bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe Early Life Stress Hampers Spatial Learning and Neurogenesis, but Improves Hippocampal Synaptic Plasticity and Emotional Learning under High-Stress Conditions in Adulthood
Authors: Oomen Charlotte A. , Soeters Heleen , Audureau Nathalie , Vermunt Lisa , van Hasselt Felisa N. , Manders Erik M. M. , Joëls Marian , Lucassen Paul J. , Krugers Harm
Published: May 2010

Early life stress increases the risk for developing stress-related pathologies later in life. Recent studies in rats suggest that mild early life stress, rather than being overall unfavorable, may program the hippocampus such that it is optimally adapted to a stressful context later in life. Here, we tested whether this principle of “adaptive programming” also holds under severely adverse early life conditions, i.e., 24 h of maternal deprivation (MD), a model for maternal neglect. In young adult male rats subjected to MD on postnatal day 3, we observed reduced levels of adult hippocampal neurogenesis as measured by cell proliferation, cell survival, and neuronal differentiation. Also, mature dentate granule cells showed a change in their dendritic morphology that was most noticeable in the proximal part of the dendritic tree. Lasting structural changes due to MD were paralleled by impaired water maze acquisition but did not affect long-term potentiation in the dentate gyrus. Importantly, in the presence of high levels of the stress hormone corticosterone, even long-term potentiation in the dentate gyrus of MD animals was facilitated. In addition to this, contextual learning in a high-stress environment was enhanced in MD rats. These morphological, electrophysiological, and behavioral observations show that even a severely adverse early life environment does not evolve into overall impaired hippocampal functionality later in life. Rather, adversity early in life can prepare the organism to perform optimally under conditions associated with high corticosteroid levels in adulthood.
Cell Type-Specific Expression of Acid-Sensing Ion Channels in Hippocampal Interneurons
Authors: Weng Ju-Yun , Lin Yen-Chu , Lien Cheng-Chang
Published: May 2010

Acid-sensing ion channels (ASICs), a member of the degenerin/epithelial Na+channel superfamily, are widely expressed in the mammalian CNS. Accumulating evidence suggests that ASIC current density is higher in GABAergic interneurons than that in glutamatergic pyramidal neurons (PNs) in the hippocampus. Such differential expression of ASICs in cortical networks is thought to be a key element for seizure termination. However, GABAergic interneurons are highly diverse; it is unclear whether the functional expression of ASICs differs in distinct GABAergic interneuron subtypes. Moreover, the subunit composition of ASICs in individual GABAergic interneurons remains unknown. By combining patch-clamp recording and single-cell reverse transcription (RT)-PCR analysis, we correlated ASIC currents with their gene expression in acute rat hippocampal slices. The results yielded several surprising findings. First, ASIC current density of oriens lacunosum-moleculare (O-LM) cells in the CA1 region, a classical type of dendrite-targeting interneuron, is 6 times greater than that of fast-spiking basket cells (BCs) in the dentate gyrus, a major class of soma-targeting interneuron. Second, the recovery of ASICs from desensitization is slowest in BCs, intermediate in PNs, and fastest in O-LM cells. Third, the tarantula venom psalmotoxin 1, the specific blocker for ASIC1a homomers, inhibits ASIC currents in BCs but not in O-LM cells. Finally, single-cell RT-PCR analysis reveals coexpression of ASIC1a and ASIC2 subunit transcripts in O-LM cells, whereas only ASIC1a subunit transcript is detected in most BCs. Thus, differential expression of ASICs in inhibitory microcircuits likely contributes to the distinct roles of GABAergic interneurons in normal physiology and pathophysiology.
Downregulation of Dendritic HCN Channel Gating in Epilepsy Is Mediated by Altered Phosphorylation Signaling
Authors: Jung Sangwook , Bullis James B. , Lau Ignatius H. , Jones Terrance D. , Warner Lindsay N. , Poolos Nicholas P.
Published: May 2010

The onset of spontaneous seizures in the pilocarpine model of epilepsy causes a hyperpolarized shift in the voltage-dependent activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channel-mediated current (Ih) in CA1 hippocampal pyramidal neuron dendrites, contributing to neuronal hyperexcitability and possibly to epileptogenesis. However, the specific mechanisms by which spontaneous seizures cause downregulation of HCN channel gating are yet unknown. We asked whether the seizure-dependent downregulation of HCN channel gating was due to altered phosphorylation signaling mediated by the phosphatase calcineurin (CaN) or the kinase p38 mitogen-activated protein kinase (p38 MAPK). We first found that CaN inhibition upregulated HCN channel gating and reduced neuronal excitability under normal conditions, showing that CaN is a strong modulator of HCN channels. We then found that anin vitromodel of seizures (1 h in 0 Mg2+and 50 μmbicuculline at 35–37°C) reproduced the HCN channel gating change seenin vivo. Pharmacological inhibition of CaN or activation of p38 MAPK partially reversed thein vitroseizure-induced hyperpolarized shift in HCN channel gating, and the shift was fully reversed by the combination of CaN inhibition and p38 MAPK activation. We then demonstrated enhanced CaN activity as well as reduced p38 MAPK activityin vivoin the CA1 hippocampal area of chronically epileptic animals. Pharmacological reversal of these phosphorylation changes restored HCN channel gating downregulation and neuronal hyperexcitability in epileptic tissue to control levels. Together, these results suggest that alteration of two different phosphorylation pathways in epilepsy contributes to the downregulation of HCN channel gating, which consequently produces neuronal hyperexcitability and thus may be a target for novel antiepileptic therapies.
Acute γ-Secretase Inhibition of Nonhuman Primate CNS Shifts Amyloid Precursor Protein (APP) Metabolism from Amyloid-β Production to Alternative APP Fragments without Amyloid-β Rebound
Authors: Cook Jacquelynn J. , Wildsmith Kristin R. , Gilberto David B. , Holahan Marie A. , Kinney Gene G. , Mathers Parker D. , Michener Maria S. , Price Eric A. , Shearman Mark S. , Simon Adam J. , Wang Jennifer X. , Wu Guoxin , Yarasheski Kevin E. , Bateman Randall J.
Published: May 2010

