bluuebunny/crossref_metadata_2025 huggingface dataset:
The Met receptor tyrosine kinase prevents zebrafish primary motoneurons from expressing an incorrect neurotransmitter
Authors: Tallafuss Alexandra , Eisen Judith S
Published: July 2008

Background

Expression of correct neurotransmitters is crucial for normal nervous system function. How neurotransmitter expression is regulated is not well-understood; however, previous studies provide evidence that both environmental signals and intrinsic differentiation programs are involved. One environmental signal known to regulate neurotransmitter expression in vertebrate motoneurons is Hepatocyte growth factor, which acts through the Met receptor tyrosine kinase and also affects other aspects of motoneuron differentiation, including axonal extension. Here we test the role of Met in development of motoneurons in embryonic zebrafish.

Results

We found that met is expressed in all early developing, individually identified primary motoneurons and in at least some later developing secondary motoneurons. We used morpholino antisense oligonucleotides to knock down Met function and found that Met has distinct roles in primary and secondary motoneurons. Most secondary motoneurons were absent from met morpholino-injected embryos, suggesting that Met is required for their formation. We used chemical inhibitors to test several downstream pathways activated by Met and found that secondary motoneuron development may depend on the p38 and/or Akt pathways. In contrast, primary motoneurons were present in met morpholino-injected embryos. However, a significant fraction of them had truncated axons. Surprisingly, some CaPs in met morpholino antisense oligonucleotide (MO)-injected embryos developed a hybrid morphology in which they had both a peripheral axon innervating muscle and an interneuron-like axon within the spinal cord. In addition, in met MO-injected embryos primary motoneurons co-expressed mRNA encoding Choline acetyltransferase, the synthetic enzyme for their normal neurotransmitter, acetylcholine, and mRNA encoding Glutamate decarboxylase 1, the synthetic enzyme for GABA, a neurotransmitter never normally found in these motoneurons, but found in several types of interneurons. Our inhibitor studies suggest that Met function in primary motoneurons may be mediated through the MEK1/2 pathway.

Conclusion

We provide evidence that Met is necessary for normal development of zebrafish primary and secondary motoneurons. Despite their many similarities, our results show that these two motoneuron subtypes have different requirements for Met function during development, and raise the possibility that Met may act through different intracellular signaling cascades in primary and secondary motoneurons. Surprisingly, although met is not expressed in primary motoneurons until many hours after they have extended axons to and innervated their muscle targets, Met knockdown causes some of these cells to develop a hybrid phenotype in which they co-expressed motoneuron and interneuron neurotransmitters and have both peripheral and central axons.
A 15N stable isotope semen label to detect mating in the malaria mosquito Anopheles arabiensis Patton
Authors: Helinski Michelle EH , Hood Rebecca C , Gludovacz Doris , Mayr Leo , Knols Bart GJ
Published: July 2008

In previous studies it was determined that the stable isotope 13-carbon can be used as a semen label to detect mating events in the malaria mosquito Anopheles arabiensis. In this paper we describe the use of an additional stable isotope, 15-nitrogen (15N), for that same purpose. Both stable isotopes can be analysed simultaneously in a mass spectrometer, offering the possibility to detect both labels in one sample in order to study complex and difficult-to-detect mating events, such as multiple mating. 15N-glycine was added to larval rearing water and the target enrichment was 5 atom% 15N. Males from these trays were mated with unlabelled virgin females, and spiked spermathecae were analysed for isotopic composition after mating using mass spectrometry. Results showed that spermathecae positive for semen could be distinguished from uninseminated or control samples using the raw δ15N‰ values. The label persisted in spermathecae for up to 5 days after insemination, and males aged 10 days transferred similar amounts of label as males aged 4 days. There were no negative effects of the label on larval survival and male longevity. Enrichment of teneral mosquitoes after emergence was 4.85 ± 0.10 atom% 15N. A threshold value defined as 3 standard deviations above the mean of virgin (i.e. uninseminated spermathecae) samples was successful in classifying a large proportion of samples correctly (i.e. on average 95%). We conclude that alongside 13C, 15N can be used to detect mating in Anopheles and the suitability of both labels is briefly discussed.
Cross-system effects of dysphagia treatment on dysphonia: a case report
Authors: LaGorio Lisa A , Carnaby-Mann Giselle D , Crary Michael A
Published: July 2008

Traditionally, treatment of dysphagia and dysphonia has followed a specificity approach whereby treatment plans have focused on each dysfunction individually. Recently however, a therapeutic cross-system effect has been proposed between these two dysfunctions. At least one study has demonstrated swallowing improvement in subjects who completed a dysphonia treatment program. However, we are unaware of any evidence demonstrating the converse effect. In this paper, we present a case-report of a 74 year old male who demonstrated improvement in selected vocal parameters after completion of a dysphagia therapy program.

Dysphagia therapy resulted in improved laryngeal function in this subject. Results implicate improved vocal fold tension with increased glottal closure. Further investigation into the potential for this cross-system effect is warranted.
A double blind, randomized, placebo controlled study of the efficacy and safety of 5-Loxin®for treatment of osteoarthritis of the knee
Authors: Sengupta Krishanu , Alluri Krishnaraju V , Satish Andey Rama , Mishra Simanchala , Golakoti Trimurtulu , Sarma Kadainti VS , Dey Dipak , Raychaudhuri Siba P
Published: July 2008

Introduction

5-Loxin® is a novel Boswellia serrata extract enriched with 30% 3-O-acetyl-11-keto-beta-boswellic acid (AKBA), which exhibits potential anti-inflammatory properties by inhibiting the 5-lipoxygenase enzyme. A 90-day, double-blind, randomized, placebo-controlled study was conducted to evaluate the efficacy and safety of 5-Loxin® in the treatment of osteoarthritis (OA) of the knee.

