bluuebunny/crossref_metadata_2025 huggingface dataset:
Native Agarose Gel Electrophoresis of Multiprotein Complexes: Figure 1.
Authors: Kim Rosalind
Published: July 2011

INTRODUCTION

An important tool for the biochemist is the ability to analyze proteins in their native state. Electrophoresis of proteins and protein–protein complexes in native agarose gels using a horizontal gel apparatus is described here. The procedure is simple to set up, takes a short time to run, and avoids the use of toxic components. The gel is run in a submerged horizontal platform, with the wells positioned in the center of the gel. Proteins with a pI lower than the buffer pH carry a net negative charge and migrate toward the anode, whereas proteins with a pI higher than the buffer pH carry a positive charge and migrate toward the cathode. Proteins with different molecular weights and pI values can be tested, as can proteins that form complexes, whether they be two pure proteins forming a complex or a complex formed after incubating a pure protein with a crude extract. Once a complex is formed, it can be cut from the gel and the components can be isolated. This method does not replace isoelectric focusing (IEF) gels because it does not determine the pI of a protein, but it does facilitate the detection of protein–protein complexes and may give information on the protein’s charge at a defined pH.
Characterization of Helper-Dependent Adenoviral Vectors: Figure 1.
Authors: Palmer Donna J. , Ng Philip
Published: July 2011

INTRODUCTION

This protocol describes the characterization of helper-dependent adenoviral vectors (HDAd) with respect to physical titer, helper virus contamination, and genomic structure using standard molecular biology techniques. At a minimum, purified vector should be assessed for its physical titer, degree of helper virus contamination, and analysis of the HDAd genomic structure. If desired and depending on the application, additional characterization (i.e., endotoxin, sterility, adventitious agents, etc.) should be performed according to protocols established for E1-deleted Ad vectors.
Electrophysiological Recording from Drosophila Olfactory Sensilla
Authors: Benton Richard , Dahanukar Anupama
Published: July 2011

INTRODUCTION

The chemical senses smell and taste detect and discriminate an enormous diversity of environmental stimuli and provide fascinating but challenging models to investigate how sensory cues are represented in the brain. Important stimulus coding events occur in peripheral sensory neurons, which express specific combinations of chemosensory receptors with defined ligand-response profiles. These receptors convert ligand recognition into spatial and temporal patterns of neural activity, which are transmitted to and interpreted in central brain regions. Drosophila provides an attractive model to study chemosensory coding, because it possesses relatively simple peripheral olfactory and gustatory systems that display many organizational parallels to those of vertebrates. Moreover, virtually all of the peripheral chemosensory neurons are easily accessible for physiological analysis, because they are exposed on the surface of sensory organs in specialized sensory hairs called sensilla. In recent years, improvements in microscopy and instrumentation for electrode manipulation have opened up the much smaller Drosophila system to electrophysiological techniques, powerfully complementing many years of molecular genetic studies. As with most electrophysiological methods, there is probably no substitute for learning this technique directly from a laboratory in which it is already established. This protocol describes the basics of setting up the electrophysiology rig and stimulus delivery device, sample preparation, and how to perform and analyze recordings of odor-evoked activity from Drosophila olfactory sensilla.
Generation and Imaging of Brainbow Mice
Authors: Weissman Tamily A. , Sanes Joshua R. , Lichtman Jeff W. , Livet Jean
Published: July 2011

INTRODUCTION

This protocol describes how to generate Brainbow transgenes and mice, how to induce recombination in Brainbow mice with tamoxifen, and how to fix tissue samples from these animals. It also describes how to acquire multichannel images from Brainbow samples and use those images to digitally trace cellular contours and connections.
Labeling Mitochondria with Rhodamine 123
Authors: Chazotte Brad
Published: July 2011

INTRODUCTION

Rhodamine 123 is a cationic fluorescent dye that is used to specifically label respiring mitochondria. The dye distributes according to the negative membrane potential across the mitochondrial inner membrane. Loss of potential will result in loss of the dye and, therefore, the fluorescence intensity. The dye has been used to monitor mitochondrial function in living cells. This protocol describes the labeling of mitochondria with Rhodamine 123.
Labeling Mitochondria with TMRM or TMRE: Figure 1.
Authors: Chazotte Brad
Published: July 2011

INTRODUCTION

TMRM (tetramethylrhodamine methyl ester) or the related TMRE (tetramethylrhodamine ethyl ester) is extensively used for labeling and measuring the membrane potential (and the function) of mitochondria in living cells. Because of its optical and chemical properties, it has been one of the main dyes used for mitochondria studied with confocal microscopy to carry out time-resolved and spatially resolved analyses. Quantitative observation of mitochondrial membrane potential should be performed with confocal microscopy or spot photometry-based microscopy. This protocol describes labeling of mitochondria with TMRM or TMRE.
Immersion Freezing of Suspended Particles and Cells for Cryo-Electron Microscopy
Authors: Resch Guenter P. , Brandstetter Marlene , Königsmaier Lisa , Urban Edit , Pickl-Herk Angela M.
Published: July 2011