The accumulation of amyloid β (Aβ) in Alzheimer's disease is caused by an imbalance of production and clearance, which leads to increased soluble Aβ species and extracellular plaque formation in the brain. Multiple Aβ-lowering therapies are currently in development: an important goal is to characterize the molecular mechanisms of action and effects on physiological processing of Aβ, as well as other amyloid precursor protein (APP) metabolites, in models which approximate human Aβ physiology. To this end, we report the translation of the humanin vivostable-isotope-labeling kinetics (SILK) method to a rhesus monkey cisterna magna ported (CMP) nonhuman primate model, and use the model to test the mechanisms of action of a γ-secretase inhibitor (GSI). A major concern of inhibiting the enzymes which produce Aβ (β- and γ-secretase) is that precursors of Aβ may accumulate and cause a rapid increase in Aβ production when enzyme inhibition discontinues. In this study, the GSI MK-0752 was administered to conscious CMP rhesus monkeys in conjunction within vivostable-isotope-labeling, and dose-dependently reduced newly generated CNS Aβ. In contrast to systemic Aβ metabolism, CNS Aβ production was not increased after the GSI was cleared. These results indicate that most of the CNS APP was metabolized to products other than Aβ, including C-terminal truncated forms of Aβ: 1-14, 1-15 and 1-16; this demonstrates an alternative degradation pathway for CNS amyloid precursor protein during γ-secretase inhibition.
Guidance of Postural Motoneurons Requires MAPK/ERK Signaling Downstream of Fibroblast Growth Factor Receptor 1
Authors: Soundararajan Prabakaran , Fawcett James P. , Rafuse Victor F.
Published: May 2010

Identification of intracellular signaling pathways necessary for appropriate axon guidance is challenging because many CNS populations used to study these events contain multiple cell types. Here, we resolve this issue by using mouse embryonic stem (ES) cells that were directed to differentiate into a population of motoneurons that exclusively innervate epaxial muscles [medial median motor column (MMCm) motoneurons]. These ES cell-derived MMCm motoneurons, like their endogenous counterparts, express fibroblast growth factor receptor 1 (FGFR1) and selectively extend axons toward the epaxial trophin FGF8. Unlike wild-type MMCm motoneurons,FGFR1−/−MMCm motoneurons show guidance defects when transplanted into the neural tube of chick embryos. Furthermore, activation of FGFR1 selectively signals through mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) for appropriate guidancein vitro, whereas overexpression of constitutively active MAPK/ERK in transplanted, or endogenous chick, MMCm cells causes guidance defectsin vivo. These results indicate that MAPK/ERK activation downstream of FGFR1 is necessary for MMCm motor axon guidance and that ES cell-derived neurons provide an important tool for dissecting intracellular pathways required for axon guidance.
Functional Characterization of α9-Containing Cholinergic Nicotinic Receptors in the Rat Adrenal Medulla: Implication in Stress-Induced Functional Plasticity
Authors: Colomer Claude , Olivos-Oré Luis A. , Vincent Anne , McIntosh J. Michael , Artalejo Antonio R. , Guérineau Nathalie C.
Published: May 2010

An increase in circulating adrenal catecholamine levels constitutes one of the mechanisms whereby organisms cope with stress. Accordingly, stimulus-secretion coupling within the stressed adrenal medullary tissue undergoes persistent remodeling. In particular, cholinergic synaptic neurotransmission between splanchnic nerve terminals and chromaffin cells is upregulated in stressed rats. Since synaptic transmission is mainly supported by activation of postsynaptic neuronal acetylcholine nicotinic receptors (nAChRs), we focused our study on the role of α9-containing nAChRs, which have been recently described in chromaffin cells. Taking advantage of their specific blockade by the α-conotoxin RgIA (α-RgIA), we unveil novel functional roles for these receptors in the stimulus-secretion coupling of the medulla. First, we show that in rat acute adrenal slices, α9-containing nAChRs codistribute with synaptophysin and significantly contribute to EPSCs. Second, we show that these receptors are involved in the tonic inhibitory control exerted by cholinergic activity on gap junctional coupling between chromaffin cells, as evidenced by an increased Lucifer yellow diffusion within the medulla in α-RgIA-treated slices. Third, we unexpectedly found that α9-containing nAChRs dominantly (>70%) contribute to acetylcholine-induced current in cold-stressed rats, whereas α3 nAChRs are the main contributing channels in unstressed animals. Consistently, expression levels of α9 nAChR transcript and protein are overexpressed in cold-stressed rats. As a functional relevance, we propose that upregulation of α9-containing nAChR channels and ensuing dominant contribution in cholinergic signaling may be one of the mechanisms whereby adrenal medullary tissue appropriately adapts to increased splanchnic nerve electrical discharges occurring in stressful situations.
LGI1 Is a Nogo Receptor 1 Ligand that Antagonizes Myelin-Based Growth Inhibition
Authors: Thomas Rhalena , Favell Kristy , Morante-Redolat Jose , Pool Madeline , Kent Christopher , Wright Melissa , Daignault Kathleen , Ferraro Gino B. , Montcalm Samuel , Durocher Yves , Fournier Alyson , Perez-Tur Jordi , Barker Philip A.
Published: May 2010