Methods

Seventy-five OA patients were included in the study. The patients received either 100 mg (n = 25) or 250 mg (n = 25) of 5-Loxin® daily or a placebo (n = 25) for 90 days. Each patient was evaluated for pain and physical functions by using the standard tools (visual analog scale, Lequesne's Functional Index, and Western Ontario and McMaster Universities Osteoarthritis Index) at the baseline (day 0), and at days 7, 30, 60 and 90. Additionally, the cartilage degrading enzyme matrix metalloproteinase-3 was also evaluated in synovial fluid from OA patients. Measurement of a battery of biochemical parameters in serum and haematological parameters, and urine analysis were performed to evaluate the safety of 5-Loxin® in OA patients.

Results

Seventy patients completed the study. At the end of the study, both doses of 5-Loxin® conferred clinically and statistically significant improvements in pain scores and physical function scores in OA patients. Interestingly, significant improvements in pain score and functional ability were recorded in the treatment group supplemented with 250 mg 5-Loxin® as early as 7 days after the start of treatment. Corroborating the improvements in pain scores in treatment groups, we also noted significant reduction in synovial fluid matrix metalloproteinase-3. In comparison with placebo, the safety parameters were almost unchanged in the treatment groups.

Conclusion

5-Loxin® reduces pain and improves physical functioning significantly in OA patients; and it is safe for human consumption. 5-Loxin® may exert its beneficial effects by controlling inflammatory responses through reducing proinflammatory modulators, and it may improve joint health by reducing the enzymatic degradation of cartilage in OA patients.

Trail Registration

(Clinical trial registration number: ISRCTN05212803.)
The role of glucocorticoids and progestins in inflammatory, autoimmune, and infectious disease
Authors: Tait A Sasha , Butts Cherie L , Sternberg Esther M
Published: July 2008

A bidirectional communication exists between the CNS and the immune system. The autonomic nervous system, through neurotransmitters and neuropeptides, works in parallel with the hypothalamic-pituitary-adrenal axis through the actions of glucocorticoids to modulate inflammatory events. The immune system, through the action of cytokines and other factors, in turn, activates the CNS to orchestrate negative-feedback mechanisms that keep the immune response in check. Disruption of these interactions has been associated with a number of syndromes including inflammatory, autoimmune, and cardiovascular diseases, metabolic and psychiatric disorders, and the development of shock. The hypothalamic-pituitary-gonadal axis also plays an important part in regulating immunity through the secretion of sex hormones. Although numerous studies have established a role for immunomodulation by estrogen and testosterone, the role of progesterone is less well understood. Progesterone is crucial for reproductive organ development and maintenance of pregnancy, and more recent studies have clearly shown its role as an important immune regulator. The main focus of this review will be about the role of steroid hormones, specifically glucocorticoids and progesterone, in inflammatory responses and infectious diseases and how dysregulation of their actions may contribute to development of autoimmune and inflammatory disease.
Exercise training-induced lowering of inflammatory (CD14+CD16+) monocytes: a role in the anti-inflammatory influence of exercise?
Authors: Timmerman Kyle L , Flynn Michael G , Coen Paul M , Markofski Melissa M , Pence Brandt D
Published: July 2008

Exercise training or higher levels of physical activity are known to exert anti-inflammatory effects. CD14+CD16+ monocytes are potent producers of inflammatory proteins, and elevated levels of these “inflammatory” monocytes have been implicated in disease development. Little is known about the influence of exercise training on this cell population. On the basis of their physical activity pattern, male and female subjects, 65–80 years old, were assigned to a physically active (PA; n=15) or inactive (PI; n=15) group. The PI group performed 12 weeks (3 days/week) of endurance (20 min at 70–80% heart-rate reserve) and resistance exercise training (eight exercises, two sets at 70–80% of one repetition maximum). Subjects in the PA group maintained their habitual activity level. Flow cytometry was used to determine monocyte phenotype and monocyte TLR4 expression. ELISAs were used to measure whole blood, LPS-stimulated TNF-α production, and serum C-reactive protein (CRP). At baseline, the PA group had a lower percentage of CD14+CD16+ monocytes and lower unstimulated production of TNF-α than the PI group. CD14+CD16+ monocyte percentage and 1 ng/ml LPS-stimulated TNF-α production were reduced after the PI group underwent 12 weeks of exercise training. PI subjects also had higher TLR4 expression on classical monocytes, but there were no significant exercise training-induced changes in monocyte TLR4 expression. The PA group had significantly lower serum CRP than the PI group. Physical activity was associated with lower CD14+CD16+ monocyte percentage and LPS-stimulated TNF-α production. Exercise training-induced reductions in CD14+CD16+ monocytes may contribute to the anti-inflammatory effects of exercise training.
Linear amplitude patterns in Corpus Christi Bay Frio Subbasin, south Texas: Interpretive pitfalls or depositional features?
Authors: Zeng Hongliu , Loucks Robert G. , Hammes Ursula
Published: July 2008

