bluuebunny/crossref_metadata_2025 huggingface dataset:
ON THE INFERENCE OF PARSIMONIOUS INDEL EVOLUTIONARY SCENARIOS
Authors: CHINDELEVITCH LEONID , LI ZHENTAO , BLAIS ERIC , BLANCHETTE MATHIEU
Published: September 2006

Given a multiple alignment of orthologous DNA sequences and a phylogenetic tree for these sequences, we investigate the problem of reconstructing a most parsimonious scenario of insertions and deletions capable of explaining the gaps observed in the alignment. This problem, called the Indel Parsimony Problem, is a crucial component of the problem of ancestral genome reconstruction, and its solution provides valuable information to many genome functional annotation approaches. We first show that the problem is NP-complete. Second, we provide an algorithm, based on the fractional relaxation of an integer linear programming formulation. The algorithm is fast in practice, and the solutions it produces are, in most cases, provably optimal. We describe a divide-and-conquer approach that makes it possible to solve very large instances on a simple desktop machine, while retaining guaranteed optimality. Our algorithms are tested and shown efficient and accurate on a set of 1.8 Mb mammalian orthologous sequences in the CFTR region.
Chemokine Antagonists as Therapeutics: Focus on HIV-1
Authors: Tsibris Athe M.N. , Kuritzkes Daniel R.
Published: September 2006

Human immunodeficiency virus type 1 (HIV-1) entry into target cells is a multistep process involving the interaction of viral envelope proteins with cell surface receptors. Binding to CD4 is followed by engagement of specific chemokine receptors (CCR5 or CXCR4), triggering molecular rearrangements in the envelope transmembrane subunit that result in membrane fusion. Chemokine receptor antagonists that block the interaction of the HIV-1 envelope with CCR5 or CXCR4 potently inhibit HIV-1 in vitro. Pilot studies of orally bioavailable small-molecule CCR5 inhibitors in HIV-1-infected subjects have provided proof of concept for this novel drug class; phase III safety and efficacy trials are under way.
Exogenous sphingosine 1-phosphate and sphingosine kinase activated by endothelin-1 induced myometrial contraction through differential mechanisms
Authors: Leiber Denis , Banno Yoshiko , Tanfin Zahra
Published: September 2006

Sphingosine 1-phosphate (S1P), a bioactive sphingolipid involved in diverse biological processes, is generated by sphingosine kinase (SphK) and acts via intracellular and/or extracellular mechanisms. We used biochemical, pharmacological, and physiological approaches to investigate in rat myometrium the contractile effect of exogenous S1P and the possible contribution of SphK in endothelin-1 (ET-1)-mediated contraction. S1P stimulated uterine contractility (EC50= 1 μM and maximal response = 5 μM) by a pertussis toxin-insensitive and a phospholipse C (PLC)-independent pathway. Phosphorylated FTY720, which interacts with all S1P receptors, except S1P2receptors, failed to mimic S1P contractile response, indicating that the effects of S1P involved S1P2receptors that are expressed in myometrium. Contraction mediated by S1P and ET-1 required extracellular calcium and Rho kinase activation. Inhibition of SphK reduced ET-1-mediated contraction. ET-1, via ETAreceptors coupled to pertussis toxin-insensitive G proteins, stimulated SphK1 activity and induced its translocation to the membranes. Myometrial contraction triggered by ET-1 is consecutive to the sequential activation of PLC, protein kinase C, SphK1 and Rho kinase. Prolonged exposure of the myometrium to S1P downregulated S1P2receptors and abolished the contraction induced by exogenous S1P. However, in these conditions, the tension triggered by ET-1 was not reduced, indicating that SphK activated by ET-1 contributed to its contractile effect via a S1P2receptor-independent process. Our findings demonstrated that exogenous S1P and SphK activity regulated myometrial contraction and may be of physiological relevance in the regulation of uterine motility during gestation and parturition.
SCAM analysis reveals a discrete region of the pore turret that modulates slow inactivation in Kv1.5
Authors: Eduljee Cyrus , Claydon Thomas W. , Viswanathan Vijay , Fedida David , Kehl Steven J.
Published: September 2006

In Kv1.5, protonation of histidine 463 in the S5-P linker (turret) increases the rate of depolarization-induced inactivation and decreases the peak current amplitude. In this study, we examined how amino acid substitutions that altered the physico-chemical properties of the side chain at position 463 affected slow inactivation and then used the substituted cysteine accessibility method (SCAM) to probe the turret region (E456-P468) to determine whether residue 463 was unique in its ability to modulate the macroscopic current. Substitutions at position 463 of small, neutral (H463G and H463A) or large, charged (H463R, H463K, and H463E) side groups accelerated inactivation and induced a dependency of the current amplitude on the external potassium concentration. When cysteine substitutions were made in the distal turret (T462C-P468C), modification with either the positively charged [2-(trimethylammonium)ethyl] methanethiosulfonate bromide (MTSET) or negatively charged sodium (2-sulfonatoethyl) methanethiosulfonate reagent irreversibly inhibited current. This inhibition could be antagonized either by the R487V mutation (homologous to T449V in Shaker) or by raising the external potassium concentration, suggesting that current inhibition by MTS reagents resulted from an enhancement of inactivation. These results imply that protonation of residue 463 does not modulate inactivation solely by an electrostatic interaction with residues near the pore mouth, as proposed by others, and that residue 463 is part of a group of residues within the Kv1.5 turret that can modulate P/C-type inactivation.
Multiple repressor pathways contribute to phenotypic switching of vascular smooth muscle cells
Authors: Kawai-Kowase Keiko , Owens Gary K.
Published: September 2006