Mutations in leucine-rich glioma inactivated (LGI1) are a genetic cause of autosomal dominant temporal lobe epilepsy with auditory features. LGI1 is a secreted protein that shares homology with members of the SLIT family, ligands that direct axonal repulsion and growth cone collapse, and we therefore considered the possibility that LGI1 may regulate neuronal process extension or growth cone collapse. Here we report that LGI1 does not affect growth directly but instead enhances neuronal growth on myelin-based inhibitory substrates and antagonizes myelin-induced growth cone collapse. We show that LGI1 mediates this effect by functioning as a specific Nogo receptor 1 (NgR1) ligand that antagonizes the action of myelin-based inhibitory cues. Finally, we demonstrate that NgR1 and ADAM22 physically associate to form a receptor complex in which NgR1 facilitates LGI1 binding to ADAM22.
Analysis of the Context Integration Mechanisms Underlying Figure–Ground Organization in the Visual Cortex
Authors: Zhang Nan R. , von der Heydt Rüdiger
Published: May 2010

Most neurons in visual cortex respond to contrast borders and are orientation selective, and some are also selective for which side of a border is figure and which side is ground (“border ownership coding”). These neurons are influenced by the image context far beyond the classical receptive field (CRF) and as early as 25 ms after the onset of activity in the cortex. The nature of the fast context integration mechanism is not well understood. What parts of a figure contribute to the context effect? What is the structure of the “extraclassical surround”? Is the context information propagated through horizontal fibers within cortex or through reciprocal connections via higher-level areas? To address these questions, we studied border ownership modulation with fragmented figures. Neurons were recorded in areas V1 and V2 ofMacaca mulattaunder behaviorally induced fixation. Test figures were fragmented rectangles. While one edge was centered on the CRF, the presence of the fragments outside the CRF was varied. The surround fragments produced facilitation on the preferred border ownership side as well as suppression on the nonpreferred side, with ∼80% of the locations contributing on average. Fragments far from the CRF influenced the responses even in the absence of fragments closer to the CRF, and without the extra delay that would incur from propagation through horizontal fibers. Three principally different models are discussed. The results support a model in which the antagonistic surround influences are produced by reentrant signals from a higher-level area.
Demyelination Increases Axonal Stationary Mitochondrial Size and the Speed of Axonal Mitochondrial Transport
Authors: Kiryu-Seo Sumiko , Ohno Nobuhiko , Kidd Grahame J. , Komuro Hitoshi , Trapp Bruce D.
Published: May 2010

Axonal degeneration contributes to permanent neurological disability in inherited and acquired diseases of myelin. Mitochondrial dysfunction has been proposed as a major contributor to this axonal degeneration. It remains to be determined, however, if myelination, demyelination, or remyelination alter the size and distribution of axonal mitochondrial stationary sites or the rates of axonal mitochondrial transport. Using live myelinated rat dorsal root ganglion (DRG) cultures, we investigated whether myelination and lysolecithin-induced demyelination affect axonal mitochondria. Myelination increased the size of axonal stationary mitochondrial sites by 2.3-fold. After demyelination, the size of axonal stationary mitochondrial sites was increased by an additional 2.2-fold and the transport velocity of motile mitochondria was increased by 47%. These measures returned to the levels of myelinated axons after remyelination. Demyelination induced activating transcription factor 3 (ATF3) in DRG neurons. Knockdown of neuronal ATF3 by short hairpin RNA abolished the demyelination-induced increase in axonal mitochondrial transport and increased nitrotyrosine immunoreactivity in axonal mitochondria, suggesting that neuronal ATF3 expression and increased mitochondrial transport protect demyelinated axons from oxidative damage. In response to insufficient ATP production, demyelinated axons increase the size of stationary mitochondrial sites and thereby balance ATP production with the increased energy needs of nerve conduction.
Altered GABAAReceptor-Mediated Synaptic Transmission Disrupts the Firing of Gonadotropin-Releasing Hormone Neurons in Male Mice under Conditions That Mimic Steroid Abuse
Authors: Penatti Carlos A. A. , Davis Matthew C. , Porter Donna M. , Henderson Leslie P.
Published: May 2010

Gonadotropin-releasing hormone (GnRH) neurons are the central regulators of reproduction. GABAergic transmission plays a critical role in pubertal activation of pulsatile GnRH secretion. Self-administration of excessive doses of anabolic androgenic steroids (AAS) disrupts reproductive function and may have critical repercussions for pubertal onset in adolescent users. Here, we demonstrate that chronic treatment of adolescent male mice with the AAS 17α-methyltestosterone significantly decreased action potential frequency in GnRH neurons, reduced the serum gonadotropin levels, and decreased testes mass. AAS treatment did not induce significant changes in GABAAreceptor subunit mRNA levels or alter the amplitude or decay kinetics of GABAAreceptor-mediated spontaneous postsynaptic currents (sPSCs) or tonic currents in GnRH neurons. However, AAS treatment significantly increased action potential frequency in neighboring medial preoptic area (mPOA) neurons and GABAAreceptor-mediated sPSC frequency in GnRH neurons. In addition, physical isolation of the more lateral aspects of the mPOA from the medially localized GnRH neurons abrogated the AAS-induced increase in GABAAreceptor-mediated sPSC frequency and the decrease in action potential firing in the GnRH cells. Our results indicate that AAS act predominantly on steroid-sensitive presynaptic neurons within the mPOA to impart significant increases in GABAAreceptor-mediated inhibitory tone onto downstream GnRH neurons, resulting in diminished activity of these pivotal mediators of reproductive function. These AAS-induced changes in central GABAergic circuits of the forebrain may significantly contribute to the disruptive actions of these drugs on pubertal maturation and the development of reproductive competence in male steroid abusers.
Low Concentrations of Alcohol Inhibit BDNF-Dependent GABAergic Plasticity via L-type Ca2+Channel Inhibition in Developing CA3 Hippocampal Pyramidal Neurons
Authors: Zucca Stefano , Valenzuela C. Fernando
Published: May 2010