Linear amplitude patterns on stratal slices in the Corpus Christi Bay area of Texas are important seismic geomorphological features that reflect sediment dispersal patterns. These amplitude patterns are oriented in both strike and dip directions. Some of the linear amplitude patterns are related to faults; however, most are related to orientation of sandstone bodies. Faulting may make the depositionally related linear amplitude patterns more fragmented, but faults do not destroy the overall orientation or geomorphologic significance of these patterns. Amplitude patterns on stratal slices should be interpreted as unbiased, general, sediment-dispersal patterns unless the patterns can be tied directly to a structural feature. In-depth understanding of structural and depositionally related amplitude patterns leads to more accurate stratal slicing interpretation in facies/reservoir prediction using poststack 3D seismic data.
Combined Schlumberger and dipole-dipole array for hydrogeologic applications
Authors: Apostolopoulos G.
Published: July 2008

A novel approach to 2D resistivity sounding, called combined Schlumberger and dipole-dipole (CSDD) sounding, probes the subsurface both vertically and diagonally. It transforms the dipole-dipole values to Schlumberger values using the Patella method. Gridding then creates an apparent-resistivity section in which vertical variations are inferred from the Schlumberger values and lateral variations are inferred from the dipole-dipole values. The section is inverted by the Zohdy 1D method to vertical strips. The resulting 2D resistivity model of the subsurface identifies the layers and their dips. We tested the ability of the CSDD method to delineate a layered structure by comparing the method’s response to a model and then by a field test at a site where we have some degree of subsurface information from a resistivity tomography profile. Finally, we used this new CSDD sounding for hydrogeologic applications in the Agia Valley on Crete, Xylokastron City, and Skyros Island in Greece. The CSDD soundings map formations and interfaces at various depths and dips, including a phyllite-limestone interface and marl with overlying conglomerate. It also maps circulation, supply, and salinization of groundwater. In all cases, we find that CSDD sounding can detect the layers and their dips in sedimentary basins.
Electroseismic and seismoelectric measurements of rock samples in a water tank
Authors: Zhu Zhenya , Toksöz M. Nafi , Burns Daniel R.
Published: July 2008

An electromagnetic (EM) or seismic wave can induce seismic or EM waves because of the electrokinetic conversion based on the electric double layer in a fluid-saturated porous medium. We tested a new method for observing electroseismic and seismoelectric conversions in rock samples. Our method is designed to overcome the shortcoming of previous attempts to separate signals generated by a continuous electric or seismic source in a small container. We first observed acoustic fields around electrodes excited by an electric pulse in a water tank or in a water-saturated porous sample. In our approach, we immersed rock samples in a water tank and measure the seismic or electric responses using electric or acoustic pulses conveyed through the immersed electrodes or hydrophone. We measured electroseismic- and seismoelectric-frequency responses in Berea Sandstone and Westerly Granite samples at a frequency range of [Formula: see text]. The measurements clearly separate the effects of the electric source, background noises, and signals. We calculate the normalized electroseismic and seismoelectric coupling coefficients for rock samples and confirm our results by comparing them with those theoretically simulated in a closed-capillary model. The variation of normalized coupling coefficients in the frequency domain is similar to that in theoretical predictions. Our measurement method can be used to investigate electroseismic and seismoelectric properties for petroleum exploration applications.
Short Telomeres, Telomerase Reverse Transcriptase Gene Amplification, and Increased Telomerase Activity in the Blood of Familial Papillary Thyroid Cancer Patients
Authors: Capezzone Marco , Cantara Silvia , Marchisotta Stefania , Filetti Sebastiano , De Santi Maria Margherita , Rossi Benedetta , Ronga Giuseppe , Durante Cosimo , Pacini Furio
Published: July 2008

Background: Differentiated papillary thyroid cancer is mostly sporadic, but the recurrence of the familial form has been reported. Short or dysfunctional telomeres have been associated with familial benign diseases and familial breast cancer.

Objective: The aim of our work was to study the telomere-telomerase complex in the peripheral blood of patients with familial papillary thyroid cancer (FPTC), including the measurement of relative telomere length (RTL), telomerase reverse transcriptase (hTERT) gene amplification, hTERT mRNA expression, telomerase protein activity, and search of hTERT or telomerase RNA component gene mutations.

Patients: Cumulating a series of patients seen at the University of Siena and a series at the University of Rome, the experiments were conducted in 47 FPTC patients, 75 sporadic papillary thyroid cancer (PTC) patients, 20 patients with nodular goiter, 19 healthy subjects, and 20 unaffected siblings of FPTC patients.

Results: RTL, measured by quantitative PCR, was significantly (P < 0.0001) shorter in the blood of FPTC patients, compared with sporadic PTCs, healthy subjects, nodular goiter subjects, and unaffected siblings. Also by fluorescence in situ hybridization analysis, the results confirmed shorter telomere lengths in FPTC patients (P = 0.01). hTERT gene amplification was significantly (P < 0.0001) higher in FPTC patients, compared with the other groups, and in particular, it was significantly (P = 0.03) greater in offspring with respect to parents. hTERT mRNA expression, as well as telomerase activity, was significantly higher (P = 0.0003 and P < 0.0001, respectively) in FPTC patients, compared with sporadic PTCs. RTL, measured in cancer tissues, was shorter (P < 0.0001) in FPTC patients, compared with sporadic PTCs. No mutations of the telomerase RNA component and hTERT genes were found.

Conclusion: Our study demonstrates that patients with FPTC display an imbalance of the telomere-telomerase complex in the peripheral blood, characterized by short telomeres, hTERT gene amplification, and expression. These features may be implicated in the inherited predisposition to develop FPTC.
Increased Interleukin (IL)-1β Messenger Ribonucleic Acid Expression in β-Cells of Individuals with Type 2 Diabetes and Regulation of IL-1β in Human Islets by Glucose and Autostimulation
Authors: Böni-Schnetzler Marianne , Thorne Jeffrey , Parnaud Géraldine , Marselli Lorella , Ehses Jan A. , Kerr-Conte Julie , Pattou Francois , Halban Philippe A. , Weir Gordon C. , Donath Marc Y.
Published: July 2008

Context: Elevated glucose levels impair islet function and survival, and it has been proposed that intraislet expression of IL-1β contributes to glucotoxicity.

