mammalian brain and spinal cord contain glial precursors that express platelet-derived growth factor receptor α subunit (PDGFRA) and the NG2 proteoglycan. These “NG2 cells” descend from oligodendrocyte precursors in the perinatal CNS and continue to generate myelinating oligodendrocytes in the gray and white matter of the postnatal brain. It has been proposed that NG2 cells can also generate reactive astrocytes at sites of CNS injury or demyelination. To test this we examined the fates of PDGFRA/NG2 cells in the mouse spinal cord during experimental autoimmune encephalomyelitis (EAE)—a demyelinating condition that models some aspects of multiple sclerosis in humans. We administered tamoxifen toPdgfra-CreERT2:Rosa26R-YFPmice to induce yellow fluorescent protein (YFP) expression in PDGFRA/NG2 cells and their differentiated progeny. We subsequently induced EAE and observed a large (>4-fold) increase in the local density of YFP+cells, >90% of which were oligodendrocyte lineage cells. Many of these became CC1-positive, NG2-negative differentiated oligodendrocytes that expressed myelin markers CNP and Tmem10/Opalin. PDGFRA/NG2 cells generated very few GFAP+-reactive astrocytes (1–2% of all YFP+cells) or NeuN+neurons (<0.02%). Thus, PDGFRA/NG2 cells act predominantly as a reservoir of new oligodendrocytes in the demyelinated spinal cord.
Emergence of Lamina-Specific Retinal Ganglion Cell Connectivity by Axon Arbor Retraction and Synapse Elimination
Authors: Cheng Ting-Wen , Liu Xiao-Bo , Faulkner Regina L. , Stephan Alexander H. , Barres Ben A. , Huberman Andrew D. , Cheng Hwai-Jong
Published: December 2010

Throughout the nervous system, neurons restrict their connections to specific depths or “layers” of their targets to constrain the type and number of synapses they make. Despite the importance of lamina-specific synaptic connectivity, the mechanisms that give rise to this feature in mammals remain poorly understood. Here we examined the cellular events underlying the formation of lamina-specific retinal ganglion cell (RGC) axonal projections to the superior colliculus (SC) of the mouse. By combining a genetically encoded marker of a defined RGC subtype (OFF-αRGCs) with serial immunoelectron microscopy, we resolved the ultrastructure of axon terminals fated for laminar stabilization versus those fated for removal. We found that OFF-αRGCs form synapses across the full depth of the retinorecipient SC before undergoing lamina-specific arbor retraction and synapse elimination to arrive at their mature, restricted pattern of connectivity. Interestingly, we did not observe evidence of axon degeneration or glia-induced synapse engulfment during this process. These findings indicate that lamina-specific visual connections are generated through the selective stabilization of correctly targeted axon arbors and suggest that the decision to maintain or eliminate an axonal projection reflects the molecular compatibility of presynaptic and postsynaptic neurons at a given laminar depth.
The Sympathetic Neurotransmitter Switch Depends on the Nuclear Matrix Protein Satb2
Authors: Apostolova Galina , Loy Bernhard , Dorn Roland , Dechant Georg
Published: December 2010

Sympathetic neurons can switch their neurotransmitter phenotype from noradrenergic to cholinergic on exposure to neuropoietic cytokinesin vitroandin vivo. Here, we provide evidence that this transspecification is regulated by the chromatin architecture protein Satb2. Treatment with the neuropoietic cytokines ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor rapidly and strongly increases Satb2 transcript and protein levels in cultures of rat superior cervical ganglia neurons. Knockdown of endogenous Satb2 by short interfering RNA prevents the upregulation of choline acetyltransferase (Chat) and vesicular acetylcholine transporter (Vacht) by CNTF as well as the loss of norepinephrine transporter (Net). Conversely, overexpression of Satb2 in the noradrenergic sympathetic phenotype results in a marked increase of Chat and Vacht expression and reduced Net mRNA levels in the absence of neuropoietic cytokines. Chromatin immunoprecipitation analysis in primary sympathetic neurons reveals that Satb2 binds to matrix attachment regions (MARs) within the Chat locus.In vivo, in the rat stellate ganglion, Satb2 is expressed exclusively in sudomotor cholinergic neurons innervating the sweat glands and only after establishment of contact between neurons and target. These findings demonstrate a function of the MAR-binding protein Satb2 in growth factor-dependent neurotransmitter plasticity in postmitotic neurons.
Differential Cone Pathway Influence on Intrinsically Photosensitive Retinal Ganglion Cell Subtypes
Authors: Schmidt Tiffany M. , Kofuji Paulo
Published: December 2010