Smooth muscle cell (SMC) differentiation is an essential component of vascular development and these cells perform biosynthetic, proliferative, and contractile roles in the vessel wall. SMCs are not terminally differentiated and possess the ability to modulate their phenotype in response to changing local environmental cues. The focus of this review is to provide an overview of the current state of knowledge of molecular mechanisms involved in controlling phenotypic switching of SMC with particular focus on examination of processes that contribute to the repression of SMC marker genes. We discuss the environmental cues which actively regulate SMC phenotypic switching, such as platelet-derived growth factor-BB, as well as several important regulatory mechanisms required for suppressing expression of SMC-specific/selective marker genes in vivo, including those dependent on conserved G/C-repressive elements, and/or highly conserved degenerate CArG elements found in the promoters of many of these marker genes. Finally, we present evidence indicating that SMC phenotypic switching involves multiple active repressor pathways, including Krüppel-like zinc finger type 4, HERP, and ERK-dependent phosphorylation of Elk-1 that act in a complementary fashion.
Increased expression of midkine in the rat colon during healing of experimental colitis
Authors: Yuki Takafumi , Ishihara Shunji , Rumi M. A. K. , Ortega-Cava Cesar F. , Kadowaki Yasunori , Kazumori Hideaki , Ishimura Norihisa , Amano Yuji , Moriyama Nobuyuki , Kinoshita Yoshikazu
Published: September 2006

Midkine (MK) is a unique growth and differentiation factor that modulates the proliferation and migration of various cells; however, little is known regarding its relationship to intestinal diseases. The aim of this study was to investigate MK expression and its role in dextran sulfate sodium (DSS)-induced colitis in rats. The expressions of MK, receptor-like protein-tyrosine phosphatase (RPTP)-β, and proinflammatory cytokines were examined in rat colonic tissues after the development of DSS-induced colitis using Northern blotting, immunohistochemistry, and laser-capture microdissection (LCM) coupled with RT-PCR. The effects of MK on the migration of intestinal epithelial cells (IEC-6) were also evaluated in vitro using an intestinal wound repair model. MK expression was significantly increased in damaged colonic mucosa, mainly from day 3 to day 5 after the end of DSS administration, with abundant MK immunoreactive signals detected in submucosal fibroblasts. Expressions of proinflammatory cytokines were most strongly induced on day 1, which preceded the augmentation of MK expression. Results of LCM coupled with RT-PCR clearly indicated RPTP-β expression in colonic epithelial cells. The migration assay showed that wound repair in the MK-treated groups was accelerated dose dependently. The present results showed for the first time that intestinal inflammation upregulates the MK-RPTP-β system, which may stimulate mucosal regeneration during the process of healing of colitis. Additional investigations regarding the role of MK may contribute to the development of new options for the treatment of inflammatory bowel diseases.
Vigilance state-dependent attenuation of hypercapnic chemoreflex and exaggerated sleep apnea in orexin knockout mice
Authors: Nakamura Akira , Zhang Wei , Yanagisawa Masashi , Fukuda Yasuichiro , Kuwaki Tomoyuki
Published: September 2006

Exogenous administration of orexin can promote wakefulness and respiration. Here we examined whether intrinsic orexin participates in the control of breathing in a vigilance state-dependent manner. Ventilation was recorded together with electroencephalography and electromyography for 6 h during the daytime in prepro-orexin knockout mice (ORX-KO) and wild-type (WT) littermates. Respiratory parameters were separately determined during quiet wakefulness (QW), slow-wave sleep (SWS), or rapid eye movement (REM) sleep. Basal ventilation was normal in ORX-KO, irrespective of vigilance states. The hypercapnic ventilatory response during QW in ORX-KO (0.19 ± 0.01 ml·min−1·g−1·%CO2−1) was significantly smaller than that in WT mice (0.38 ± 0.04 ml·min−1·g−1·%CO2−1), whereas the responses during SWS and REM in ORX-KO were comparable to those in WT mice. Hypoxic responses during wake and sleep periods were not different between the genotypes. Spontaneous but not postsigh sleep apneas were more frequent in ORX-KO than in WT littermates during both SWS and REM sleep. Our findings suggest that orexin plays a crucial role both in CO2 sensitivity during wakefulness and in preserving ventilation stability during sleep.
Stimulus-Dependent Alterations in Quantal Neurotransmitter Release
Authors: Grabner Chad P. , Fox Aaron P.
Published: September 2006