Fetal alcohol spectrum disorder (FASD) is associated with learning and memory alterations that could be, in part, a consequence of hippocampal damage. The CA3 hippocampal subfield is one of the regions affected by ethanol (EtOH), including exposure during the third trimester-equivalent (i.e., neonatal period in rats). However, the mechanism of action of EtOH is poorly understood. In CA3 pyramidal neurons from neonatal rats, dendritic BDNF release causes long-term potentiation of the frequency of GABAAreceptor-mediated spontaneous postsynaptic currents (LTP-GABAA) and this mechanism is thought to play a role in GABAergic synapse maturation. Here, we show that short- and long-term exposure of neonatal male rats to low EtOH concentrations abolishes LTP-GABAAby inhibiting L-type voltage-gated Ca2+channels. These findings support the recommendation that even light drinking should be avoided during pregnancy.
Tissue Plasminogen Activator Alters Intracellular Sequestration of Zinc through Interaction with the Transporter ZIP4
Authors: Emmetsberger Jaime , Mirrione Martine M. , Zhou Chun , Fernandez-Monreal Monica , Siddiq Mustafa M. , Ji Kyungmin , Tsirka Stella E.
Published: May 2010

Glutamatergic neurons contain free zinc packaged into neurotransmitter-loaded synaptic vesicles. Upon neuronal activation, the vesicular contents are released into the synaptic space, whereby the zinc modulates activity of postsynaptic neurons though interactions with receptors, transporters and exchangers. However, high extracellular concentrations of zinc trigger seizures and are neurotoxic if substantial amounts of zinc reenter the cells via ion channels and accumulate in the cytoplasm. Tissue plasminogen activator (tPA), a secreted serine protease, is also proepileptic and excitotoxic. However, tPA counters zinc toxicity by promoting zinc import back into the neurons in a sequestered form that is nontoxic. Here, we identify the zinc influx transporter, ZIP4, as the pathway through which tPA mediates the zinc uptake. We show that ZIP4 is upregulated after excitotoxin stimulation of the mouse, male and female, hippocampus. ZIP4 physically interacts with tPA, correlating with an increased intracellular zinc influx and lysosomal sequestration. Changes in prosurvival signals support the idea that this sequestration results in neuroprotection. These experiments identify a mechanism via which neurons use tPA to efficiently neutralize the toxic effects of excessive concentrations of free zinc.
Short- and Long-Term Memory Are Modulated by Multiple Isoforms of the Fragile X Mental Retardation Protein
Authors: Banerjee Paromita , Schoenfeld Brian P. , Bell Aaron J. , Choi Catherine H. , Bradley Michael P. , Hinchey Paul , Kollaros Maria , Park Jae H. , McBride Sean M. J. , Dockendorff Thomas C.
Published: May 2010

The diversity of protein isoforms arising from alternative splicing is thought to modulate fine-tuning of synaptic plasticity. Fragile X mental retardation protein (FMRP), a neuronal RNA binding protein, exists in isoforms as a result of alternative splicing, but the contribution of these isoforms to neural plasticity are not well understood. We show that two isoforms ofDrosophila melanogasterFMRP (dFMR1) have differential roles in mediating neural development and behavior functions conferred by thedfmr1gene. These isoforms differ in the presence of a protein interaction module that is related to prion domains and is functionally conserved between FMRPs. Expression of both isoforms is necessary for optimal performance in tests of short- and long-term memory of courtship training. The presence or absence of the protein interaction domain may govern the types of ribonucleoprotein (RNP) complexes dFMR1 assembles into, with different RNPs regulating gene expression in a manner necessary for establishing distinct phases of memory formation.
A Lesson on Evolution & Natural Selection
Authors: Curtis Anthony D.
Published: May 2010

I describe three activities that allow students to explore the ideas of evolution, natural selection, extinction, mass extinction, and rates of evolutionary change by engaging a simple model using paper, pens, chalk, and a chalkboard. As a culminating activity that supports expository writing in the sciences, the students write an essay on mass extinction. All activities are geared for high school biology and perhaps introductory college biology classes. With little modification, activities 1 and 2 can be used successfully in middle school and perhaps in the higher elementary grade levels.
Darwin's “Imaginary Illustrations”: Creatively Teaching Evolutionary Concepts & the Nature of Science
Authors: Love Alan C.
Published: May 2010

An overlooked feature of Darwin's work is his use of “imaginary illustrations” to show that natural selection is competent to produce adaptive, evolutionary change. When set in the context of Darwin's methodology, these thought experiments provide a novel way to teach natural selection and the nature of science.
Florida Teachers' Attitudes about Teaching Evolution
Authors: Fowler Samantha R. , Meisels Gerry G.
Published: May 2010