Objective: The objective was to investigate IL-1β mRNA expression in near-pure β-cells of patients with type 2 diabetes (T2DM) and study the regulation of IL-1β by glucose in isolated human islets.

Methods: Laser capture microdissection was performed to isolate β-cells from pancreas sections of 10 type 2 diabetic donors and nine controls, and IL-1β mRNA expression was analyzed using gene arrays and PCR. Cultured human islets and fluorescence-activated cell sorter-purified human β-cells were used to study the regulation of IL-1β expression by glucose and IL-1β.

Results: Gene array analysis of RNA from β-cells of individuals with T2DM revealed increased expression of IL-1β mRNA. Real-time PCR confirmed increased IL-1β expression in six of 10 T2DM samples, with minimal or no expression in nine control samples. In cultured human islets, IL-1β mRNA and protein expression was induced by high glucose and IL-1β autostimulation and decreased by the IL-1 receptor antagonist IL-1Ra. The glucose response was negatively correlated with basal IL-1β expression levels. Autostimulation was transient and nuclear factor-κB dependent. Glucose-induced IL-1β was biologically active and stimulated IL-8 release. Low picogram per milliliter concentrations of IL-1β up-regulated inflammatory factors IL-8 and IL-6.

Conclusion: Evidence that IL-1β mRNA expression is up-regulated in β-cells of patients with T2DM is presented, and glucose-promoted IL-1β autostimulation may be a possible contributor.
Rab18 and Rab43 have key roles in ER-Golgi trafficking
Authors: Dejgaard Selma Y. , Murshid Ayesha , Erman Ayşegül , Kızılay Özge , Verbich David , Lodge Robert , Dejgaard Kurt , Ly-Hartig Thi Bach Nga , Pepperkok Rainer , Simpson Jeremy C. , Presley John F.
Published: July 2008

Rabs and Arfs/Arls are Ras-related small GTPases of particular relevance to membrane trafficking. It is thought that these proteins regulate specific pathways through interactions with coat, motor, tether and SNARE proteins. We screened a comprehensive list of Arf/Arl/Rab proteins, previously identified on purified Golgi membranes by a proteomics approach (37 in total), for Golgi or intra-Golgi localization, dominant-negative and overexpression phenotypes. Further analysis of two of these proteins, Rab18 and Rab43, strongly indicated roles in ER-Golgi trafficking. Rab43-T32N redistributed Golgi elements to ER exit sites without blocking trafficking of the secretory marker VSVG-GFP from ER to cell surface. Wild-type Rab43 redistributes the p150Glued subunit of dynactin, consistent with a specific role in regulating association of pre-Golgi intermediates with microtubules. Overexpression of wild-type GFP-Rab18 or incubation with any of three siRNAs directed against Rab18 severely disrupts the Golgi complex and reduces secretion of VSVG. Rab18 mutants specifically enhance retrograde Golgi-ER transport of the COPI-independent cargo β-1,4-galactosyltransferase (Galtase)-YFP but not the COPI-dependent cargo p58-YFP from the Golgi to ER in a photobleach assay. Rab18-S22N also potentiated brefeldin-A-induced ER-Golgi fusion. This study is the first comprehensive application of large-scale proteomics to the cell biology of small GTPases of the secretory pathway.
The MAGUK-family protein CASK is targeted to nuclei of the basal epidermis and controls keratinocyte proliferation
Authors: Ojeh Nkemcho , Pekovic Vanja , Jahoda Colin , Määttä Arto
Published: July 2008

The Ca2+/calmodulin-associated Ser/Thr kinase (CASK) binds syndecans and other cell-surface proteins through its PDZ domain and has been implicated in synaptic assembly, epithelial polarity and neuronal gene transcription. We show here that CASK regulates proliferation and adhesion of epidermal keratinocytes. CASK is localised in nuclei of basal keratinocytes in newborn rodent skin and developing hair follicles. Induction of differentiation shifts CASK to the cell membrane, whereas in keratinocytes that have been re-stimulated after serum starvation CASK localisation shifts away from membranes upon entry to S phase. Biochemical fractionation demonstrates that CASK has several subnuclear targets and is found in both nucleoplasmic and nucleoskeletal pools. Knockdown of CASK by RNA interference leads to increased proliferation in cultured keratinocytes and in organotypic skin raft cultures. Accelerated cell cycling in CASK knockdown cells is associated with upregulation of Myc and hyperphosphorylation of Rb. Moreover, CASK-knockdown cells show increased hyperproliferative response to KGF and TGFα, and accelerated attachment and spreading to the collagenous matrix. These functions are reflected in wound healing, where CASK is downregulated in migrating and proliferating wound-edge keratinocytes.
P311 functions in an alternative pathway of lipid accumulation that is induced by retinoic acid
Authors: Leung James K. , Cases Sylvaine , Vu Thiennu H.
Published: July 2008