Neurotransmitter release is a steep function of the intracellular calcium ion concentration ([Ca2+]i) at the release sites. Both the Ca2+amplitude and the time course appear to be important for specifying neurotransmitter release. Ca2+influx regulates the number of vesicles exocytosed as well as the amount of neurotransmitter each individual vesicle releases. In our study we stimulated mouse chromaffin cells in two different ways to alter Ca2+presentation at the release sites. One method, digitonin permeabilization followed by exposure to Ca2+, allows for a large uniform global elevation of [Ca2+]i, whereas the second method, application of nicotine, depolarizes chromaffin cells and activates voltage-dependent Ca2+channels, thereby producing more phasic and localized changes in [Ca2+]i. Using amperometry to monitor catecholamine release, we show that both kinds of stimuli elicit the exocytosis of similar quantities of neurotransmitter per large dense core vesicles (LDCVs) released. Even so, the release process was quite different for each stimulus; nicotine-elicited events were small and slow, whereas digitonin events were, in comparison, large and fast. In addition, the transient opening of the fusion pore, called the “foot,” was essentially absent in digitonin-stimulated cells, but was quite common in nicotine-stimulated cells. Thus even though both strong stimuli used in this study elicited the release of many vesicles it appears that the differences in the Ca2+levels at the release sites were key determinants for the fusion and release of individual vesicles.
Load Signals Assist the Generation of Movement-Dependent Reflex Reversal in the Femur–Tibia Joint of Stick Insects
Authors: Akay Turgay , Büschges Ansgar
Published: September 2006

Reinforcement of movement is an important mechanism by which sensory feedback contributes to motor control for walking. We investigate how sensory signals from movement and load sensors interact in controlling the motor output of the stick insect femur–tibia (FT) joint. In stick insects, flexion signals from the femoral chordotonal organ (fCO) at the FT joint and load signals from the femoral campaniform sensilla (fCS) are known to individually reinforce stance-phase motor output of the FT joint by promoting flexor and inhibiting extensor motoneuron activity. We quantitatively compared the time course of inactivation in extensor tibiae motoneurons in response to selective stimulation of fCS and fCO. Stimulation of either sensor generates extensor activity in a qualitatively similar manner but with a significantly different time course and frequency of occurrence. Inactivation of extensor motoneurons arising from fCS stimulation was more reliable but more than threefold slower compared with the extensor inactivation in response to flexion signals from the fCO. In contrast, simultaneous stimulation of both sense organs produced inactivation in motoneurons with a time course typical for fCO stimulation alone, but with a frequency of occurrence characteristic for fCS stimulation. This increase in probability of occurrence was also accompanied by a delayed reactivation of the extensor motoneurons. Our results indicate for the first time that load signals from the leg affect the processing of movement-related feedback in controlling motor output.
Activity-Dependent Modulation of Axonal Excitability in Unmyelinated Peripheral Rat Nerve Fibers by the 5-HT(3) Serotonin Receptor
Authors: Lang Philip M. , Moalem-Taylor Gila , Tracey David J. , Bostock Hugh , Grafe Peter
Published: September 2006

Activity-dependent fluctuations in axonal excitability and changes in interspike intervals modify the conduction of trains of action potentials in unmyelinated peripheral nerve fibers. During inflammation of a nerve trunk, long stretches of axons are exposed to inflammatory mediators such as 5-hydroxytryptamine [5-HT]. In the present study, we have tested the effects of m-chlorophenylbiguanide (mCPBG), an agonist at the 5-HT(3) serotonin receptor, on activity- and potential-dependent variations in membrane threshold and conduction velocity of unmyelinated C-fiber axons of isolated rat sural nerve segments. The increase in axonal excitability during application of mCPBG was much stronger at higher frequencies of action potentials and/or during axonal membrane hyperpolarization. The effects on the postspike recovery cycle also depended on the rate of stimulation. At an action potential frequency of 1 Hz or in hyperpolarized axons, mCPBG produced a loss of superexcitability. In contrast, at 0.33 Hz, a small increase in the postspike subexcitability was observed. Similar effects on excitability changes were found when latency instead of threshold was recorded, but only at higher action potential frequencies: at 1.8 Hz, mCPBG increased conduction velocity and reduced postspike supernormality. The latter effect would increase the interspike interval if pairs of action potentials were conducted along several cm in an inflamed nerve trunk. These data indicate that activation of axonal 5-HT(3) receptors not only enhances membrane excitability but also modulates action potential trains in unmyelinated, including nociceptive, nerve fibers at high impulse rates.
The Morbidity Associated with Osteochondral Harvest from Asymptomatic Knees for the Treatment of Osteochondral Lesions of the Talus
Authors: Reddy Sudheer , Pedowitz David I. , Parekh Selene G. , Sennett Brian J. , Okereke Enyi
Published: September 2006

Background

Mosaic autogenous osteochondral transplantation has been used to treat large osteochondral defects.

Hypothesis

There is potential, previously unrecognized donor-site morbidity associated with osteochondral harvest from asymptomatic knees for the treatment of talar osteochondral defect lesions.

Study Design

Case series; Level of evidence, 4.

Methods

Fifteen patients underwent mosaic osteochondral transplantation to treat a talar osteochondral defect lesion, with 11 patients available for follow-up. A Lysholm knee score was used to assess donor-site morbidity at a mean follow-up of 47 months (range, 7-77 months). Mean age was 29 years (range, 21-44 years). A single surgical team performed the mosaicplasties. Significance was determined using the Student t test.

Results

All patients had asymptomatic knees preoperatively. Mean postoperative Lysholm score was 81 (range, 49-100). By Lysholm criteria, 5 rated as excellent, 2 as good, and 4 as poor. No significant difference was detected in terms of the harvest method or the number of grafts obtained from those having an excellent rating versus those having a good/poor rating. Patients rated as good/poor cited knee instability in daily activities as the most common problem. One had knee pain and patellar instability after osteochondral harvest by lateral arthrotomy that required a subsequent lateral retinacular release and tibial tubercle osteotomy.