A survey of Florida teachers reveals many differences in comfort level with teaching evolution according to the state's science teaching standards, general attitudes and beliefs about evolution, and the extent to which teachers are criticized, censured, disparaged, or reprehended for their beliefs about the teaching of evolution.
Using a Five-Step Procedure for Inferential Statistical Analyses
Authors: Kamin Lawrence F.
Published: May 2010

Many statistics texts pose inferential statistical problems in a disjointed way. By using a simple five-step procedure as a template for statistical inference problems, the student can solve problems in an organized fashion. The problem and its solution will thus be a stand-by-itself organic whole and a single unit of thought and effort. The described procedure can be used for both parametric and nonparametric inferential tests. The example given is a chi-square goodness-of-fit test of a genetics experiment involving a dihybrid cross in corn that follows a 9:3:3:1 ratio. This experimental analysis is commonly done in introductory biology labs.
Creating Clay Models of a Human Torso as an Alternative to Dissection
Authors: Shipley Gwendolyn
Published: May 2010

Instead of dissecting animals, students create small clay models of human internal organs to demonstrate their understanding of the positioning and interlocking shapes of the organs. Not only is this approach more environmentally friendly, it also forces them to learn human anatomy – which is more relevant to them than the anatomy of other creatures – in a creative and constructive manner. The article includes photos of students' work, a table for evaluation (grading rubric), and a list of materials, as well as some helpful hints.
Biology Blogs: An Online Journal Club & Assessment Tool
Authors: De Souza-Hart Janet A.
Published: May 2010

A “blog” can be used as an online journal club to supplement classroom learning. When crafted in a certain way, it can help students develop their scientific reading comprehension, critical thinking, and writing skills in a way that can easily be assessed by educators.
Using the NCBI Genome Databases to Compare the Genes for Human & Chimpanzee Beta Hemoglobin
Authors: Offner Susan
Published: May 2010

The beta hemoglobin protein is identical in humans and chimpanzees. In this tutorial, students see that even though the proteins are identical, the genes that code for them are not. There are many more differences in the introns than in the exons, which indicates that coding regions of DNA are more highly conserved than non-coding regions.
Epigenetic Effects of Diet on Fruit Fly Lifespan: An Investigation to Teach Epigenetics to Biology Students
Authors: Billingsley James , Carlson Kimberly A.
Published: May 2010

Do our genes exclusively control us, or are other factors at play? Epigenetics can provide a means for students to use inquiry-based methods to understand a complex biological concept. Students research and design an experiment testing whether dietary supplements affect the lifespan of Drosophila melanogaster over multiple generations.
The Y Chromosome
Authors: Offner Susan
Published: May 2010

The Y chromosome is of great interest to students and can be used to teach about many important biological concepts in addition to sex determination. This paper discusses mutation, recombination, mammalian sex determination, sex determination in general, and the evolution of sex determination in mammals. It includes a student activity that illustrates how sex is determined in people.
Using the Mystery of the Cyclopic Lamb to Teach Biotechnology
Authors: Jensen Jamie L.
Published: May 2010

I present a learning cycle that explores different biotechnologies using the process of in situ hybridization as a platform. Students are presented with a cyclopic lamb and must use biotechnology to discover the mechanism behind the deformity. Through this activity, students learn about signal transduction and discover the processes of polymerase chain reaction, gel electrophoresis, restriction enzyme digests and ligations, cloning, and transformation. Students also discover the nature of scientific inquiry and practice hypothetico-deductive reasoning.
Bling My Research! A Mock Grant Panel Activity Illustrating the Importance of Basic Research
Authors: Leander Celeste A. , Whitton Jeannette
Published: May 2010

First-year university students have misconceptions about the source and dynamics of publicly funded research money. We designed an activity in which students take part in a mock grant panel. The results indicated a strong tendency toward student funding of applied medical research at the expense of basic research. Exposure to a few examples of important basic research moderates this tendency.
A Simple Computer Application for the Identification of Conifer Genera
Authors: Strain Steven R. , Chmielewski Jerry G.
Published: May 2010

The National Science Education Standards prescribe that an understanding of the importance of classifying organisms be one component of a student's educational experience in the life sciences. The use of a classification scheme to identify organisms is one way of addressing this goal. We describe Conifer ID, a computer application that assists students in the identification of conifers without requiring prior specific knowledge. Conifer ID promotes careful observational skills and presents students with visual aids during the identification to overcome some of the weaknesses of more traditional identification methods.
Serial Dilution Simulation Lab
Authors: Keler Cynthia , Balutis Tabitha , Bergen Kim , Laudenslager Bryanna , Rubino Deanna
Published: May 2010

Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.
Solid-State Chemistry in France: Structures and Dynamics of a Scientific Community Since World War II
Authors: Teissier Pierre
Published: May 2010

This paper tells the history of solid-state chemistry in France from 1945 to the present. There, the chemical study of solids was carried out by a national, academic community of solid-state chemists, which went through three successive organizational regimes. It was first framed by prewar traditions, taking the form of a feudal regime of Parisian research schools until the late 1950s. As the first post-World War II generation gained power and influence, research schools tended to drop their local specificity and the same disciplinary matrix spread across the country. This disciplinary regime was made possible through the centralized administration of the Centre national de la recherche scientifique (CNRS). Finally, a multiplication of practices and socializations blurred common standards in the 1980s, which shifted the community toward a cluster regime where numerous thematic groups loosely interacted under a broader umbrella influenced by materials science.

