bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiating lexical form, meaning, and structure in the neural language system
Authors: Tyler L. K. , Marslen-Wilson W. D. , Stamatakis E. A.
Published: May 2005

A technique for studying the relationship between brain and language, which involves correlating scores on two continuous variables, signal intensity across the entire brains of brain-damaged patients and behavioral priming scores, was used to investigate a central issue in cognitive neuroscience: Are the components of the neural language system organized as a single undifferentiated process, or do they respond differentially to different types of linguistic structure? Differences in lexical structure, in the form of the regular and irregular past tense, have proven to be critical in this debate by contrasting a highly predictable rule-like process (e.g., jump-jumped) with an unpredictable idiosyncratic process typified by the irregulars (e.g., think-thought). The key issue raised by these contrasts is whether processing regular and irregular past tense forms differentially engages different aspects of the neural language system or whether they are processed within a single system that distinguishes between them purely on the basis of phonological and semantic differences. The correlational analyses provide clear evidence for a functional differentiation between different brain regions associated with the processing of lexical form, meaning, and morphological structure.
Regulation of anxiety and initiation of sexual behavior by CREB in the nucleus accumbens
Authors: Barrot Michel , Wallace Deanna L. , Bolaños Carlos A. , Graham Danielle L. , Perrotti Linda I. , Neve Rachael L. , Chambliss Heather , Yin Jerry C. , Nestler Eric J.
Published: May 2005

Sexual deficits and other behavioral disturbances such as anxiety-like behaviors can be observed in animals that have undergone social isolation, especially in species having important social interactions. Using a model of protracted social isolation in adult rats, we observed increased anxiety-like behavior and deficits in both the latency to initiate sexual behavior and the latency to ejaculate. We show, using transgenic cAMP response element (CRE)-LacZ reporter mice, that protracted social isolation also reduces CRE-dependent transcription within the nucleus accumbens. This decrease in CRE-dependent transcription can be mimicked in nonisolated animals by local viral gene transfer of a dominant negative mutant of CRE-binding protein (CREB). We previously showed that this manipulation increases anxiety-like behavior. We show here that it also impairs initiation of sexual behavior in nonisolated animals, a deficit that can be corrected by anxiolytic drug treatment. This local reduction in CREB activity, however, has no influence on ejaculation parameters. Reciprocally, we used the viral transgenic approach to overexpress CREB in the nucleus accumbens of isolated animals. We show that this local increase in CREB activity completely rescued the anxiety phenotype of the isolated animals, as well as their deficit in initiating sexual behavior, but failed to rescue the deficit in ejaculation. Our data suggest a role for the nucleus accumbens in anxiety responses and in specific aspects of sexual behavior. The results also provide insight into the molecular mechanisms by which social interactions affect brain plasticity and behavior.
Focal colors are universal after all
Authors: Regier Terry , Kay Paul , Cook Richard S.
Published: May 2005

It is widely held that named color categories in the world's languages are organized around universal focal colors and that these focal colors tend to be chosen as the best examples of color terms across languages. However, this notion has been supported primarily by data from languages of industrialized societies. In contrast, recent research on a language from a nonindustrialized society has called this idea into question. We examine color-naming data from languages of 110 nonindustrialized societies and show that (i) best-example choices for color terms in these languages cluster near the prototypes for Englishwhite,black,red,green,yellow, andblue, and (ii) best-example choices cluster more tightly across languages than do the centers of category extensions, suggesting that universal best examples (foci) may be the source of universal tendencies in color naming.
The effect of dietary copper on the fatty acid composition and physical properties of pig adipose tissues
Authors: Moore J.H. , Christle W.W. , Braude R. , Mitchell K. G
Published: May 2005

1. Control groups of pigs were given a basal diet alone and treated groups received the same diet supplemented with 250 ppm of copper. The animals were about 10 weeks of age at the start of the experiments and were killed when they weighed 90 kg live weight.

2. The ratio of oleic acid to stearic acid in the whole back fat (inner plus outer layers) was somewhat higher in the pigs given the copper supplement than in the control animals. The melting point of the back fat was about 10° lower in the pigs given the copper supplement than in the control groups.

3. Separate analyses of the inner and outer layers of the back fat showed that the ratio of oleic acid to stearic acid in the outer fat layer of the control pigs, and in both the inner and the outer fat layers of the pigs given the copper supplement, was somewhat higher than that in the inner fat layer of the control animals. The melting point of the outer fat layer of the control pigs and of both back fat layers in the pigs given the copper supplement was 10–15° lower than that of the inner fat layer of the control groups.

4. Evidence is presented that changes in the positional distribution of the fatty acids within the triglycerides of the back fats rather than differences in gross fatty acid composition are mainly responsible for the observed differences in physical properties.
The effect of vitamin D in rats maintained on diets with different mineral content but with the same calcium to phosphorus ratio of unity
Authors: Harrand R. B. , Hartles R. L.
Published: May 2005

1. Eight groups of ten weanling rats were maintained for 60 d on diets containing calcium and phosphorus in the ratio 1:1 (w/w) at four different levels of mineral, namely 0.08, 0.12, 0.24 and 0.36% Ca, with and without the addition of ergocalciferol.