Conclusion

This study demonstrates that donor-site morbidity after osteochondral harvest can be significant. In this population, those who experienced a decline in knee function had problems performing activities of daily living. When performing these procedures, the authors recommend that surgeons consider these risks and discuss them with their patients.
Hydrogel Meniscal Replacement in the Sheep Knee
Authors: Kelly Bryan T. , Robertson William , Potter Hollis G. , Deng Xiang-Hua , Turner A. Simon , Lyman Stephen , Warren Russell F. , Rodeo Scott A.
Published: September 2006

Background

Meniscal allograft transplantation has become a viable surgical alternative for a select group of patients with deficient or irreparable menisci. Subjective results are encouraging; long-term success, durability, and safety of allograft meniscal transplantation are uncertain.

Purposes

To evaluate a novel hydrogel meniscal replacement implant in an ovine model and assess chondroprotective effects of this hydrogel meniscal replacement using several validated outcome measures.

Study Design

Controlled laboratory study.

Methods

Fourteen skeletally mature sheep underwent hydrogel meniscal replacement; 45 additional animals had previously undergone 1 of 3 operations: lateral meniscectomy (24), meniscal allograft transplant (17), and sham (4). Animals were sacrificed at 2, 4, or 12 months. Cartilage was assessed by magnetic resonance imaging, gross inspection, biomechanical testing, and semiquantitative histological analysis.

Results

There were no differences between the sham operation and nonoperated control limbs. Compared with meniscectomy, hydrogel meniscal replacement resulted in significantly decreased cartilage degeneration with all outcome parameters (P < .05). Compared with nonoperated control limbs, hydrogel meniscal replacements demonstrated no significant differences at 2 months in any category. By 4 months, hydrogel limbs demonstrated significantly greater cartilage degeneration than did nonoperated control limbs in all categories. Compared with meniscal allograft transplantation animals, hydrogel meniscal replacements demonstrated no differences at 2 months but had significantly increased cartilage degeneration in the peripheral zone of the tibial plateau at 4 months (P < .05). At 1 year, all hydrogel implants had developed complete radial splits in the posterior third of the implant.

Conclusion

Although promising preliminary results for hydrogel meniscal replacement were seen at early time points, significant cartilage degeneration and implant failure were seen at 1 year, and overall performance was worse than was allograft transplantation. Improvements in hydrogel material properties and surface characteristics and more accurate size matching may improve outcomes.

Clinical Relevance

Improvements in the hydrogel material properties and surface characteristics and more accurate size matching may lead to the use of hydrogel implants in humans.
Over-expression of AhR (aryl hydrocarbon receptor) induces neural differentiation of Neuro2a cells: neurotoxicology study
Authors: Akahoshi Eiichi , Yoshimura Seiko , Ishihara-Sugano Mitsuko
Published: September 2006

Background

Dioxins and related compounds are suspected of causing neurological disruption in human and experimental animal offspring following perinatal exposure during development and growth. The molecular mechanism(s) of the actions in the brain, however, have not been fully investigated. A major participant in the process of the dioxin-toxicity is the dioxin receptor, namely the aryl hydrocarbon receptor (AhR). AhR regulates the transcription of diverse genes through binding to the xenobiotic-responsive element (XRE). Since the AhR has also been detected in various regions of the brain, the AhR may play a key role in the developmental neurotoxicity of dioxins. This study focused on the effect of AhR activation in the developing neuron.

Methods

The influence of the AhR on the developing neuron was assessed using the Neuro2a-AhR transfectant. The undifferentiated murine neuroblastoma Neuro2a cell line (ATCC) was stably transfected with AhR cDNA and the established cell line was named N2a-Rα. The activation of exogenous AhR in N2a-Rα cells was confirmed using RNAi, with si-AhR suppressing the expression of exogenous AhR. The neurological properties of N2a-Rα based on AhR activation were evaluated by immunohistochemical analysis of cytoskeletal molecules and by RT-PCR analysis of mRNA expression of neurotransmitter-production related molecules, such as tyrosine hydroxylase (TH).

Results

N2a-Rα cells exhibited constant activation of the exogenous AhR. CYP1A1, a typical XRE-regulated gene, mRNA was induced without the application of ligand to the culture medium. N2a-Rα cells exhibited two significant functional features. Morphologically, N2a-Rα cells bore spontaneous neurites exhibiting axon-like properties with the localization of NF-H. In addition, cdc42 expression was increased in comparison to the control cell line. The other is the catecholaminergic neuron-like property. N2a-Rα cells expressed tyrosine hydroxylase (TH) mRNA as a functional marker of catecholaminergic neurotransmitter production. Thus, exogenous AhR induced catecholaminergic differentiation in N2a-Rα cells.