This case study investigates the institutional and epistemic structures and dynamics of a scientific community in a national context. The empirical analysis relies heavily on oral history, which affords special attention to the perceptions, discourses, and identities of the actors. The self-identification of chemists not only reflected their own beliefs but also constantly referred to their alter egos, the French solidstate physicists.
Aberrant expression of multiple hormone receptors in ACTH-independent macronodular adrenal hyperplasia causing Cushing's syndrome
Authors: de Groot J W B , Links T P , Themmen A P N , Looijenga L H , de Krijger R R , van Koetsveld P M , Hofland J , van den Berg G , Hofland L J , Feelders R A
Published: May 2010

Objective

Aberrant adrenal expression of various hormone receptors has been identified in ACTH-independent macronodular adrenal hyperplasia (AIMAH) causing cortisol hypersecretion regulated by hormones other than ACTH. We aimed to determine aberrant expression of multiple hormone receptors in vivo and in vitro in adrenal tissue of a patient with AIMAH.

Design

The design of the study includes clinical case description, and biochemical and immunohistochemical analysis to demonstrate aberrant expression of multiple hormone receptors in AIMAH.

Methods

The subject of the study is a male diagnosed with Cushing's syndrome because of AIMAH. Directly after laparoscopic removal of the adrenals, adrenal tissue was incubated with and without test substances (ACTH, forskolin, arginine vasopressin (AVP), desmopressin, epinephrine, norepinephrine, purified human chorionic gonadotropin (hCG), metoclopramide and the combinations of AVP with ACTH, epinephrine and metoclopramide). LH/hCG-receptor (hCG-R) immunohistochemistry and RT-PCR analyses were performed to demonstrate aberrant expression of LH/hCG-R and V1–3-AVPR.

Results

AIMAH was characterized by in vivo cortisol responsiveness to AVP and in vitro cortisol responses to AVP, hCG, epinephrine, and norepinephrine suggesting aberrant adrenal expression of the receptors for AVP (the V1–3-AVPRs), catecholamines (the β-AR), and LH (the LH/hCG-R). Incubation with combinations of AVP and ACTH and of AVP with epinephrine induced a stronger cortisol response compared with incubation with the individual agents. Moreover, we demonstrated adrenal V1–3-AVPR and LH/hCG-R expression.

Conclusions

AIMAH tissue may simultaneously express multiple aberrant hormone receptors, and individual ligands may potentiate each other regarding cell proliferation and cortisol production.
Verification of the technical parameters of head-only electrical stunning of pigs under commercial conditions
Authors: Végh Ákos , Abonyi-Tóth Zsolt , Rafai Pál
Published: May 2010

The European Food Safety Authority recommends a minimum current of 1.3 Amps for the electrical head-only stunning of pigs. However, it is stated as well that ‘the technical reference data for head-only electrical stunning of pigs such as 1.3 Amps are either rather old or worked out under experimental laboratory conditions’. This study was carried out to verify the electrical parameters of pig stunning under commercial conditions. Altogether 145 fattener pigs (body weight range: 30–150 kg, median 109 kg) were tested at four different private slaughterhouses in Hungary where head-only electrical stunners were used with different constant voltage settings. In each case the following data were recorded: individual liveweight (kg), current (A) and voltage (V) (measured with an individually developed analogue device placed in the circuit), current duration (s), effectiveness of stunning, grading of carcass. Correlations between these parameters and effectiveness were examined. Besides that, any correlation between the test parameters and impedance of head was examined. In 128 out of the 145 cases the stunning was effective (88.3%). Effectiveness was significantly related to current but not to other parameters such as voltage and duration of load. Impedance of head was not correlated with the size of the animal and the meat grading scores. Generally, it was concluded that the use of a single electrical parameter (e.g. a minimum current of 1.3 A) as a prerequisite of good stunning is not ideal.
Morphological and apoptotic changes in the intestinal mucosa and lung parenchyma after ischaemic/reperfusion injury of the jejunum
Authors: Varga Ján , Staško Pavel , Tóth Štefan , Pristášová Zuzana , Jonecová Zuzana , Veselá Jarmila , Pomfy Mikuláš
Published: May 2010

Ischaemic/reperfusion (IR) injury of the small intestine may lead to the development of multiple organ failure. Little is known about the morphological changes occurring in the organs during the subacute course of this syndrome. The objective of this study was to observe histopathological features and the role of apoptosis in the jejunal mucosa and lung parenchyma after intestinal IR injury in a long-term experiment. Wistar rats (n = 36) were divided into 4 experimental groups (IR
10
, IR
20
, IR
30
, S). Groups IR
10
, IR
20
and IR
30
(each n = 10) were subjected to 1-hour ischaemia of the cranial mesenteric artery followed by 10, 20 or 30 days of reperfusion, respectively. The control group S (n = 6) was not subjected to ischaemia. The jejunal mucosa remained intact after all periods of reperfusion. Apoptotic cells were found particularly in the lamina propria, with the most significant difference observed in the IR
30
group (P < 0.01). The lung parenchyma had lower regenerative capacity, which was confirmed by a high index of histological damage after 30 days of reperfusion (P < 0.01) and by the presence of an increased number of apoptotic cells, especially in the pulmonary interstitium. The number of apoptotic cells was ten times higher than in the control group (P < 0.001).
Detection of porcine circovirus in rodents — Short communication
Authors: Lőrincz Márta , Cságola Attila , Biksi Imre , Szeredi Levente , Dán Ádám , Tuboly Tamás
Published: May 2010