2. Provision of vitamin D increased final body-weight except at the highest level of mineral intake. Similarly, increasing the mineral intake increased final body-weight except at the highest level.

3. Vitamin D raised the serum Ca concentration at all levels of mineral intake but in the experiment as a whole had no significant effect on serum P concentration. Serum Ca concentration was significantly higher at the two higher levels of mineral intake than at the two lower levels. Increasing dietary mineral caused a progressive increase in serum P concentration, except at the highest level of intake.

4. In general, the addition of vitamin D to the diets had no effect on the fresh or dry weights of the humeri; there was an indication, however, that at the two lower levels of mineral intake, vitamin D reduced the fresh weight of bone. The addition of the vitamin caused a reduction in bone volume, and an increase in bone length, bone ash and the ratio of the weight of ash to the weight of organic matter in dry, fat-free bone. With increasing dietary mineral there was an increase in the value of all the bone measurements except bone volume, which was decreased.

5. The addition of vitamin D and increasing dietary mineral both caused an increase in tooth mass and ash content.

6. The ratios of tooth mass to bone mass, and tooth ash to bone ash were unaffected by vitamin D, but decreased with increasing mineral intake.

7. Histological examination of the bones showed that the animals receiving 0.08 % of Ca and P were markedly rachitic although the presence of vitamin D ameliorated the condition. When the dietary mineral intake was raised to 0.12% Ca and P the animals were less severely rachitic and in the presence of vitamin D the bones appeared normal.

8. The incisor teeth were abnormal at the two lower levels of mineral intake, but when vitamin D was provided, the histological appearance was improved. When the Ca and P level in the diet was 0.24%, the incisal dentine appeared normal but the apical predentine was slightlywider thannormal; addition of vitamin D produced teeth of normal appearance. The incisor teeth were normal in appearance in the remaining groups.

9. These results are compared with those obtained in two previous studies where the Ca to P ratios were 1:10 and 10:1 (Harrand & Hartles, 1968, 1969).
The urinary aromatic acids excreted by sheep given S24 perennial ryegrass cut at six stages of maturity
Authors: Martin A. K.
Published: May 2005

1. S 24 perennial ryegrass was harvested at six stages of its growth from young leafy herbage to mature grass in which the seed had shed.

2. Two sheep were offered 1kg/d of each cut and two other sheep were offered 750 g/d of each cut of grass.

3. The contents of some possible precursors of the urinary aromatic acids excreted by sheep, namely, shikimic acid, quinic acid, chlorogenic acid, total o-dihydroxyphenolic compounds, lignin and crude protein were determined in each cut of grass.

4. A gas-liquid chromatographic method for the determination of the aromatic acids present in light petroleum extracts of urine was developed.

5. The urinary excretion of creatinine, diethyl ether-soluble acids, hippuric acid, total benzoic, phenylacetic and phenylpropionic acids, and the apparent digestibilities of nitrogen, lignin and dry matter were determined with each sheep offered each cut of grass.

6. The quantity of the various aromatic acid fractions excreted by sheep decreased as the maturity of the herbage increased and was directly proportional to the amount of food consumed.

7. No relationship was found between the intake of possible benzoic acid precursors and the urinary excretion of benzoic acid. With diets of young herbage, smaller amounts of benzoic acid were excreted in the urine than would be predicted from the intakes of the precursors studied, and with mature herbage greater amounts were excreted than would be predicted.

8. Possible reasons for these results are discussed, and the nature of additional precursors of urinary aromatic acids excreted by sheep given mature herbages are considered.

9. Urinary excretion of phenylacetic acid varied with diet in a manner which closely followed the intake of apparently digestible nitrogen. A highly significant (P < 0.001) exponential relationship was found between these two variables; it was log10E = 0.05 N –0.63, where E is the urinary phenylacetic acid output (g/kg food) and N the intake of apparently digestible nitrogen (g/kg food).
Effects of zinc deficiency on food intake and feeding patterns of rats
Authors: Chesters J. K. , Quarterman J.
Published: May 2005

1. The effects of alterations of the protein and zinc concentrations of a semi-synthetic diet on the food intake and dietary preferences of Zn-deficient and normal rats have beencompared.

2. The voluntary food intake of Zn-deficient rats fell to 70% 96 of that of the controls. The day-to-day variation of intake increased markedly and was associated with a cyclical pattern of food consumption. When the food intake of deficient rats was slightly restricted the troughs of the cycles disappeared.

3. Concurrent with the fall in food intake, Zn-deficient rats ceased to gain weight, but a similar change was found with pair-fed controls.