Lipid droplets are complex and dynamic intracellular organelles that have an essential role in cholesterol and lipid homeostasis, and profoundly affect cellular structure and function. Variations in lipid-droplet composition exist between different cell types, but whether there are differences in the mechanisms of lipid-droplet accumulation remains to be elucidated. Here, we report that P311, previously identified to have a function in neuronal regeneration and a potential role in distal lung generation, regulates lipid droplet accumulation. P311 upregulates several classes of genes associated with lipid synthesis, significantly increases intracellular cholesterol and triglyceride levels, and increases intracellular lipid droplets. Interestingly, P311 expression is not necessary for lipogenesis in the well-established NIH3T3-L1 cell model of adipogenic differentiation. Instead, we demonstrate a novel role for P311 in an alternative pathway of lipid-droplet accumulation that is induced by the regeneration-inducing molecule retinoic acid.
Distinct motifs in the chemokine receptor CCR7 regulate signal transduction, receptor trafficking and chemotaxis
Authors: Otero Carolina , Eisele Petra S. , Schaeuble Karin , Groettrup Marcus , Legler Daniel F.
Published: July 2008

The chemokine receptor CCR7, together with its ligands CCL19 and CCL21, is responsible for the correct homing and trafficking of dendritic cells and lymphocytes to secondary lymphoid tissues. Moreover, cancer cells can utilize CCR7 to metastasize to draining lymph nodes. However, information on CCR7 signaling leading to cell migration or receptor trafficking is sparse. Using novel CCR7 deletion mutants with successive truncations of the intracellular C-terminus and a mutant with impaired G-protein coupling, we identified distinct motifs responsible for various aspects of CCR7 signal transduction. Deleting a Ser/Thr motif at the tip of the intracellular tail of CCR7 resulted in an impaired chemokine-mediated activation of Erk1/2 kinases. Interestingly, deleting an additional adjacent motif restored the ability of CCL19-mediated Erk1/2 phosphorylation, suggesting the presence of a regulatory motif. Both the Ser/Thr and the regulatory motif are dispensable for signaling events leading to cell migration and receptor trafficking. A CCR7 mutant lacking virtually the complete C-terminus readily bound CCL19 and was internalized, but was unable to activate the G protein and to transmit signals required for cell migration, mobilization of [Ca2+]i and Erk1/2 activation. Finally, G-protein coupling was critical for [Ca2+]i mobilization, Erk1/2 phosphorylation and chemotaxis, but not for CCR7 trafficking.
Signalling by neurotrophins and hepatocyte growth factor regulates axon morphogenesis by differential β-catenin phosphorylation
Authors: David Monica D. , Yeramian Andrée , Duñach Mireia , Llovera Marta , Cantí Carles , de Herreros Antonio García , Comella Joan X. , Herreros Judit
Published: July 2008

Tyrosine phosphorylation of β-catenin, a component of adhesion complexes and of the Wnt pathway, affects cell adhesion, migration and gene transcription. By reducing β-catenin availability using shRNA-mediated gene silencing or expression of intracellular N-cadherin, we show that β-catenin is required for axon growth downstream of brain-derived neurotrophic factor (BDNF) signalling and hepatocyte growth factor (HGF) signalling. We demonstrate that the receptor tyrosine kinases (RTKs) Trk and Met interact with and phosphorylate β-catenin. Stimulation of Trk receptors by neurotrophins (NTs) results in phosphorylation of β-catenin at residue Y654, and increased axon growth and branching. Conversely, pharmacological inhibition of Trk or expression of a Y654F mutant blocks these effects. β-catenin phosphorylated at Y654 colocalizes with the cytoskeleton at growth cones. However, HGF, which also increases axon growth and branching, induces β-catenin phosphorylation at Y142 and a nuclear localization. Interestingly, dominant-negative ΔN-TCF4 abolishes the effects of HGF in axon growth and branching, but not that of NTs. We conclude that NT- and HGF-signalling differentially phosphorylate β-catenin, targeting this protein to distinct compartments to regulate axon morphogenesis by TCF4-transcription-dependent and -independent mechanisms. These results place β-catenin downstream of growth-factor–RTK signalling in axon differentiation.
Dynamics of component exchange at PML nuclear bodies
Authors: Weidtkamp-Peters Stefanie , Lenser Thorsten , Negorev Dmitri , Gerstner Norman , Hofmann Thomas G. , Schwanitz Georg , Hoischen Christian , Maul Gerd , Dittrich Peter , Hemmerich Peter
Published: July 2008

PML nuclear bodies (NBs) are involved in the regulation of key nuclear pathways but their biochemical function in nuclear metabolism is unknown. In this study PML NB assembly dynamics were assessed by live cell imaging and mathematic modeling of its major component parts. We show that all six nuclear PML isoforms exhibit individual exchange rates at NBs and identify PML V as a scaffold subunit. SP100 exchanges at least five times faster at NBs than PML proteins. Turnover dynamics of PML and SP100 at NBs is modulated by SUMOylation. Exchange is not temperature-dependent but depletion of cellular ATP levels induces protein immobilization at NBs. The PML-RARα oncogene exhibits a strong NB retention effect on wild-type PML proteins. HIPK2 requires an active kinase for PML NB targeting and elevated levels of PML IV increase its residence time. DAXX and BLM turn over rapidly and completely at PML NBs within seconds. These findings provide a kinetics model for factor exchange at PML NBs and highlight potential mechanisms to regulate intranuclear trafficking of specific factors at these domains.
An intact connexin N-terminus is required for function but not gap junction formation
Authors: Kyle John W. , Minogue Peter J. , Thomas Bettina C. , Domowicz Denise A. Lopez , Berthoud Viviana M. , Hanck Dorothy A. , Beyer Eric C.
Published: July 2008