INTRODUCTION

Immersion freezing of thin aqueous specimens is an essential preparation technique for cryo-transmission electron microscopy (cryo-TEM), aiming to preserve fragile biological structures such as molecules and cells in their hydrated environment for a close-to-native visualization. For successful experiments, vitreous ice must be produced, surface contamination must be avoided, and, most important, the natural state of the structure must be preserved. This protocol describes immersion freezing of biological samples, such as purified protein complexes, viruses, liposomes, synthetic cytoskeletal filaments, isolated organelles, or small cells suspended in an aqueous solution, using the new Leica “EM GP” grid plunger. It includes a discussion of issues of general importance for cryo-EM, such as the properties of the sample and the pretreatment of the specimen carrier. It also provides details on how to make the most of the special features of this instrument to obtain good specimens and reproducible results. Troubleshooting issues concerning the operation of the GP in particular, as well as common problems in immersion freezing encountered on manual and semiautomatic instruments, are addressed.
Constructing a Microinjection Chamber for Zebrafish Eggs
Authors: Godinho Leanne
Published: July 2011

INTRODUCTION

In the last two decades, the small tropical freshwater-dwelling zebrafish has emerged as a popular model for developmental biologists. The exceptional optical accessibility of zebrafish embryos coupled with the ability to use genetic tools to indelibly tag cells have been exploited to watch developmental events as they unfold. Moreover, because zebrafish are vertebrates, the knowledge gained through such studies is broadly applicable. This protocol describes the construction of a microinjection chamber for zebrafish eggs. Several microinjection chambers can be made, can be stored at 4°C, and can be used for several weeks until the injection trenches become damaged through repeated use and/or mold begins to grow on the agarose.
Imaging Zebrafish Development
Authors: Godinho Leanne
Published: July 2011

INTRODUCTION

In the last two decades, the small tropical freshwater-dwelling zebrafish has emerged as a popular model for developmental biologists. The exceptional optical accessibility of zebrafish embryos coupled with the ability to use genetic tools to indelibly tag cells have been exploited to watch developmental events as they unfold. Moreover, because zebrafish are vertebrates, the knowledge gained through such studies is broadly applicable. This protocol describes the procedure for imaging zebrafish development. Once zebrafish cells have been labeled with fluorescent molecules or stained with fluorescent dye, the developmental processes of interest can be analyzed using a wide variety of live imaging techniques, such as wide-field microscopy, confocal microscopy, or multiphoton microscopy.
Immersion Freezing of Biological Specimens: Rationale, Principles, and Instrumentation
Authors: Resch Guenter P. , Brandstetter Marlene , Pickl-Herk Angela M. , Königsmaier Lisa , Wonesch Veronika I. , Urban Edit
Published: July 2011

INTRODUCTION

Cryo-transmission electron microscopy (cryo-TEM) allows the visualization of biological specimens within their native, hydrated environment at nanometer resolution. To prevent the formation of destructive ice crystals, an extremely high cooling rate has to be achieved in the freezing process. For samples that are inherently thin enough, ranging from macromolecules to peripheral parts of spread cells, this can be accomplished by plunging the sample into a cryogen. This approach, known as “immersion freezing,” is an essential preparation technique in structural, molecular, and cell biology. In this article, we discuss the advantages of cryo-EM, the scope of specimens that can be visualized using this technique, the method of immersion freezing, and the instrumentation available. In particular, we focus on the new semiautomatic immersion freezer by Leica Microsystems (“EM GP”).
STENOFOLIARegulates Blade Outgrowth and Leaf Vascular Patterning inMedicago truncatulaandNicotiana sylvestris
Authors: Tadege Million , Lin Hao , Bedair Mohamed , Berbel Ana , Wen Jiangqi , Rojas Clemencia M. , Niu Lifang , Tang Yuhong , Sumner Lloyd , Ratet Pascal , McHale Neil A. , Madueño Francisco , Mysore Kirankumar S.
Published: July 2011

Dicot leaf primordia initiate at the flanks of the shoot apical meristem and extend laterally by cell division and cell expansion to form the flat lamina, but the molecular mechanism of lamina outgrowth remains unclear. Here, we report the identification of STENOFOLIA (STF), a WUSCHEL-like homeobox transcriptional regulator, in Medicago truncatula, which is required for blade outgrowth and leaf vascular patterning. STF belongs to the MAEWEST clade and its inactivation by the transposable element of Nicotiana tabacum cell type1 (Tnt1) retrotransposon insertion leads to abortion of blade expansion in the mediolateral axis and disruption of vein patterning. We also show that the classical lam1 mutant of Nicotiana sylvestris, which is blocked in lamina formation and stem elongation, is caused by deletion of the STF ortholog. STF is expressed at the adaxial–abaxial boundary layer of leaf primordia and governs organization and outgrowth of lamina, conferring morphogenetic competence. STF does not affect formation of lateral leaflets but is critical to their ability to generate a leaf blade. Our data suggest that STF functions by modulating phytohormone homeostasis and crosstalk directly linked to sugar metabolism, highlighting the importance of coordinating metabolic and developmental signals for leaf elaboration.
The Plant-Specific Actin Binding Protein SCAB1 Stabilizes Actin Filaments and Regulates Stomatal Movement inArabidopsis
Authors: Zhao Yang , Zhao Shuangshuang , Mao Tonglin , Qu Xiaolu , Cao Wanhong , Zhang Li , Zhang Wei , He Liu , Li Sidi , Ren Sulin , Zhao Jinfeng , Zhu Guoli , Huang Shanjin , Ye Keqiong , Yuan Ming , Guo Yan
Published: July 2011