Conclusion

The excessive activation of AhR resulted in neural differentiation of Neuro2a cells. This result revealed that dioxins may affect the nervous system through the AhR-signaling pathway. Activated AhR may disrupt the strictly regulated brain formation with irregular differentiation occurring rather than cell death.
Long-term cyclical in vivoloading increases cartilage proteoglycan content in a spatially specific manner: an infrared microspectroscopic imaging and polarized light microscopy study
Authors: Saadat Ehsan , Lan Howard , Majumdar Sharmila , Rempel David M , King Karen B
Published: September 2006

Understanding the changes in collagen and proteoglycan content of cartilage due to physical forces is necessary for progress in treating joint disorders, including those due to overuse. Physical forces in the chondrocyte environment can affect the cellular processes involved in the biosynthesis of extracellular matrix. In turn, the biomechanical properties of cartilage depend on its collagen and proteoglycan content. To understand changes due to physical forces, this study examined the effect of 80 cumulative hours of in vivo cyclical joint loading on the cartilage content of proteoglycan and collagen in the rabbit metacarpophalangeal joint. The forepaw digits of six anesthetized New Zealand White adult female rabbits were repetitively flexed at 1 Hz with an estimated joint contact pressure of 1 to 2 MPa. Joints were collected from loaded and contralateral control specimens, fixed, decalcified, embedded, and thin-sectioned. Sections were examined under polarized light microscopy to identify and measure superficial and mid zone thicknesses of cartilage. Fourier Transform Infrared microspectroscopy was used to measure proteoglycan and collagen contents in the superficial, mid, and deep zones. Loading led to an increase in proteoglycan in the cartilage of all six rabbits. Specifically, there was a 46% increase in the cartilage deep zone (p = 0.003). The collagen content did not change with loading. Joint loading did not change the superficial and mid zone mean thicknesses. We conclude that long-term (80 cumulative hours) cyclical in vivo joint loading stimulates proteoglycan synthesis. Furthermore, stimulation is localized to cartilage regions of high hydrostatic pressure. These data may be useful in developing interventions to prevent overuse injuries or in developing therapies to improve joint function.
Novel IL10 gene family associations with systemic juvenile idiopathic arthritis
Authors: Fife Mark S , Gutierrez Ana , Ogilvie Emma M , Stock Carmel JW , Samuel Jane M , Thomson Wendy , Mack Lisa F , Lewis Cathryn M , Woo Patricia
Published: September 2006

Juvenile idiopathic arthritis (JIA) is the most common cause of chronic childhood disability and encompasses a number of disease subgroups. In this study we have focused on systemic JIA (sJIA), which accounts for approximately 11% of UK JIA cases. This study reports the investigation of three members of the IL10 gene family as candidate susceptibility loci in children with sJIA. DNA from 473 unaffected controls and 172 patients with sJIA was genotyped for a single nucleotide polymorphism (SNP) in IL19 and IL20 and two SNPs in IL10. We examined evidence for association of the four SNPs by single marker and haplotype analysis. Significant differences in allele frequency were observed between cases and controls, for both IL10-1082 (p = 0.031) and IL20-468 (p = 0.028). Furthermore, examination of the haplotypes of IL10-1082 and IL20-468 revealed greater evidence for association (global p = 0.0006). This study demonstrates a significant increased prevalence of the low expressing IL10-1082 genotype in patients with sJIA. In addition, we show a separate association with an IL20 polymorphism, and the IL10-1082A/IL20-468T haplotype. The two marker 'A-T' haplotype confers an odds ratio of 2.24 for sJIA. This positive association suggests an important role for these cytokines in sJIA pathogenesis.
Syntaxin 1A promotes the endocytic sorting of EAAC1 leading to inhibition of glutamate transport
Authors: Yu Yong-Xin , Shen Li , Xia Peng , Tang Ya-Wei , Bao Lan , Pei Gang
Published: September 2006

The neuronal glutamate transporter, excitatory amino-acid carrier 1 (EAAC1), plays an important role in the modulation of neurotransmission and contributes to synthesis of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and to epileptogenesis. However, the mechanisms that regulate EAAC1 endocytic sorting and function remain largely unknown. Here, we first demonstrate that EAAC1 undergoes internalization through the clathrin-mediated pathway and further show that syntaxin 1A, a key molecule in synaptic exocytosis, potentiates EAAC1 internalization, thus leading to the functional inhibition of EAAC1. In the presence of the transmembrane domain of syntaxin 1A, its H3 coiled-coil domain of syntaxin 1A is necessary and sufficient for the inhibition of EAAC1. Furthermore, specific suppression of endogenous syntaxin 1A significantly blocked EAAC1 endocytic sorting and lysosomal degradation promoted by kainic acid, a drug for kindling the animal model of human temporal lobe epilepsy in rat, indicating a potential role of syntaxin 1A in epileptogenesis. These findings provide new evidence that syntaxin 1A serves as an intrinsic enhancer to EAAC1 endocytic sorting and further suggest that syntaxin 1A is conversant with both `ins' and `outs' of synaptic neurotransmission.
The abundance of the spliceosomal snRNPs is not limiting the splicing of U12-type introns
Authors: Pessa Heli K.J. , Ruokolainen Annukka , Frilander Mikko J.
Published: September 2006