A small subset of ganglion cells in the mammalian retina express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). These cells are the primary conduits through which photic information is relayed to non-image-forming visual centers that mediate behaviors such as the pupillary light reflex and circadian entrainment. M1 and M2 cells comprise distinct morphological subpopulations of ipRGC, and possess physiological diversity in their intrinsic membrane properties and intrinsic light responses. Additionally, evidence now indicates that all ipRGCs receive photic information from rods/cones via synaptic signaling. It has recently been reported that Off-stratifying M1 cells paradoxically receive input from the On pathway within the Off sublamina of the inner plexiform layer. The purpose of the current study was to examine the functional consequences of cone pathway signaling to M1 and M2 cells. Using pharmacological tools and single-cell recordings of synaptic responses in wild-type and melanopsin-null mice, we found that the On pathway forms the primary excitatory synaptic input to both M1 and M2 cells. This input was much more influential in shaping the light-evoked responses and resting membrane properties of M2 cells than M1 cells. These findings indicate a surprising differential reliance upon cone-mediated phototransduction by ipRGC subpopulations. These findings also suggest that ipRGC subtypes signal diverse photic information to various non-image-forming visual centers.
Lithium Ameliorates Nucleus Accumbens Phase-Signaling Dysfunction in a Genetic Mouse Model of Mania
Authors: Dzirasa Kafui , Coque Laurent , Sidor Michelle M. , Kumar Sunil , Dancy Elizabeth A. , Takahashi Joseph S. , McClung Colleen A. , Nicolelis Miguel A. L.
Published: December 2010

Polymorphisms in circadian genes such as CLOCK convey risk for bipolar disorder. While studies have begun to elucidate the molecular mechanism whereby disruption ofClockalters cellular function within mesolimbic brain regions, little remains known about how these changes alter gross neural circuit function and generate mania-like behaviors inClock-Δ19 mice. Here we show that the phasic entrainment of nucleus accumbens (NAC) low-gamma (30–55 Hz) oscillations to delta (1–4 Hz) oscillations is negatively correlated with the extent to which wild-type (WT) mice explore a novel environment.Clock-Δ19 mice, which display hyperactivity in the novel environment, exhibit profound deficits in low-gamma and NAC single-neuron phase coupling. We also demonstrate that NAC neurons inClock-Δ19 mice display complex changes in dendritic morphology and reduced GluR1 expression compared to those observed in WT littermates. Chronic lithium treatment ameliorated several of these neurophysiological deficits and suppressed exploratory drive in the mutants. These results demonstrate that disruptions ofClockgene function are sufficient to promote alterations in NAC microcircuits, and raise the hypothesis that dysfunctional NAC phase signaling may contribute to the mania-like behavioral manifestations that result from diminished circadian gene function.
Dynamics of Excitability over Extended Timescales in Cultured Cortical Neurons
Authors: Gal Asaf , Eytan Danny , Wallach Avner , Sandler Maya , Schiller Jackie , Marom Shimon
Published: December 2010