Microfilament dynamics play a critical role in regulating stomatal movement; however, the molecular mechanism underlying this process is not well understood. We report here the identification and characterization of STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1 (SCAB1), an Arabidopsis thaliana actin binding protein. Plants lacking SCAB1 were hypersensitive to drought stress and exhibited reduced abscisic acid-, H2O2-, and CaCl2-regulated stomatal movement. In vitro and in vivo analyses revealed that SCAB1 binds, stabilizes, and bundles actin filaments. SCAB1 shares sequence similarity only with plant proteins and contains a previously undiscovered actin binding domain. During stomatal closure, actin filaments switched from a radial orientation in open stomata to a longitudinal orientation in closed stomata. This switch took longer in scab1 plants than in wild-type plants and was correlated with the delay in stomatal closure seen in scab1 mutants in response to drought stress. Our results suggest that SCAB1 is required for the precise regulation of actin filament reorganization during stomatal closure.
Invasion front‐specific expression and prognostic significance of microRNA in colorectal liver metastases
Authors: Kahlert Christoph , Klupp Fee , Brand Karsten , Lasitschka Felix , Diederichs Sven , Kirchberg Johanna , Rahbari Nuh , Dutta Shamik , Bork Ulrich , Fritzmann Johannes , Reissfelder Christoph , Koch Moritz , Weitz Juergen
Published: July 2011

The tumor edge of colorectal cancer and its adjacent peritumoral tissue is characterized by an invasion front‐specific expression of genes that contribute to angiogenesis or epithelial‐to‐mesenchymal transition. Dysregulation of these genes has a strong impact on the invasion behavior of tumor cells. However, the invasion front‐specific expression of microRNA (miRNA) still remains unclear. Therefore, the aim of the present study was to investigate miRNA expression patterns at the invasion front of colorectal liver metastases. Laser microdissection of colorectal liver metastases was performed to obtain separate tissue compartments from the tumor center, tumor invasion front, liver invasion front and pure liver parenchyma. Microarray expression analysis revealed 23 miRNA downregulated in samples from the tumor invasion front with respect to the same miRNA in the liver, the liver invasion front or the tumor center. By comparing samples from the liver invasion front with samples from pure liver parenchyma, the tumor invasion front and the tumor center, 13 miRNA were downregulated. By quantitative RT‐PCR, we validated the liver invasion front‐specific downregulation of miR‐19b, miR‐194, let‐7b and miR‐1275 and the tumor invasion front‐specific downregulation of miR‐143, miR‐145, let‐7b and miR‐638. Univariate analysis demonstrated that enhanced expression of miR‐19b and miR‐194 at the liver invasion front, and decreased expression of let‐7 at the tumor invasion front, is an adverse prognostic marker of tumor recurrence and overall survival. In conclusion, the present study suggests that invasion front‐specific downregulation of miRNA in colorectal liver metastases plays a pivotal role in tumor progression. (Cancer Sci 2011; 102: 1799–1807)
Do wood‐grazing fishes partition their niche?: morphological and isotopic evidence for trophic segregation in Neotropical Loricariidae
Authors: Lujan Nathan K. , German Donovan P. , Winemiller Kirk O.
Published: July 2011

1. Morphic detritus, including coarse particulate organic matter such as terrestrial tree leaves and wood, is consumed by few fishes in temperate stream systems but is ingested by abundant and diverse groups of specialized fishes in tropical rivers; physiological assimilation and partitioning of morphic detritus by fishes remain poorly understood.

2. This study examines seven species of Neotropical suckermouth‐armored catfishes (Loricariidae) that live among and feed on coarse woody debris. Five species represent two unrelated evolutionary lineages showing convergent morphological specializations for gouging into and eating wood, small particles of which fill their guts. Two morphologically distinct species unrelated to wood‐eaters and to each other forage along the surface of wood.

3. We examined six jaw functional morphological characteristics of each loricariid species as well as C and N stable isotope ratios of blood plasma, red blood cells and fin tissue of three wood‐eating species and muscle tissues of all seven species. Consumer isotopic signatures were compared among species and with isotopic signatures of potential food resources, including biofilm, seston and both bulk wood and holocellulose extracted from bulk wood.

4. Wood‐eating species had robust jaws specialized for gouging wood, δ13C signatures consistent with assimilation of cellulosic wood carbon (not bulk wood carbon or lignin) and elevated δ15N values (>5·8‰) relative to wood that were consistent with assimilation of N from intermediate microbial decomposers in the environment rather than direct assimilation of N from wood or from endosymbiotic N‐fixers. Two non‐wood‐eating species occupied divergent regions of jaw functional morphospace, and isotopic signatures were consistent with assimilation of C from biofilm and seston, respectively, and N from enriched sources such as microbes, macroinvertebrates or seston.