The rate of excision of U12-type introns has been reported to be slower than that of U2-type introns, suggesting a rate-limiting bottleneck that could down-regulate genes containing U12-type introns. The mechanistic reasons for this slower rate of intron excision are not known, but lower abundance of the U12-type snRNPs and slower rate of assembly or catalytic activity have been suggested. To investigate snRNP abundance we concentrated on the U4atac snRNA, which is the least abundant of the U12-type snRNAs and is limiting the formation of U4atac/U6atac complex. We identified mouse NIH-3T3 cell line isolates in which the level of both U4atac snRNA and U4atac/U6atac complexes is reduced to 10%–20% of the normal level. We used these cell lines to investigate splicing efficiency by transient transfection of a reporter gene containing a U12-type intron and by quantitative PCR analysis of endogenous genes. The splicing of the reporter U12-type intron was very inefficient, but the activity could be restored by overexpression of U4atac snRNA. Using these U4atac-deficient NIH-3T3 cells, we confirmed the results of previous studies showing that U12-type introns of endogenous genes are, indeed, excised more slowly than U2-type introns, but we found that the rate did not differ from that measured in cells displaying normal levels of U4atac snRNA. Thus our results suggest that the cellular abundance of the snRNPs does not limit U12-type intron splicing under normal conditions.
Epidemiology of laryngeal cancer
Authors: Krajina Z. , KulC'AR Z. , Konić‐Carnelutti V.
Published: September 2006

The patients with cancer of the larynx at the Ear, Nose and Throat Department in Zagreb during the period from 1945 to 1972, and the cases of laryngeal cancer at the Institute of Public Health of Croatia, were examined epidemiologically. The patients were from all parts of Croatia (west and south part of Yugoslavia) with the characteristics of Mediterranean and Continental climate.

The following factors were discussed: age and sex distribution, localization of the tumor in three compartments of the larynx, relationship between the villages and cities, occupation (peasants, workers and intellectual people), histologic types and the etiological factors (smoking and alcohol).
Panel on epidemiology and etiology of laryngeal carcinoma
Authors: Hiranandani L. H.
Published: September 2006

Ours is a developing country. We have still not controlled the common infectious diseases which are extinct in the West; therefore, our limited resources are spent on study of epidemiology of infectious diseases.

My conclusions on epidemiology of cancer of the larynx are drawn from observations made of the clinical material over a period of 25 years.

I have come to the conclusion that the smoked tobacco and the slaked lime in the Indian “Pan” are the two important carcinogenic agents.

Poor nutrition appears to be carcinogenic. It requires study and confirmation at a cellular level. Misuse of voice does seem to be the cause of laryngeal cancer.

Racial, genetic and other environmental factors, including pollution have not contributed to the increased incidence of laryngeal cancers.

The common histological types of laryngeal cancer are known. My observations on certain biological behavior of the tumor have been helpful.

1. An exophytic growth is less infiltrative; its metastatic mass reflects the same characteristics.

2. Certain anaplastic tumors can flout all laws of cancer spread and metastasize in distal organs.

3. Presence of reticular hyperplasia in peripheral lymph nodes is of good prognostic value.
Analysis of Protein Expression in Cell Microarrays: A Tool for Antibody-based Proteomics
Authors: Andersson Ann-Catrin , Strömberg Sara , Bäckvall Helena , Kampf Caroline , Uhlen Mathias , Wester Kenneth , Pontén Fredrik
Published: September 2006

Tissue microarray (TMA) technology provides a possibility to explore protein expression patterns in a multitude of normal and disease tissues in a high-throughput setting. Although TMAs have been used for analysis of tissue samples, robust methods for studying in vitro cultured cell lines and cell aspirates in a TMA format have been lacking. We have adopted a technique to homogeneously distribute cells in an agarose gel matrix, creating an artificial tissue. This enables simultaneous profiling of protein expression in suspension- and adherent-grown cell samples assembled in a microarray. In addition, the present study provides an optimized strategy for the basic laboratory steps to efficiently produce TMAs. Presented modifications resulted in an improved quality of specimens and a higher section yield compared with standard TMA production protocols. Sections from the generated cell TMAs were tested for immunohistochemical staining properties using 20 well-characterized antibodies. Comparison of immunoreactivity in cultured dispersed cells and corresponding cells in tissue samples showed congruent results for all tested antibodies. We conclude that a modified TMA technique, including cell samples, provides a valuable tool for high-throughput analysis of protein expression, and that this technique can be used for global approaches to explore the human proteome.
In Vivo Functional Analysis of Polyglutamic Acid Domains in Recombinant Bone Sialoprotein
Authors: Wazen Rima M. , Tye Coralee E. , Goldberg Harvey A. , Hunter Graeme K. , Smith Charles E. , Nanci Antonio
Published: September 2006

Bone sialoprotein (BSP) is an anionic phosphoprotein expressed in mineralizing connective tissues that binds to hydroxyapatite and nucleates its formation in vitro. Two polyglutamic acid regions (poly [E]) are believed to participate in these activities. The aim of this study was to evaluate the contribution of these acidic regions to the binding of prokaryote recombinant BSP (prBSPE) within an actual in vivo environment. Full-length prBSPE and prBSPE in which the poly [E] domains were replaced by polyalanine (prBSPA) were tagged with dinitrophenol (DNP). Tagged preparations comprised intact molecules and some fragmented forms. They were infused through a surgically created hole in the bone of rat hemimandibles and detected using immunogold labeling with anti-DNP antibodies. prBSPE-DNP was consistently immunodetected along exposed mineralized bone surfaces and osteocyte canaliculi at the surgical site. Few gold particles were observed on these surfaces when prBSPA-DNP was infused. Quantitative analyses showed significant differences in labeling between prBSPE-DNP (5.04 ± 0.73 particles/μm2) and prBSPA-DNP (1.37 ± 0.35 particles/μm2). These results indicate that poly [E] domains influence binding of prBSPE to surfaces presenting a mixture of mineral and proteins bathed by tissue fluids and suggest that they may similarly mediate the interaction of native BSP in the bone environment.
Fluorescence Visualization of Branchial Collagen Columns Embraced by Pillar Cells
Authors: Kudo Hisayuki , Kato Akira , Hirose Shigehisa
Published: September 2006