The cytoplasmic N-termini of connexins have been implicated in protein trafficking, oligomerization and channel gating. To elucidate the role of the N-terminus in connexin37 (CX37), we studied mutant constructs containing partial deletions of its 23 N-terminal amino acids and a construct with a complete N-terminus in which residues 2-8 were replaced with alanines. All mutants containing nine or more N-terminal amino acids form gap junction plaques in transiently transfected HeLa cells, whereas most of the longer deletions do not. Although wild-type CX37 allowed intercellular transfer of microinjected neurobiotin in HeLa cells and formed conducting hemichannels in Xenopus oocytes, none of the mutant constructs tested show evidence of channel function. However, in coexpression experiments, N-terminal mutants that formed gap junction plaques potently inhibit hemichannel conductance of wild-type CX37 suggesting their co-oligomerization. We conclude that as much as half the length of the connexin N-terminus can be deleted without affecting formation of gap junction plaques, but an intact N-terminus is required for hemichannel gating and intercellular communication.
Postdischarge Oral Versus Injectable Anticoagulation Following Major Orthopedic Surgery
Authors: Shorr Andrew F , Nutescu Edith A , Farrelly Eileen , Horblyuk Ruslan , Happe Laura E , Franklin Meg
Published: July 2008

Background

Multiple clinical studies have shown postdischarge anticoagulation to bo beneficial following major orthopedic surgery (MOS); however, outpatient prophylaxis is not widely practiced.

Objective

To quantify, from a third-party payer perspective, real-world clinical and economic outcomes tor patients receiving injectable or oral anticoagulation as prophylaxis for venous thromboembolism (VTE) following discharge after MOS.

Methods

A retrospective database analysis was conducted using outpatient medical and pharmacy data from the PharMetrics Patient-Centric Database (January 1, 2002, to March 31, 2006). Patients greater than 18 years of age with 9 months of continuous eligibility who received an anticoagulant in the outpatient setting following MOS were eligible. Patients were stratified into 2 cohorts; injectable (dalteparin, enoxaparin, fondaparinux) and oral (warfarin), and were matched 1:1 on demographic and clinical characteristics.

Results:

A total of 12,724 patients were included (injectable, 6362; oral, 6362). At 90 days, patients receiving oral anticoagulation were 20% more likely to experience a VTE than were those receiving an injectable agent (7.4% vs 6.3%; p = 0.02, OR 1.18; 95% CI 1.03 to 1.36). No significant differences in bleeding were observed (<0.4%). The average adjusted total 6-month costs were significantly (p < 0.001) higher for the oral versus injectable cohort ($18,039 vs $16,429). Medical costs in the oral cohort offset the higher pharmacy costs in the injectable cohort.

Conclusions:

This study demonstrates that the risk of VTE extends to the outpatient setting following MOS, even with postdischarge anticoagulation. Injectable agents used in the outpatient setting may result in fewer clinical VTEs without increasing the risk for major bleeding. These findings support 1he data from controlled clinical studies and expand the evidence to the real-world setting. Despite higher pharmacy acquisition costs for injectable anticoagulants, injectable agents may offer significant per patient savings to third party payers.
Candesartan Cilexetil Effectively Reduces Blood Pressure in Hypertensive Children
Authors: Franks Amy M , O'Brien Catherine E , Stowe Cindy D , Wells Thomas G , Gardner Stephanie F
Published: July 2008

Background:

The angiotensin-receptor blocker candesartan cilexetil is a well-toleraled antihypertensive agent with demonstrated benefits in adults with hypertension. However, there are few data supporting its use in children with hypertension.

Objective:

To determine the efficacy and tolerability of candesartan cilexetil in the treatment of pediatric hypertension.

Methods:

In an open-label, uncontrolled pilot study, hypertensive pediatric patients were eligible tor participation if untreated systolic and/or diastolic blood pressure (BP) exceeded the 95th percentile for sex, age, and height. Patients underwent a 7-day washout period prior to initiation of weight-based dosing of candesartan cilexetil (2-8 mg daily). The dose was doubled after 7 days of therapy if inadequate antihypertensive response was determined by clinic-measured casual BP monitoring (CBPM) and home BP monitoring (HBPM). Three methods of BP measurement were compared before and after 2 weeks of treatment with the final dose of candesartan cilexetil: CBPM, HBPM, and 24-hour continuous ambulatory BP monitoring (ABPM). Self-reported adverse effects and clinical laboratory analyses were used to determine tolerability.

Results:

Eleven patients (mean age 14.2 y) received a final candesartan cilexetil median daily dose of 8 mg (0.13 mg/kg, range 2-16 mg). Study treatment resulted in significant reductions in systolic and diastolic BP as measured by CBPM (-7.4%, p = 0,03 and -5.9%, p = 0.01, respectively) and by ABPM (-6.0%, p = 0.03 and -10.8%, p = 0.006, respectively), but no significant reductions as measured by HBPM. No clinically significant changes in laboratory measures were observed, and patients reported nonspecific mild adverse effects.