5. Food resources associated with the surfaces of coarse woody debris in Neotropical rivers are partitioned among at least three guilds of loricariid consumers with divergent jaw morphologies specialized for wood gouging, surface grazing and macroinvertebrate probing. Direct consumption of morphic detritus by specialized Neotropical fishes constitutes a potentially important but poorly understood component of detritus processing and nutrient cycling in tropical rivers.
‘X’ marks the spot: The possible benefits of nectar guides to bees and plants
Authors: Leonard Anne S. , Papaj Daniel R.
Published: July 2011

1. Many floral displays are visually complex, transmitting multi‐coloured patterns that are thought to direct pollinators to nectar rewards. These ‘nectar guides’ may be mutually beneficial, if they reduce pollinators’ handling time, leading to an increased visitation rate and promoting pollen transfer. Yet, many details regarding how floral patterns influence foraging efficiency are unknown, as is the potential for pollinator learning to alter this relationship.

2. We compared the responses of bumblebee (Bombus impatiens Cresson) foragers to artificial flowers that either possessed or lacked star‐like patterns. By presenting each bee with two different foraging scenarios (patterned flowers rewarding/plain flowers unrewarding, plain flowers rewarding/patterned flowers unrewarding) on different days, we were able to assess both short‐ and long‐term effects of patterns on bee foraging behaviour.

3. Bees discovered rewards more quickly on patterned flowers and were less likely to miss the reward, regardless of whether corollas were circular or had petals. Nectar guides’ effect on nectar discovery was immediate (innate) and persisted even after experience, although nectar discovery itself also had a learned component. We also found that bees departed patterned flowers sooner after feeding. Finally, when conditions changed such that flowers no longer provided a reward, bees visited the now‐unrewarding flowers more persistently when they were patterned.

4. On the time‐scale of a single foraging bout, our results provide some of the first data on how pollinators learn to forage efficiently using this common floral trait. Our bees’ persistent response to patterned flowers even after rewards ceased suggests that, rather than being consistently mutually beneficial to plant and pollinator, nectar guide patterns can at times promote pollen transfer for the plant at the expense of a bee’s foraging success.
Efficiency of novel iron microencapsulation techniques: fortification of milk
Authors: Abbasi Soleiman , Azari Sara
Published: July 2011

Effects of iron/lipid ratio, Tween 80 and polyglycerol monostearate (PGMS)/iron ratio on encapsulation efficiency (EE) of liposome and fatty acid esters (FAE) methods were investigated. Then, microencapsulated irons were added to pasteurised milk, and during storage, stability, colour and sensory characteristics were evaluated. Regarding liposome method, the highest EE (85.5%) was found at iron/lipid ratio and Tween 80 of 0.04 and 5%, respectively. In terms of FAE, the highest EE (81.8%) was obtained at PGMS/iron salt ratio of 15:1. Regarding sensory properties, the differences were insignificant (P > 0.05) except metallic taste and smell (P < 0.05). Moreover, milk fortified with FAE‐microencapsulated irons showed highest similarity to control particularly at low concentration (7 mg L−1). In general, the FAE technique was found very efficient, low cost, simple, rapid and practical for microencapsulation of iron in either forms as well as fortification of pasteurised milk.
Efficacy of a non‐drilling approach to manage non‐cavitated dentin occlusal caries in primary molars: a 12‐month randomized controlled clinical trial
Authors: BORGES BONIEK C. D. , De SOUZA BEZERRA ARAÚJO RAPHAEL F. , DANTAS RACHEL F. , De ARAÚJO LUCENA ALLISSON , De ASSUNÇÃO PINHEIRO ISAUREMI V.
Published: July 2011

International Journal of Paediatric Dentistry 2011; 22: 44–51

Background.  Despite the efficacy of non‐drilling approaches to manage non‐cavitated dentin occlusal lesions (NCDOL) in permanent teeth, there is no data validating this type of therapy in the primary dentition.

Aim.  To compare the efficacy of a traditional fissure sealant in managing NCDOL in primary molars.

Design.  This study is a randomized controlled clinical trial with a split‐mouth design. Thirty schoolchildren with two NCDOL were selected and divided into two groups. The experimental group received a resin‐based fissure sealant, whereas the control group was treated with a conventional composite resin. Treatment efficacy was evaluated after 1 year by means of clinical and radiographic examinations.

Results.  The two treatment modalities were found to be similarly effective in managing DONCL in primary molars.

Conclusion.  For the management of non‐cavitated dentin occlusal caries in primary teeth, the invasive approach can be replaced with non‐drilling fissure sealing techniques.
Relative role of deterministic and stochastic determinants of soil animal community: a spatially explicit analysis of oribatid mites
Authors: Caruso Tancredi , Taormina Mauro , Migliorini Massimo
Published: July 2011

1. Ecologists are debating the relative role of deterministic and stochastic determinants of community structure. Although the high diversity and strong spatial structure of soil animal assemblages could provide ecologists with an ideal ecological scenario, surprisingly little information is available on these assemblages.

2. We studied species‐rich soil oribatid mite assemblages from a Mediterranean beech forest and a grassland. We applied multivariate regression approaches and analysed spatial autocorrelation at multiple spatial scales using Moran’s eigenvectors. Results were used to partition community variance in terms of the amount of variation uniquely accounted for by environmental correlates (e.g. organic matter) and geographical position. Estimated neutral diversity and immigration parameters were also applied to a soil animal group for the first time to simulate patterns of community dissimilarity expected under neutrality, thereby testing neutral predictions.