Although neuronal excitability is well understood and accurately modeled over timescales of up to hundreds of milliseconds, it is currently unclear whether extrapolating from this limited duration to longer behaviorally relevant timescales is appropriate. Here we used an extracellular recording and stimulation paradigm that extends the duration of single-neuron electrophysiological experiments, exposing the dynamics of excitability in individual cultured cortical neurons over timescales hitherto inaccessible. We show that the long-term neuronal excitability dynamics is unstable and dominated by critical fluctuations, intermittency, scale-invariant rate statistics, and long memory. These intrinsic dynamics bound the firing rate over extended timescales, contrasting observed short-term neuronal response to stimulation onset. Furthermore, the activity of a neuron over extended timescales shows transitions between quasi-stable modes, each characterized by a typical response pattern. Like in the case of rate statistics, the short-term onset response pattern that often serves to functionally define a given neuron is not indicative of its long-term ongoing response. These observations question the validity of describing neuronal excitability based on temporally restricted electrophysiological data, calling for in-depth exploration of activity over wider temporal scales. Such extended experiments will probably entail a different kind of neuronal models, accounting for the unbounded range, from milliseconds up.
The Neonatal Resuscitation Program: The Evidence Evaluation Process and Anticipating Edition 6
Authors: Kattwinkel John , Perlman Jeffrey
Published: December 2010

The Neonatal Resuscitation Program (NRP), published by the American Academy of Pediatrics (AAP) and American Heart Association (AHA), has been in existence for 23 years, and the 6th edition of the NRP Textbook will be published soon. Today, more than 3 million perinatal health professionals have received NRP participation cards, and many hospitals are now requiring evidence of NRP completion before permitting physicians to admit newborns or staff to work in delivery areas. This article describes the evolution of the evidence evaluation process, the questions that have been posed over the past 5 years about the most appropriate neonatal resuscitation techniques, the process that the AAP and AHA have implemented to address those questions, and the major changes that have been incorporated into the upcoming edition of the NRP Textbook.
Congenital Infections, Part 2: Parvovirus,Listeria, Tuberculosis, Syphilis, and Varicella
Authors: Satti Komal Fayyaz , Ali Syed Asad , Weitkamp Jörn-Hendrik
Published: December 2010

The purpose of this two-part series on congenital infections is to provide the reader with an update on recent controversies and advances for a selected group of congenital infections. Part 1 covered cytomegalovirus, toxoplasmosis, rubella, and herpes simplex. This article focuses on parvovirus, Listeria, tuberculosis, syphilis, and varicella, offering a brief overview of rare and unusual causes for congenital infection.
Effects of Traditional Swaddling on Development: A Randomized Controlled Trial
Authors: Manaseki-Holland Semira , Spier Elizabeth , Bavuusuren Bayasgalantai , Bayandorj Tsogzolma , Sprachman Susan , Marshall Tom
Published: December 2010

OBJECTIVE:

Evidence of the effects of tight, prolonged binding of infants on development is inconclusive and based on small ethnographic studies. The null hypothesis was that Mongolian infants not swaddled or swaddled tightly in a traditional setting (to >7 months of age) do not have significantly different scores for the Bayley Scales of Infant Development, Second Edition (BSID-II).

PATIENTS AND METHODS:

In a randomized controlled trial, 1279 healthy newborns in Ulaanbaatar, Mongolia, were allocated at birth to traditional swaddling or nonswaddling. The families received 7 months of home visits to collect data and monitor compliance. At 11 to 17 months of age, the BSID-II was administered to 1100 children.

RESULTS:

No significant between-group differences were found in mean scaled mental and psychomotor developmental scores. The unadjusted mean difference between the groups was −0.69 (95% confidence interval [CI]: −2.59 to 1.19) for psychomotor and −0.42 (95% CI: −1.68 to 0.84) for mental scores in favor of the swaddling group. A subgroup analysis of the compliant sample produced similar results. BSID-II–scaled psychomotor and mental scores were 99.98 (95% CI: 99.03–100.92) and 105.52 (95% CI: 104.89–106.14), respectively. Background characteristics were balanced across the groups.

CONCLUSIONS:

In the Mongolian context, prolonged swaddling in the first year of life did not have any significant impact on children's early mental or psychomotor development. Additional studies in other settings need to confirm this finding. The Mongolian infants in this trial had scaled BSID-II mental and psychomotor scores comparable to United States norms.
Developmental Screening and Parents' Written Comments: An Added Dimension to the Parents' Evaluation of Developmental Status Questionnaire
Authors: Cox Joanne E. , Huntington Noelle , Saada Adrianna , Epee-Bounya Alexandra , Schonwald Alison D.
Published: December 2010

OBJECTIVE:

The aim of this study was to better understand the utility of using the Parents' Evaluation of Developmental Status (PEDS) in well-child visits by analyzing themes and patterns in parents' written responses on the PEDS form.