A collagen column is a structure of the extracellular matrix that helps to maintain the flatness and width of gill lamella. Collagen columns are unique in that they are enfolded by plasma membrane of pillar cells that form two-dimensional vascular networks between parallel sheets of respiratory epithelia. Despite their unique structure and fundamental importance in the physiology of aquatic animals, little is known about their properties and molecular components, owing to the lack of detection methods. In this study we demonstrated that collagen columns can be visualized by staining with fluorescencelabeled concanavalin A (ConA), a lectin that specifically recognizes the trimannoside core of N-glycosylated proteins and histidine-tagged green fluorescent protein (His6-Xpress-GFP), a fluorescent substrate for transglutaminase. We constructed a three-dimensional image of a pillar cell and visualized the spatial relationship between collagen columns and contractile apparatuses within the pillar cell body. This manuscript contains online supplemental material at http://www.jhc.org . Please visit this article online to view these materials.
Adaptive Behaviour and Moral Reasoning in Children with Frontal Lobe Lesions
Authors: Couper Emma , Jacobs Rani , Anderson Vicki
Published: September 2006

Children with frontal lobe damage often appear to demonstrate remarkable recovery with few apparent signs of impairment immediately after injury. Over time, however, many develop increasing deficits in self-regulation, attention, and executive function, as well as in otherhigher functions. Current literature suggests that, in particular, these children seem to experience worsening socio-behavioural problems. Some case studies (Grattan & Eslinger, 1992; Anderson et al., 1999) describe individuals with childhood frontal lesions who developed severe social problems, deficits in executive functions and who also had lower than expected levels of moral reasoning. In the present study, social-adaptive behaviour and maturity of moral reasoning were measured in 16 children with focal frontal lesions and in 12 age-matched controls. Children with frontal lobe lesions had poorer adaptive behaviour ratings and lower levels of moral maturity than controls. These results support previous research suggesting that children with frontal lobe lesions have reduced social understanding and typically experience ongoing sociobehavioural problems.
Memory for Faces and Paired Associates After Temporal Lobectomy in Childhood
Authors: Rothwell Andrew G. , Tucker Alan
Published: September 2006

Findings are reported from the first examination of the Beardsworth Memory for Children's Faces Test (BMCFT) (Beardsworth & Zaidel, 1994) tested on a selected sample of 10 left (LATL) and 7 right (RATL) anterior temporal lobectomy patients an average of 7 years post surgery. No differences between LATL and RATL groups were found on immediate or delayed memory trials of the BMCFT. Verbal memory was assessed with a verbal analogue of this test, the Extended Verbal Paired Associates Test (EVPAT) specifically constructed for this study. Differences were obtained on the immediate (F = 5.17; p < .01) and delayed (F = 6.55; p < .01) memory trials of the EVPAT with LATL patients learning and retrieving fewer verbal associations than their right ATL counterparts. No differences were found on the memory decline to delayed recall scores on the EVPAT. The findings suggest that people who have left or right ATL in childhood cannot be distinguished on the basis of their immediate or delayed memory for paired faces an average of 7 years post-surgery. These results are consistent with the immediate memory performance of children 6 months post-surgery as reported by Beardsworth and Zaidel (1994), but are not consonant with the delayed memory performance of their children on this task. This indicates that left-right dissociations found in children on measures of delayed memory for faces 6 months post-surgery may represent a component of memory that is still in a state of recovery. The findings for the immediate memory trials of the EVPAT conformed to expectations and underscore the dependability of simple rote verbal memory tasks in dissociating left from right ATL 7 years post-surgery. The study addresses the issue of the recovery of immediate versus delayed memory and time of assessment post-surgery.
An Analysis of the 2005 Japanese General Election: Will Koizumi's Political Reforms Endure?
Authors: Christensen Ray
Published: September 2006

Japan's Prime Minister Koizumi Junichiro has attempted to reform both Japan's economy and the ruling Liberal Democratic Party. Despite his party's landslide victory in the 2005 election, Koizumi's political reforms are unlikely to have a lasting impact on either party or electoral politics.
Tensions in South Korean Political Parties in Transition: From Entourage to Ideology?
Authors: Steinberg David I. , Shin Myung
Published: September 2006

South Korea's political parties, previously characterized as vehicles by leaders to recruit entourages to win presidential elections, are becoming more ideologically oriented. The ruling party's new left-wing elites and a new labor party are central to these tensions between entourage and ideology. Growing ideological orientation may affect both political development and the ROK-U.S. alliance.
The Authoritarian Temptation in East Timor: Nationbuilding and the Need for Inclusive Governance
Authors: Simonsen Sven Gunnar
Published: September 2006

Three political arenas in East Timor are examined regarding the goal of consolidating peace: governance under Fretilin leadership, the issue of official languages, and the security sector. The article finds that inclusiveness, transparency, and efforts to minimize conflict are lacking in current policies and political processes.
Japan's Shift Toward a Westminster System: A Structural Analysis of the 2005 Lower House Election and Its Aftermath
Authors: Estévez-Abe Margarita
Published: September 2006