3. After accounting for spatial autocorrelation, the correlation between community structure and key environmental parameters disappeared: about 40% of community variation consisted of spatial patterns independent of measured environmental variables such as organic matter. Environmentally independent spatial patterns encompassed the entire range of scales accounted for by the sampling design (from tens of cm to 100 m). This spatial variation could be due to either unmeasured but spatially structured variables or stochastic drift mediated by dispersal. Observed levels of community dissimilarity were significantly different from those predicted by neutral models.

4. Oribatid mite assemblages are dominated by processes involving both deterministic and stochastic components and operating at multiple scales. Spatial patterns independent of the measured environmental variables are a prominent feature of the targeted assemblages, but patterns of community dissimilarity do not match neutral predictions. This suggests that either niche‐mediated competition or environmental filtering or both are contributing to the core structure of the community. This study indicates new lines of investigation for understanding the mechanisms that determine the signature of the deterministic component of animal community assembly.
Plant species identity and arbuscular mycorrhizal status modulate potential nitrification rates in nitrogen‐limited grassland soils
Authors: Veresoglou Stavros D. , Sen Robin , Mamolos Andreas P. , Veresoglou Demetrios S.
Published: July 2011

1. Arbuscular mycorrhizal (AM) fungi and ammonia oxidizers (AO) represent key soil microbial groups regulating nitrogen (N) cycling in terrestrial ecosystems. Both utilize soil ammonium‐N reserves for N assimilation, whilst the latter, through autotrophic nitrification, drive ammonia oxidation to highly mobile nitrate‐N.

2. An incompatible interaction between root symbiotic AM fungi and AO was hypothesized and evaluated in plant–species‐rich, N‐limited Mediterranean grassland soils. Such an outcome would be manifested in a negative relationship between plant mycotrophy and local soil potential nitrification rates (PNR), a standard functional measure of ammonia‐oxidizing activity in soils.

3. In three independent mesocosm experiments, grassland soils that supported monocultures of mycotrophic, as opposed to weakly and non‐mycotrophic, plants exhibited significantly lower PNR. Under field conditions in a fourth experiment, we verified that soils from stands of weakly mycotrophic Agrostis capillaris sustained higher PNR than counterparts supporting highly mycorrhizal Prunella vulgaris and Fragaria vesca.

4. Discussion of mycotrophy‐related modulation of AO activity centres on whether the observed relationships highlight evidence for either direct competition or a functionally important example of plant–microbial allelopathy.

5. Synthesis. Substantial evidence has been presented confirming (i) plant species identity‐related regulation of PNR and (ii) negative relationships between plant mycotrophy and plant species‐mediated impact on PNR in N‐limited Mediterranean grassland soils. Likely mechanisms (i.e. competition and/or allelopathy) that underpin this functionally significant plant–microbe–soil relationship controlling the fate of ammonium‐N require urgent elucidation in N‐deficient ecosystems.
Three methods for estimating days of hospitalization because of hospital‐acquired infection: a comparison
Authors: Barbaro Silvana , De Rosa Francesco G. , Charrier Lorena , Silvestre Carlo , Lovato Emanuela , Gianino Maria M.
Published: July 2011

Objectives  The objective of this study is to compare the three methods internationally used for estimating days of hospitalization attributable to hospital infections by applying them to the same population. The methods are: (1) unmatched comparison group; (2) matched control method‐based; and (3) Appropriateness Evaluation Protocol method. A study of the prevalence of infections was performed among patients during hospitalization for an ordinary single sampling department. The survey was completed within eight working days between 15 and 24 October 2007. All patients admitted at least 24 hours to the survey day in each department were included in the study, as well as patients discharged/transferred to another hospital or department. During the prevalence study 621 patients were observed, 70 of which with infection (equal to 11.27%).

Method  The 70 uninfected patients needed for comparison using method 1 were selected through a procedure based on propensity score on demographic variables and clinical trials of patients. The Shapiro–Wilk test was used to verify the normality of quantitative variables. In comparing the three methods Kruskall–Wallis test was used (alpha = 0.05), while comparisons between pairs of methods were performed with the Mann–Whitney test (alpha = 0.017).

Results  Estimation results of recovery days with infection using the three comparison tests showed that there is a statistically significant difference between the three methods (P = 0.016) and there is a significant difference between 1 versus 3 (P = 0.013) and between 2 and 3 (P = 0.017), whereas between 1 and 2 no difference was found (P = 0.82).

Conclusion  In conclusion, the three methods are not showing the same estimations and thus may not be exchangeable.
A Bold View of the Lactating Brain: Functional Magnetic Resonance Imaging Studies of Suckling in Awake Dams
Authors: Febo M.
Published: July 2011

Functional magnetic resonance imaging (fMRI) has been used to investigate the responsiveness of the maternal rat brain to pup‐suckling under various experimental paradigms. Our research employing the lactating rat model has explored the cortical sensory processing of pup stimuli and the effect of suckling on the brain’s reward system. Suckling was observed to increase blood‐oxygen‐level‐dependent (BOLD) signal intensity in the midbrain, striatum and prefrontal cortex, which are areas that receive prominent dopaminergic inputs. The BOLD activation of the reward system occurs in parallel with the activation of extensive cortical sensory areas. The observed regions include the olfactory cortex, auditory cortex and gustatory cortex, and could correspond to cortical representations of pup odours, vocalisations and taste that are active during lactation. Activation patterns within reward regions are consistent with past research on maternal motivation and we explore the possibility that exposure to drugs of abuse might be disruptive of maternal neural responses to pups, particularly in the prefrontal cortex. Our ongoing fMRI studies support and extend past research on the maternal rat brain and its functional neurocircuitry.
Oestrogen Signalling and Neuroprotection in Cerebral Ischaemia
Authors: Brann D. , Raz L. , Wang R. , Vadlamudi R. , Zhang Q.
Published: July 2011