METHODS:

We reviewed a consecutive sample of medical records with PEDS forms for children aged 6 months to 9 years (site 1) and 3 to 5 years (site 2). We recorded the concerns that parents identified in response to the 10 PEDS questions along with demographic information. We then categorized parents' written comments about those concerns according to comment content. We used qualitative and quantitative methods for analysis.

RESULTS:

We collected 752 PEDS forms. Ninety percent of the parents endorsed at least 1 concern (94.6% on the English forms versus 69.7% on the Spanish forms; P < .001). Parents qualified 27.5% of their concerns with a written comment. In 23.9% of cases in which parents identified a concern and provided a written comment, the content of the comment did not match the question's intent; rates of mismatch were similar for the English and Spanish forms. Among comments regarding behavioral concerns, 12% reflected a misunderstanding of age-appropriate behavior. Medical concerns accounted for 14.1% of the comments; these concerns were more common on English forms (61.3%) than on Spanish forms (1.7%) (P < .08). More than one-fourth of the comments reported behavior or development that was on target or advanced for the child's age.

CONCLUSIONS:

Parents frequently used the PEDS forms to communicate additional concerns regarding their child or provide positive feedback on their child's progress. The inappropriate developmental expectations, limited health literacy, and culturally distinct comments on the PEDS forms reinforce the importance of using screening tools to enhance the care provided during visits but not to replace patient-provider communication.
Growth in Children with Clefts: Serial Hand-Wrist X-Ray Evidence
Authors: Bowers Evelyn J.
Published: December 2010

Objective

Serial hand-wrist x-rays were assessed for Tanner-Whitehouse 2 skeletal ages of children with cleft palate, unilateral cleft lip and palate, and bilateral cleft lip and palate. The skeletal ages were compared by cleft type to see whether growth delay might explain the small body size for age and delayed maturation sometimes seen elsewhere in children with clefts.

Design

This is a retrospective study of serial x-rays collected between 1950 and 1968 at the Philadelphia Growth Center. The author was blind to age, sex, and diagnosis while reading these films.

Participants

These x-rays were taken as part of routine auxological evaluation of the normality of growth status.

Main Outcome Measures

Distributions of skeletal age patterns in advance of or delayed from chronological age and frequencies of clinically significant deviant patterns are presented.

Conclusions

Boys and girls with cleft palate show different maturational patterns, supporting a sex influence on the etiologies of at least some of these anomalies. Boys with unilateral cleft lip and palate and bilateral cleft lip and palate have different maturational patterns, consistent with these anomalies having different sets of etiological factors. Girls with unilateral cleft lip and palate almost always have advanced skeletal ages; whereas, boys sometimes do not. These results support the need for keeping both sex and diagnostic categories separate when conducting etiological searches.
Interactions of environmental stressors impact survival and development of parasitized larval amphibians
Authors: Koprivnikar J.
Published: December 2010

Infected hosts are exposed to many environmental stressors that must be taken into account in order to determine the importance of disease, as various combinations can interact in unpredictable ways. Here, northern leopard frog (Rana pipiens) tadpoles, a species in decline, were exposed to stressors singly or in combination. Stressors included infection byEchinostoma trivolvis(a trematode parasite), exposure to predator chemical cues (larval dragonflies), and exposure to varying concentrations of the herbicide atrazine. Parasitism decreased survival only in combination with exposure to 3 μg/L atrazine, with a negative interaction observed for mass as well. Similarly, a negative interaction of parasitism and predation on survival occurred. However, atrazine exposure alone negatively affected the survival, mass, and developmental stage of tadpoles. These results indicate that certain stressor combinations are particularly deleterious for young parasitized tadpoles. Notably, very common low‐intensity parasite infection can be particularly harmful in certain situations. Such negative impacts on larval amphibians in certain scenarios may contribute to ongoing amphibian population declines, emphasizing that the combination of environmental stressors must be considered when evaluating the general role of disease in species extinctions.