Porcine circoviruses (PCV) are present worldwide, infecting domestic pigs and wild boars alike. Studies under laboratory conditions indicated that PCV can be taken up by mice and the virus can replicate in these animals. The possible role of rodents in maintaining and transmitting PCV2 infection in the field has not been investigated yet. The present study reports the detection of PCV2, the pathogenic form of the virus, in mice and rats. A number of rodents, such as mice, rats and voles, were collected at PCV2-infected farms and also outside pig herds and tested for the presence of the virus by polymerase chain reaction (PCR). The results indicated that PCV2 can be present both in mice and rats (65.0% and 23.8% positivity, respectively) on the infected premises, but those rodents that were collected outside pig farms remained negative for PCV2.
Renal regulation of sodium, potassium and chloride balance in single- and twin-pregnant goats
Authors: Michałek Katarzyna , Jankowiak Dorota , Ożgo Małgorzata , Skrzypczak Wiesław
Published: May 2010

The aim of these studies was to analyse and compare changes in selected parameters of renal function in terms of water-electrolyte balance regulation in single- and twin-pregnant goats. Clearance analyses were carried out on 16 pregnant White Improved goats (8 in single and 8 in twin gestation). Blood plasma and urine samples were analysed for the concentration of inulin, endogenous creatinine, sodium, potassium, and chlorides. It has been demonstrated that glomerular filtration rate (GFR) in the goat kidney does not change significantly during gestation. GFR recorded from the 1st week until the 20th week of gestation in twin-pregnant goats was only slightly higher compared to those observed in single-pregnant does. Blood plasma concentrations of major electrolytes, i.e. sodium, potassium and chloride ions, did not differ significantly in pregnant and non-pregnant goats, and remained within the reference values. From the very beginning of gestation, the single-pregnant goats showed increased renal potassium clearance; however, the level of sodium clearance remained stable. On the other hand, sodium clearance increased from the 2nd month of gestation in the twin-pregnant goats, while the load of excreted potassium did not change. These changes had probably resulted from varied levels of aldosterone and progesterone and their mutual proportions differing between the groups.
Effect of Agaricus brasiliensis and Lentinula edodes mushrooms on the infection of passionflower with Cowpea aphid-borne mosaic virus
Authors: Di Piero Robson Marcelo , Novaes Quelmo Silva de , Pascholati Sérgio Florentino
Published: May 2010

The objective of the present study was to evaluate the protection of passion fruit plants against CABMV by using preparations from Agaricus brasiliensis and Lentinula edodes mushrooms. In experiments carried out in the greenhouse, the fruiting body extracts from some of the isolates of both mushrooms significantly reduced CABMV incidence in passion fruit plants. This protective effect occurred when the plant leaves, pre-treated with extracts, were later inoculated mechanically with the virus. However, the extracts did not protect the plants in experiments involving CABMV transmission by aphid vectors. An inhibitory effect of mushroom extracts on the virus particles was also demonstrated on Chenopodium quinoa, a CABMV local lesion host, by inoculating the plants with a mixture of extracts and virus suspension. Still in C. quinoa, the mushroom extracts from some isolates induced systemic resistance against the virus. These results showed that aqueous extracts from A. brasiliensis and L. edodes fruiting bodies had CABMV infectivity inhibitors, but that was not enough to control the viral disease on passion fruit plants at all, considering they were infected through a vector.
Kinetic analysis of in vitro production of wild-type Spodoptera frugiperda nucleopolyhedrovirus
Authors: Almeida Andréa Farias de , Macedo Gorete Ribeiro de , Chan Leslie Chee Loong , Pedrini Márcia Regina da Silva
Published: May 2010

In this study, the kinetic behavior of Sf9 and Sf21 cells used in the production of a baculovirus biopesticide to control the pest of corn Spodoptera frugiperda was analyzed. Kinetic variables such as maximum specific growth rate, cell productivity, mean rate of infection, as well as the mean rate of occlusion body production were determined during the infection of these cell-lines with the extracellular virus of the S. frugiperda nucleopolyhedrovirus (SfMNPV). The Sf9 cell-line resulted in better viral production results (5.0 x 10(8) OB/mL) than the Sf21 cell-line (2.5 x 10(8) OB/mL).
Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762) (Diptera: Culicidae) and Artemia salina (artemidae)
Authors: Arruda Eduardo José de , Rossi Ana Paula Leão , Porto Karla Rejane de Andrade , Oliveira Lincoln Carlos Silva de , Arakaki Andrea Haruko , Scheidt Gessiel Newton , Soccol Carlos Ricardo
Published: May 2010

This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24 h for Na2[EDTA-Cu(II)] and total mortality in 72 h for SAP-Na2[EDTA-Cu(II)].
BMI at Age 8 Years Is Influenced by the Type 2 Diabetes Susceptibility Genes HHEX-IDE and CDKAL1
Authors: Winkler Christiane , Bonifacio Ezio , Grallert Harald , Henneberger Lydia , Illig Thomas , Ziegler Anette-Gabriele
Published: May 2010

OBJECTIVE

To determine whether HHEX-IDE and CDKAL1 genes, which are associated with birth weight and susceptibility to type 2 diabetes, continue to influence growth during childhood.

RESEARCH DESIGN AND METHODS

BMI, weight, and height at age 8 years expressed as age- and sex-corrected standard deviation scores (SDS) against national reference data and single-nucleotide polymorphism genotyping of HHEX-IDE and CDKAL1 loci were analyzed in 646 prospectively followed children in the German BABYDIAB cohort. All children were singleton full-term births; 386 had mothers with type 1 diabetes, and 260 had fathers with type 1 diabetes and a nondiabetic mother.