17β‐Oestradiol (E2) is an important hormone signal that regulates multiple tissues and functions in the body. This review focuses on the neuroprotective actions of E2 in the brain against cerebral ischaemia and the potential underlying mechanisms. A particular focus of the review will be on the role of E2 to attenuate NADPH oxidase activation, superoxide and reactive oxygen species generation and reduce oxidative stress in the ischaemic brain as a potentially key neuroprotective mechanism. Evidence of a potential novel role of extranuclear oestrogen receptors in mediating E2 signalling and neuroprotective actions is also discussed. An additional subject is the growing evidence indicating that periods of long‐term oestrogen deprivation, such as those occurring after menopause or surgical menopause, may lead to loss or attenuation of E2 signalling and neuroprotective actions in the brain, as well as enhanced sensitivity of the hippocampus to ischaemic stress damage. These findings have important implications with respect to the ‘critical period hypothesis’, which proposes that oestrogen replacement must be initiated at peri‐menopause in humans to exert its beneficial cardiovascular and neural effects. The insights gained from these various studies will prove valuable for guiding future directions in the field.
Oestradiol Regulates β‐Catenin‐Mediated Transcription in Neurones
Authors: Wandosell F. , Varea O. , Arevalo M. A. , Garcia‐Segura L. M.
Published: July 2011

Oestradiol acts in the brain by multiple mechanisms, including the regulation of transcriptional activity through classical oestrogen receptors, α and β, and by the activation of membrane/cytoplasm‐initiated signalling cascades. In neuroblastoma cells, primary neurones in culture and in the brain in vivo, oestradiol activates the phosphoinositide 3‐kinase/Akt/glycogen synthase kinase 3 signalling pathway by a mechanism involving oestrogen receptor α. Through this pathway, oestradiol regulates the stability of β‐catenin, induces the translocation of β‐catenin to the cell nucleus and regulates β‐catenin‐mediated transcription through the T cell factor/DNA complex. Genomic analyses in neuroblastoma cells have revealed that the set of genes regulated by oestradiol through β‐catenin is not identical to that regulated by the Wnt signalling pathway, revealing a new mechanism for oestradiol signalling in neurones.
Beyond the genome: recent advances in Toxoplasma gondii functional genomics
Authors: ADOMAKO‐ANKOMAH Y. , WIER G. M. , BOYLE J. P.
Published: July 2011

Recent years have witnessed an explosion in the amount of genomic information available for Toxoplasma gondii and other closely related pathogens. These data, many of which have been made publicly available prior to publication, have facilitated a wide variety of functional genomics studies. In this review, we provide a brief overview of existing database tools for querying the Toxoplasma genome and associated genome‐wide data and review recent publications that have been facilitated by these data. Topics covered include strain comparisons and quantitative trait loci mapping, gene expression analyses during the cell cycle as well as during parasite differentiation, and proteomics.
Immunologically based control strategies for ostertagiosis in cattle: where do we stand?
Authors: RINALDI M. , GELDHOF P.
Published: July 2011

Ostertagia ostertagi is one of the most important gastrointestinal parasites infecting millions of cattle in temperate climate areas. Because infection leads to significant losses in productivity, farmers are pushed, because of the on‐going intensification of the livestock production systems, to frequently administer anthelmintics to minimize the exposure of their animals to this parasite. However, whether such approach is sustainable in the long term, especially in an era of emerging drug resistance and global climatic changes, is still a matter of debate. Immunological control of worm infections through vaccination is often put forward as the most rational and cost‐effective alternative for anthelmintics to control helminth infections. However, the development of an immunologically based control strategy requires a thorough knowledge of the host–parasite interactions, the immune responses involved and the biology of the parasite itself. The aim of this review is to consolidate information available in these areas, specifically for O. ostertagi, and identify some critical gaps in our current knowledge.
Unstructured treatment interruption of antiretroviral therapy in clinical practice: a systematic review
Authors: Kranzer Katharina , Ford Nathan
Published: July 2011

Objective  To characterize the frequency, reasons, risk factors, and consequences of unstructured anti‐retroviral treatment interruptions.

Method  Systematic review.

Results  Seventy studies were included. The median proportion of patients interrupting treatment was 23% for a median duration of 150 days. The most frequently reported reasons for interruptions were drug toxicity, adverse events, and side‐effects; studies from developing countries additionally cited treatment costs and pharmacy stock‐outs as concerns. Younger age and injecting drug use was a frequently reported risk factor. Other risk factors included CD4 count, socioeconomic variables, and pharmacy stock outs. Treatment interruptions increased the risk of death, opportunistic infections, virologic failure, resistance development, and poor immunological recovery. Proposed interventions to minimize interruptions included counseling, mental health services, services for women, men, and ethnic minorities. One intervention study found that the use of short message service reminders decrease the prevalence of treatment interruption from 19% to 10%. Finally, several studies from Africa stressed the importance of reliable and free access to medication.