This article argues that the political drama surrounding Prime Minister Koizumi Junichiro is a direct result of the political reforms implemented in Japan during the last decade. The new rules of the game have produced a structural force pushing Japan to resemble a Westminster system.
Effects of Predation by Nonnative Smallmouth Bass on Native Salmonid Prey: The Role of Predator and Prey Size
Authors: Fritts Anthony L. , Pearsons Todd N.
Published: September 2006

The size of predators that consume the most fish and the size of prey fish that are the most vulnerable to predation are important factors to consider when assessing the predation risks to valued prey fish such as Chinook salmonOncorhynchus tshawytschain the Pacific Northwest. We found that native salmonids' risk of predation by nonnative smallmouth bassMicropterus dolomieuin the lower Yakima River, Washington, generally decreased with increasing predator and prey size. Among smallmouth bass, those with fork lengths (FLs) ranging from 150 to 199 mm consumed 42.9% of the salmonids consumed. Overall, most of the salmonids were consumed by smallmouth bass smaller than 250 mm (69.6%), and the vast majority were consumed by smallmouth bass smaller than 300 mm (83.6%). Small smallmouth bass were much more abundant than large smallmouth bass, and the proportion of smallmouth bass that contained salmonid prey items in the gut decreased with increasing predator size. Salmonids that were 100 mm or larger were rarely consumed by smallmouth bass. We found that the maximum relative length of salmonids ([prey length/predator length] × 100) consumed by smallmouth bass was 56.6%. In addition, the relative length of salmonid prey decreased with increasing smallmouth bass size. Smallmouth bass generally ate salmonids at lengths that were less than 50% of predator capacity and that averaged 25% of predator length. The introduction of smallmouth bass to the Yakima River appears to have changed the size‐based predation risk dynamics in the lower river, which were historically dominated by northern pikeminnowPtychocheilus oregonensis.
Small‐Scale Genetic Structure and Variation in Steelhead of the Grande Ronde River, Oregon, USA
Authors: Narum Shawn R. , Boe Steve , Moran Paul , Powell Matt
Published: September 2006

Patterns of genetic variation in summer‐run steelhead Oncorhynchus mykiss from the Grande Ronde River, Oregon, were evaluated with 20 microsatellite loci to determine the level of fine‐scale genetic structure and influences from hatchery‐reared stocks. Included were temporal collections of three wild populations (Lookingglass Creek, Catherine Creek, and the upper Grande Ronde River) and one hatchery population (Wallowa Hatchery). Average gene diversity was moderate to high in all collections (range = 0.794–0.815). Genetic variance among sample locations was greater than that of temporal collections within sites, as pairwise exact tests within populations were not significant except for Lookingglass Creek (P = 0.00005). Structure among the four populations was evident from pairwise tests, which yielded 23 significant results from 28 comparisons (adjusted critical value = 0.0018), but Catherine Creek collections were not significantly different from Wallowa Hatchery collections. None of the eight collections had a significant probability of differing from mutation drift equilibrium (e.g., recent bottleneck) under the two‐phased mutation model (P = 0.060–0.985) when analyzed with BOTTLENECK software. Additionally, the ratios of allele number to allele range (M values) for the eight collections (0.773–0.819) were not within the range that suggests a recent decrease in effective population size (M < 0.68 implies a probable bottleneck). Results from this study suggest the existence of gene flow between steelhead from Catherine Creek and Wallowa Hatchery, but no evidence for low diversity or recent bottleneck events was detected in any of the four populations. This study provides several pieces of evidence to suggest that steelhead in the Grande Ronde River should be a conservation priority as a source of genetic diversity for the Snake River basin.
Migratory Behavior of American Shad in the York River, Virginia, with Implications for Estimating In‐River Exploitation from Tag Recovery Data
Authors: Olney John E. , Latour Robert J. , Watkins Brian E. , Clarke Douglas G.
Published: September 2006

Tagging of American shad Alosa sapidissima may alter their migratory behavior, causing some tagged individuals to cease or delay the spawning run. In a tag recovery study designed to assess fishery impacts, this altered behavior would reduce the number of tagged fish available to the target fishery and would bias estimates of exploitation and fishing mortality rates. To investigate this possibility, we fitted 29 prespawning adults with acoustic tags and released the fish into the middle reaches of the York River, Virginia. Movements of individuals were remotely monitored at three hydrophone stations: (1) 7 river kilometers (rkm) downriver of the release site; (2) on the Mattaponi River, 48 rkm upriver of the release location; and (3) on the Pamunkey River, 56 rkm upriver of the release location. Almost half of the fish were apparently affected by capture, handling, and tagging, as they either abandoned their migration or delayed their upstream movements. The movements of some fish appeared to be unaffected by capture; these fish were not detected at the downriver station and were detected on the spawning grounds 2–5 d after release. Eighteen fish remained on the spawning grounds for 17–51 d (average = 34.4 d) and were last detected at the downriver location, presumably during their seaward migration. Of the 26 tagged fish that migrated to either tributary after release, 15 originally selected spawning grounds on the Mattaponi River and 11 selected the Pamunkey River. One fish occupied both tributaries for several weeks each, suggesting possible spawning at both locations. We conclude that tagging protocols designed to measure the impacts of fishing on American shad should include telemetry to assess altered migratory behavior.