Conclusions:

Candesartan cilexetil effectively reduced BP as demonstrated by CBPM and ABPM measurements and was well tolerated in this group of hypertensive children.
The Interface between Extracellular and Transmembrane Domains of Homomeric Cys-Loop Receptors Governs Open-Channel Lifetime and Rate of Desensitization
Authors: Bouzat Cecilia , Bartos Mariana , Corradi Jeremías , Sine Steven M.
Published: July 2008

The lifetimes of activated postsynaptic receptor channels contribute to the efficiency of synaptic transmission. Here we show that structural differences within the interface dividing extracellular and transmembrane domains of homomeric α7 and 5-HT3Areceptors account for the large differences in open-channel lifetime and time of desensitization onset between these contrasting members of the Cys-loop receptor superfamily. For α7 receptors, agonist-evoked single-channel currents appear mainly as isolated brief openings (τo= 0.35 ms), whereas macroscopic currents after a step pulse of agonist desensitize rapidly (τd= 0.4 ms). In contrast for 5-HT3Areceptors, agonist-evoked single-channel currents appear as clusters of many long openings in quick succession (τcluster= 1.2 s), whereas macroscopic currents desensitize slowly (τd= 1.1 s). A chimeric α7-5HT3Areceptor exhibits functional properties intermediate between those of the parent receptors, but the functional signatures of each parent are reconstituted after substituting the major loops within the interface of the extracellular and transmembrane domains from the corresponding parent receptor. Furthermore, these structural loops contribute to open-channel lifetime and time of desensitization onset in a nonadditive manner. The results suggest that desensitization is the major determinant of the lifetimes of activated α7 and 5-HT3Areceptors and that functional differences between the two receptors arise primarily through structural differences at the interface between extracellular and transmembrane domains.
Zebrafish Olfactomedin 1 Regulates Retinal Axon ElongationIn Vivoand Is a Modulator of Wnt Signaling Pathway
Authors: Nakaya Naoki , Lee Hee-Sheung , Takada Yuichiro , Tzchori Itai , Tomarev Stanislav I.
Published: July 2008

Olfactomedin 1 (Olfm1) is a secreted glycoprotein belonging to a family of olfactomedin domain-containing proteins. It is involved in the regulation of neural crest production in chicken and promotes neuronal differentiation inXenopus. Here, we investigate the functions of Olfm1 in zebrafish eye development. Overexpression of full-length Olfm1, and especially its BMY form lacking the olfactomedin domain, increased the thickness of the optic nerve and produced a more extended projection field in the optic tectum compared with control embryos. In contrast, injection ofolfm1–morpholino oligonucleotide (Olfm1–MO) reduced the eye size, inhibited optic nerve extension, and increased the number of apoptotic cells in the retinal ganglion cell and inner nuclear layers. Overexpression of full-length Olfm1 increased the lateral separation of the expression domains of eye-field markers,rx3andsix3. The Olfm1–MO had the opposite effect. These data suggest that zebrafish Olfm1 may play roles in the early eye determination, differentiation, optic nerve extension, and branching of the retinal ganglion cell axon terminals, with the N-terminal region of Olfm1 being critical for these effects. Injection of RNA encoding WIF-1, a secreted inhibitor of Wnt signaling, caused changes in the expression pattern ofrx3similar to those observed after Olfm1–MO injection. Simultaneous overexpression of WIF-1 and Olfm1 abolished the WIF-1 effect. Physical interaction of WIF-1 and Olfm1 was demonstrated by coimmunoprecipitation experiments. We concluded that Olfm1 serves as a modulator of Wnt signaling.
Sequence Reactivation in the Hippocampus Is Impaired in Aged Rats
Authors: Gerrard Jason L. , Burke Sara N. , McNaughton Bruce L. , Barnes Carol A.
Published: July 2008

The hippocampus is thought to coordinate memory consolidation by reactivating traces from behavioral experience when the brain is not actively processing new input. In fact, during slow-wave sleep, the patterns of CA1 pyramidal cell ensemble activity correlations are reactivated in both young and aged rats. In addition to correlated activity patterns, repetitive track running also creates a recurring sequence of pyramidal cell activity. The present study compared CA1 sequence activity pattern replay in young and old animals during rest periods after behavior. Whereas the young rats exhibited significant sequence reactivation, it was markedly impaired in the aged animals. When the spatial memory scores of all animals were compared with the degree of sequence reactivation, there was a significant correlation. The novel finding that weak replay of temporal patterns has behavioral consequences, strengthens the idea that reactivation processes are integral to memory consolidation.
Analog Modulation of Mossy Fiber Transmission Is Uncoupled from Changes in Presynaptic Ca2+
Authors: Scott Ricardo , Ruiz Arnaud , Henneberger Christian , Kullmann Dimitri M. , Rusakov Dmitri A.
Published: July 2008

Subthreshold somatic depolarization has been shown recently to modulate presynaptic neurotransmitter release in cortical neurons. To understand the mechanisms underlying this mode of signaling in the axons of dentate granule cells (hippocampal mossy fibers), we have combined two-photon Ca2+imaging with dual-patch recordings from somata and giant boutons forming synapses on CA3 pyramidal cells. In intact axons, subthreshold depolarization propagates both orthodromically and antidromically, with an estimated length constant of 200–600 μm depending on the signal waveform. Surprisingly, presynaptic depolarization sufficient to enhance glutamate release at mossy fiber–CA3 pyramidal cell synapses has no detectable effect on either basal Ca2+-dependent fluorescence or action-potential-evoked fluorescence transients in giant boutons. We further estimate that neurotransmitter release varies with presynaptic Ca2+entry with a 2.5-power relationship and that depolarization-induced synaptic facilitation remains intact in the presence of high-affinity presynaptic Ca2+buffers or after blockade of local Ca2+stores. We conclude that depolarization-dependent modulation of transmission at these boutons does not rely on changes in presynaptic Ca2+.
Complementary Contributions of Prefrontal Neuron Classes in Abstract Numerical Categorization
Authors: Diester Ilka , Nieder Andreas
Published: July 2008