Conclusion  Treatment interruptions are common and contribute to worsening patient outcomes. HIV/AIDS programmes should consider assessing their causes and frequency as part of routine monitoring. Future research should focus on evaluating interventions to address the most frequently reported reasons for interruptions.
Increased HAS2‐driven hyaluronic acid synthesis in shar‐pei dogs with hereditary cutaneous hyaluronosis (mucinosis)
Authors: Docampo María José , Zanna Giordana , Fondevila Dolors , Cabrera Jennifer , López‐Iglesias Carmen , Carvalho Andrea , Cerrato Santiago , Ferrer Lluís , Bassols Anna
Published: July 2011

The Chinese shar‐pei dog is known for its distinctive feature of wrinkled and thickened skin, defined as primary or hereditary cutaneous mucinosis. In a recent report, we identified the mucinous material deposited in the shar‐pei skin as the polysaccharide hyaluronan (HA). In the present work, the molecular and cellular mechanisms underlying this phenotype have been identified in dermal fibroblasts isolated from shar‐pei dogs. The production of HA, which appeared to be mainly associated with cell membrane protrusions and also intracellular, was higher in shar‐pei fibroblasts than in control cells. The HA accumulation is related to a higher mRNA expression of the isoform HAS2 of the HA‐synthesizing enzyme family, hyaluronan synthases (HAS). The higher expression of HAS2 in shar‐pei fibroblasts was confirmed at the protein level. The other HAS isoenzymes, HAS1 and HAS3, and the HA‐degrading enzymes, Hyal1 and Hyal2, were not differentially expressed in shar‐pei fibroblasts compared with cells from control dogs. Fibroblasts from shar‐pei dogs and from control dogs are morphologically different as observed by transmission electron microscopy. Scanning electron microscopy revealed a large number of cellular protrusions with associated globular deposits. Electron microscopy after labelling with biotinylated HA‐binding protein confirmed an increased HA content in shar‐pei fibroblasts, which could be localized in several subcellular structures. The authors propose the name hereditary cutaneous hyaluronosis (HCH) for affected dogs, because it better defines the cutaneous mucinosis of shar‐pei dogs.
Successful treatment of a novel generalized variant of canine discoid lupus erythematosus with oral hydroxychloroquine
Authors: Oberkirchner Ursula , Linder Keith E. , Olivry Thierry
Published: July 2011

Discoid lupus erythematosus (DLE) is a common canine autoimmune disease that usually manifests as a localized ulcerative and scarring nasal dermatitis. We report herein a generalized variant of canine DLE successfully treated with the antimalarial immunomodulator hydroxychloroquine (HCQ). A 9‐year‐old hairless Chinese crested dog was presented with annular and polycyclic hyperpigmented and scaly skin lesions with central erosions, hypopigmentation and/or scarring on the trunk, neck and lateral extremities. Associated systemic signs were not seen. The clinical diagnosis of generalized DLE was supported by the demonstration of lymphocyte‐rich interface dermatitis with epidermal atrophy and dermo‐epidermal deposition of immunoglobulins and activated complement. As for human DLE, treatment was initiated with HCQ at 5 mg/kg once daily along with 2 weeks of 0.1% tacrolimus ointment and restriction of sun exposure. Over the following year, complete remission was maintained with HCQ at 5 mg/kg orally once daily with the exception of three relapses; two occurred during treatment induction and the third arose when the frequency of HCQ administration was reduced to every other day. Disease flares were controlled with 0.1% tacrolimus ointment alternating with 0.1% prednicarbate cream once daily for 5–10 days. Altogether, adverse drug events were not seen with this regimen. In summary, clinically, histologically and immunologically, this dog’s disease mirrored the generalized discoid variant of chronic cutaneous lupus erythematosus of humans. The apparent benefit of HCQ, its safety and low cost warrant future investigations of its use for treatment of canine cutaneous lupus variants.
What can we learn from old microdeletion syndromes using array‐CGH screening?
Authors: Mosca‐Boidron A L , Bouquillon S , Faivre L , Callier P , Andrieux J , Marle N , Bonnet C , Vincent‐Delorme C , Berri M , Plessis G , Manouvrier‐Hanu S , Dieux‐Coeslier A , Thauvin‐Robinet C , Pipiras E , Delahaye A , Payet M , Ragon C , Masurel‐Paulet A , Questiaux E , Benzacken B , Jonveaux P , Mugneret F , Holder‐Espinasse M
Published: July 2011

Mosca‐Boidron AL, Bouquillon S, Faivre L, Callier P, Andrieux J, Marle N, Bonnet C, Vincent‐Delorme C, Berri M, Plessis G, Manouvrier‐Hanu S, Dieux‐Coeslier A, Thauvin‐Robinet C, Pipiras E, Delahaye A, Payet M, Ragon C, Masurel‐Paulet A, Questiaux E, Benzacken B, Jonveaux P, Mugneret F, Holder‐Espinasse M. What can we learn from old microdeletion syndromes using array‐CGH screening?