RESULTS

Type 2 diabetes risk alleles at the HHEX-IDE locus were associated with reduced BMI-SDS at age 8 years (0.17 SDS per allele; P = 0.004). After stratification for birth weight, both HHEX-IDE and CDKAL1 risk alleles were associated with reduced BMI-SDS (0.45 SDS, P = 0.0002; 0.52 SDS, P = 0.0001) and weight-SDS (0.22 SDS, P = 0.04; 0.56 SDS, P = 0.0002) in children born large for gestational age (>90th percentile) but not children born small or appropriate for gestational age. Within children born large for gestational age, BMI and weight decreased with each additional type 2 diabetes risk allele (∼ −2 kg per allele; >8 kg overall). Findings were consistent in children of mothers with type 1 diabetes (P < 0.0001) and children of nondiabetic mothers (P = 0.008).

CONCLUSIONS

The type 2 diabetes susceptibility alleles at HHEX-IDE and CDKAL1 loci are associated with low BMI at age 8 years in children who were born large for gestational age.
Transient Inhibition of Transforming Growth Factor-β1 in Human Diabetic CD34+ Cells Enhances Vascular Reparative Functions
Authors: Bhatwadekar Ashay D. , Guerin E.P. , Jarajapu Yagna P.R. , Caballero Sergio , Sheridan Carl , Kent David , Kennedy Laurence , Lansang M. Cecilia , Ruscetti Frank W. , Pepine Carl J. , Higgins Paul J. , Bartelmez Stephen H. , Grant Maria B.
Published: May 2010

OBJECTIVE

Peripheral blood CD34+ cells from diabetic patients demonstrate reduced vascular reparative function due to decreased proliferation and diminished migratory prowess, largely resulting from decreased nitric oxide (NO) bioavailability. The level of TGF-β, a key factor that modulates stem cell quiescence, is increased in the serum of type 2 diabetic patients. We asked whether transient TGF-β1 inhibition in CD34+ cells would improve their reparative ability.

RESEARCH DESIGN AND METHODS

To inhibit TGF-β1 protein expression, CD34+ cells were treated ex vivo with antisense phosphorodiamidate morpholino oligomers (TGF-β1-PMOs) and analyzed for cell surface CXCR4 expression, cell survival in the absence of added growth factors, SDF-1-induced migration, NO release, and in vivo retinal vascular reparative ability.

RESULTS

TGF-β1-PMO treatment of diabetic CD34+ cells resulted in increased expression of CXCR4, enhanced survival in the absence of growth factors, and increased migration and NO release as compared with cells treated with control PMO. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34+ cells to injured acellular retinal capillaries was greater after TGF-β1-PMO treatment compared with control PMO–treated cells.

CONCLUSIONS

Transient inhibition of TGF-β1 may represent a promising therapeutic strategy for restoring the reparative capacity of dysfunctional diabetic CD34+ cells.
Sarcopenic Obesity: Prevalence and Association With Metabolic Syndrome in the Korean Longitudinal Study on Health and Aging (KLoSHA)
Authors: Lim Soo , Kim Jung Hee , Yoon Ji Won , Kang Seon Mee , Choi Sung Hee , Park Young Joo , Kim Ki Woong , Lim Jae Young , Park Kyong Soo , Jang Hak Chul
Published: May 2010

OBJECTIVE

We investigated the prevalence of sarcopenic obesity (SO) and its relationship with metabolic syndrome in a community-based elderly cohort in Korea.

RESEARCH DESIGN AND METHODS

In this study, 287 men and 278 women aged 65 or older were recruited. Sarcopenia was defined as the appendicular skeletal muscle mass (ASM) divided by height squared (Ht2) (kg/m2) or by weight (Wt) (%) of <1 SD below the sex-specific mean for young adults. Obesity was defined as a visceral fat area ≥100 cm2.

RESULTS

The prevalence of SO was 16.7% in men and 5.7% in women with sarcopenia defined by ASM/Ht2; however, it was 35.1% in men and 48.1% in women by ASM/Wt. Using ASM/Wt, the homeostasis model assessment of insulin resistance of subjects with SO was higher and they were at higher risk for metabolic syndrome (odds ratio [OR] 8.28 [95% CI 4.45–15.40]) than the obese (5.51 [2.81–10.80]) or sarcopenic group (2.64 [1.08–6.44]).

CONCLUSIONS

SO defined by ASM/Wt was more closely associated with metabolic syndrome than either sarcopenia or obesity alone.
Constructions of quotient algebras via triangular norms
Authors: Han Jeong , Kim Hee , Neggers J.
Published: May 2010

In this paper, properties of certain real-valued mappings Δ on binary systems X which satisfy versions of the triangle inequality are investigated. For example, via a quotient construction using Ker Δ = {x: Δ(x) = 0} it is shown that X/Ker Δ is a d-algebra if X is a d-algebra. In addition fuzzy versions of these triangular norms and their properties are considered as well. Finally boundedness conditions on Δ and a concept of magnitude are both introduced and some consequences are derived.
Random solution of random multivalued operator inclusions
Authors: Beg Ismat , Abbas Mujahid
Published: May 2010

Sufficient conditions for a random solution of random operator inclusions involving random multivalued operators satisfying a general contractive condition are obtained. A simultaneous random solution of the system of two random operator inclusions is also derived.