The primate prefrontal cortex (PFC) plays a cardinal role in forming abstract categories and concepts. However, it remains elusive how this is accomplished and to what extent the interaction of functionally distinct neuron classes underlies this representation. Here, we inferred the major cortical cell types, putative pyramidal cells, and interneurons by characterizing the waveforms of action potentials recorded in monkeys performing a cognitively demanding numerosity categorization task. Putative interneurons responded much faster than cells classified as pyramidal neurons and exhibited a higher reliability of category discrimination, whereas putative pyramidal cells showed a higher degree of category selectivity. An analysis of the numerosity tuning profiles and the temporal interactions of adjacent neurons indicated that inhibitory input by putative interneurons shapes the tuning to numerical categories of putative PFC pyramidal cells. These findings favor feedforward mechanisms subserving cognitive categorization and help to clarify cellular interactions in PFC microcircuits.
Activation of the β-Adrenoceptor–Protein Kinase A Signaling Pathway within the Ventral Bed Nucleus of the Stria Terminalis Mediates the Negative Affective Component of Pain in Rats
Authors: Deyama Satoshi , Katayama Takahiro , Ohno Atsushi , Nakagawa Takayuki , Kaneko Shuji , Yamaguchi Taku , Yoshioka Mitsuhiro , Minami Masabumi
Published: July 2008

Pain is an unpleasant sensory and emotional experience. The neural systems underlying the sensory component of pain have been studied extensively, but we are only beginning to understand those underlying its affective component. The bed nucleus of the stria terminalis (BNST) has been implicated in stress responses and negative affective states, such as anxiety, fear, and aversion. Recently, we demonstrated the crucial role of the BNST in the negative affective component of pain using the conditioned place aversion (CPA) test. In the present study, we investigated the involvement of the β-adrenoceptor–protein kinase A (PKA) signaling pathway within the BNST, in particular, within the ventral part of the BNST (vBNST), in pain-induced aversion in male Sprague Dawley rats.In vivomicrodialysis showed that extracellular noradrenaline levels within the vBNST were significantly increased by intraplantar formalin injection. Using the CPA test, we found that intra-vBNST injection of timolol, a β-adrenoceptor antagonist, dose-dependently attenuated the intraplantar-formalin-induced CPA (F-CPA) without reducing nociceptive behaviors. Experiments with subtype-selective antagonists demonstrated the essential role of β2-adrenoceptors in F-CPA. Intra-vBNST injection of isoproterenol, a β-adrenoceptor agonist, dose-dependently produced CPA even in the absence of noxious stimulation. This isoproterenol-induced CPA was reversed by the coinjection of Rp-cyclic adenosine monophosphorothioate (Rp-cAMPS), a selective PKA inhibitor. Furthermore, intra-vBNST injection of Rp-cAMPS dose-dependently attenuated the F-CPA. Together, these results suggest that PKA activation within the vBNST via the enhancement of β-adrenergic transmission is important for the negative affective component of pain.
Ras Signaling Mechanisms Underlying Impaired GluR1-Dependent Plasticity Associated with Fragile X Syndrome
Authors: Hu Hailan , Qin Yi , Bochorishvili Genrieta , Zhu Yinghua , van Aelst Linda , Zhu J. Julius
Published: July 2008

Fragile X syndrome, caused by the loss ofFMR1gene function and loss of fragile X mental retardation protein (FMRP), is the most commonly inherited form of mental retardation. The syndrome is characterized by associative learning deficits, reduced risk of cancer, dendritic spine dysmorphogenesis, and facial dysmorphism. However, the molecular mechanism that links loss of function ofFMR1to the learning disability remains unclear. Here, we report an examination of small GTPase Ras signaling and synaptic AMPA receptor (AMPA-R) trafficking in cultured slices and intact brains of wild-type andFMR1knock-out mice. InFMR1knock-out mice, synaptic delivery of GluR1-, but not GluR2L- and GluR4-containing AMPA-Rs is impaired, resulting in a selective loss of GluR1-dependent long-term synaptic potentiation (LTP). Although Ras activity is upregulated, its downstream MEK (extracellular signal-regulated kinase kinase)–ERK (extracellular signal-regulated kinase) signaling appears normal, and phosphoinositide 3-kinase (PI3K)–protein kinase B (PKB; or Akt) signaling is compromised inFMR1knock-out mice. Enhancing Ras–PI3K–PKB signaling restores synaptic delivery of GluR1-containing AMPA-Rs and normal LTP inFMR1knock-out mice. These results suggest aberrant Ras signaling as a novel mechanism for fragile X syndrome and indicate manipulating Ras–PI3K–PKB signaling to be a potentially effective approach for treating patients with fragile X syndrome.
Amphetamine Activation of Hippocampal Drive of Mesolimbic Dopamine Neurons: A Mechanism of Behavioral Sensitization
Authors: Lodge Daniel J. , Grace Anthony A.
Published: July 2008

The repeated administration of psychostimulants induces an enhanced behavioral response to a subsequent drug challenge. This behavioral sensitization is proposed to model the increased drug craving observed in human psychostimulant abusers. Usingin vivoextracellular recordings from identified ventral tegmental area dopamine (DA) neurons, we report that amphetamine-sensitized rats display an activation of ventral hippocampal neuron firing and a significantly greater number of spontaneously active DA neurons compared with saline-treated rats. Moreover, TTX inactivation of the ventral hippocampus restores DA neuron activity to control levels and also blocks the expression of locomotor sensitization. Taken as a whole, we propose that behavioral sensitization to psychostimulant drugs is attributable, at least in part, to persistent activation of the ventral hippocampus–nucleus accumbens pathway, with the resultant increase in tonic DA neuron firing enabling an abnormally higher response to subsequent psychostimulant administration.