Most microdeletion syndromes identified before the implementation of array‐comparative genomic hybridization (array‐CGH) were presumed to be well‐defined clinical entities. However, the introduction of whole‐genome screening led not only to the description of new syndromes but also to the recognition of a broader spectrum of features for well‐known syndromes. Here, we report on 10 patients presenting with mental retardation associated with atypical features not suggestive of a known microdeletion and a normal standard karyotype. Array‐CGH analyses revealed five microdeletions in the DiGeorge region, three microdeletions in the Williams‐Beuren region and two microdeletions in the Smith‐Magenis region. Reevaluation in these patients confirmed that the diagnosis remained difficult on clinical grounds and emphasized that well‐known genomic disorders can have a phenotype that is heterogeneous and more variable than originally thought. The widespread use of array‐CGH shows that such patients may be more readily achieved on the basis of genotype rather than phenotype.
‘Rediscovery’ revised – the cooperation of Erich and Armin von Tschermak‐Seysenegg in the context of the ‘rediscovery’ of Mendel’s laws in 1899–19011
Authors: Simunek M. , Hoßfeld U. , Wissemann V.
Published: July 2011

The ‘rediscovery’ of Mendel’s laws in 1900 is seen as a turning point in modern research on heredity and genetics. In the first half of the 20th century it was generally held that the ‘rediscovery’ was made several times, independently, and in a parallel fashion by three European botanists (Carl Correns, Hugo de Vries and Erich von Tschermak‐Seysenegg). Since the 1950s, however, serious questions have arisen concerning both the chronology and the specific conceptual contribution of the scientists involved. Not only the independence but also parallelism was analysed in the context of individual research programmes of all three of these scholars. The youngest of them, Austrian botanist Erich von Tschermak‐Seysenegg, was excluded from the rank of ‘rediscoverers’. It is the aim of this paper to use new archival evidence and add important facts both to the chronology and conceptual framework of Erich von Tschermak‐Seysenegg’s work. An entirely new aspect is added by identifying his older brother, the physiologist Armin von Tschermak‐Seysenegg (1870–1952), as a significant spiritus movens of the events of 1900 and 1901. A selected part of their correspondence, covering the period from 13 March 1898 until 19 November 1901, is made available in transcriptions.
Association of 8q24.21 loci with the risk of colorectal cancer: A systematic review and meta‐analysis
Authors: Haerian Monir Sadat , Baum Larry , Haerian Batoul Sadat
Published: July 2011

Background and Aim:  Recent genome‐wide association studies of colorectal cancer (CRC) have identified rs6983267 and trs10505477 polymorphisms as key loci in the 8q24 region to be associated with CRC. In the present study, we performed a meta‐analysis to determine whether these loci are risk factors for susceptibility to CRC.

Methods:  We meta‐analyzed the 22 included studies (47 003 cases and 45 754 controls) that evaluated the association of rs6983267 and trs10505477 with CRC under alternative genetic models.

Results:  A meta‐analysis of the pooled data showed allelic and genotypic association of the rs6983267 polymorphism with CRC risk in Asians, Europeans, and European‐Americans. A subanalysis of the US studies showed negative results in the studies with non‐identified ethnicity of the patients. A meta‐analysis of included studies of rs10505477 polymorphisms identified allelic and genotypic associations with CRC risk in the US patients. A further meta‐analysis of the US studies demonstrated positive results in the studies with non‐identified ethnicity of the samples.

Conclusion:  Our data suggested that the rs6983267 G > T polymorphism is a risk factor for CRC in Asians, Europeans, and Americans with European ancestry.
Detection of single‐nucleotide polymorphisms in the intron 9 region of the nucleotide oligomerization domain‐1 gene in ulcerative colitis patients of North India
Authors: Verma Ravi , Ahuja Vineet , Paul Jaishree
Published: July 2011

Background and Aim:  The nucleotide‐binding oligomerization domain‐1 (NOD1) gene encodes a pattern recognition receptor that senses pathogens. NOD1/caspase recruitment domain (CARD4) signaling leads to the activation of nuclear factor‐kB, and plays an important role in innate immunity. Certain polymorphisms and mutations in NOD1/CARD4 might result in a dysfunctional innate immune response during bacterial recognition, which might have direct implications in inflammatory bowel disease (IBD) pathogenesis.

Methods:  We carried out a systemic analysis for the presence of polymorphic variants in the intron 9 region of the leucine‐rich repeat (LRR) domain encompassing the exon–intron boundaries of the NOD1 gene. To detect unknown single‐nucleotide polymorphisms, we used the denaturing high‐performance liquid chromatography (DHPLC) screening technique and validated our data by restriction fragment length polymorphism and direct sequencing.

Result:  Genotype and allele frequencies showed significant differences in their distribution. The mutations discriminating alleles in the intron 9 region of the LRR domain of the NOD1 gene were correctly predicted by DHPLC technique and statistically verified in IBD and non‐IBD individuals. Of the seven mutations detected, only four showed a significant association with disease activity. Mutations detected earlier in the exon 6 region of NOD1 were also used for the haplotype analysis. The GTTG haplotype was found to be significantly overrepresented in ulcerative colitis (UC) patients, as compared to the controls (P = 3.3726E−6).

Conclusion:  Our study has revealed a polymorphism association in the LRR domain of the NOD1 gene with the severity of UC disease. This might be due to disruption of the LRR region critical for NOD1‐mediated bacterial sensing. A gene‐wide, haplotype‐based approach shows that GTTG haplotype carriers are overrepresented in UC patients, and that could increase the risk of the disease.