4. Force-feeding Zn-deficient rats with 140 % of their voluntary intake rapidly induced signs of ill-health.

5. Reduction of the protein content of the diet from 20 to 5 % resulted in an increased food intake and the disappearance of the cyclical pattern of intake. Growth, however, was not renewed.

6. Zn-deficient rats responded to a Zn-supplemented diet within 1–2 h by an increased food intake.

7. Zn-deficient rats were able to discriminate between diets containing 6 and I ppm Zn when both diets were offered simultaneously.

8. The responses of Zn-deficient rats to Zn-containing diets did not occur if the diets did not contain protein.
Cloning and Functional Characterization of a Formin-Like Protein (AtFH8) from Arabidopsis
Authors: Yi Kexi , Guo Chunqing , Chen Ding , Zhao Binbin , Yang Bin , Ren Haiyun
Published: May 2005

The actin cytoskeleton is required for many cellular processes in plant cells. The nucleation process is the rate-limiting step for actin assembly. Formins belong to a new class of conserved actin nucleator, which includes at least 2 formin homology domains, FH1 and FH2, which direct the assembly of unbranched actin filaments. The function of plant formins is quite poorly understood. Here, we provide the first biochemical study of the function of conserved domains of a formin-like protein (AtFH8) from Arabidopsis (Arabidopsis thaliana). The purified recombinant AtFH8(FH1FH2) domain has the ability to nucleate actin filaments in vitro at the barbed end and caps the barbed end of actin filaments, decreasing the rate of subunit addition and dissociation. In addition, purified AtFH8(FH1FH2) binds actin filaments and severs them into short fragments. The proline-rich domain (FH1) of the AtFH8 binds directly to profilin and is necessary for nucleation when actin monomers are profilin bound. However, profilin inhibits the nucleation mediated by AtFH8(FH1FH2) to some extent, but increases the rate of actin filament elongation in the presence of AtFH8(FH1FH2). Moreover, overexpression of the full-length AtFH8 in Arabidopsis causes a prominent change in root hair cell development and its actin organization, indicating the involvement of AtFH8 in polarized cell growth through the actin cytoskeleton.
Local Coexpression Domains of Two to Four Genes in the Genome of Arabidopsis
Authors: Ren Xin-Ying , Fiers Mark W.E.J. , Stiekema Willem J. , Nap Jan-Peter
Published: May 2005

Expression of genes in eukaryotic genomes is known to cluster, but cluster size is generally loosely defined and highly variable. We have here taken a very strict definition of cluster as sets of physically adjacent genes that are highly coexpressed and form so-called local coexpression domains. The Arabidopsis (Arabidopsis thaliana) genome was analyzed for the presence of such local coexpression domains to elucidate its functional characteristics. We used expression data sets that cover different experimental conditions, organs, tissues, and cells from the Massively Parallel Signature Sequencing repository and microarray data (Affymetrix) from a detailed root analysis. With these expression data, we identified 689 and 1,481 local coexpression domains, respectively, consisting of two to four genes with a pairwise Pearson's correlation coefficient larger than 0.7. This number is approximately 1- to 5-fold higher than the numbers expected by chance. A small (5%–10%) yet significant fraction of genes in the Arabidopsis genome is therefore organized into local coexpression domains. These local coexpression domains were distributed over the genome. Genes in such local domains were for the major part not categorized in the same functional category (GOslim). Neither tandemly duplicated genes nor shared promoter sequence nor gene distance explained the occurrence of coexpression of genes in such chromosomal domains. This indicates that other parameters in genes or gene positions are important to establish coexpression in local domains of Arabidopsis chromosomes.
The Arabidopsis Transcription Factor MYB12 Is a Flavonol-Specific Regulator of Phenylpropanoid Biosynthesis
Authors: Mehrtens Frank , Kranz Harald , Bednarek Pawel , Weisshaar Bernd
Published: May 2005

Comprehensive functional data on plant R2R3-MYB transcription factors is still scarce compared to the manifold of their occurrence. Here, we identified the Arabidopsis (Arabidopsis thaliana) R2R3-MYB transcription factor MYB12 as a flavonol-specific activator of flavonoid biosynthesis. Transient expression in Arabidopsis protoplasts revealed a high degree of functional similarity between MYB12 and the structurally closely related factor P from maize (Zea mays). Both displayed similar target gene specificity, and both activated target gene promoters only in the presence of a functional MYB recognition element. The genes encoding the flavonoid biosynthesis enzymes chalcone synthase, chalcone flavanone isomerase, flavanone 3-hydroxylase, and flavonol synthase were identified as target genes. Hence, our observations further add to the general notion of a close relationship between structure and function of R2R3-MYB factors. High-performance liquid chromatography analyses of myb12 mutant plants and MYB12 overexpression plants demonstrate a tight linkage between the expression level of functional MYB12 and the flavonol content of young seedlings. Quantitative real time reverse transcription-PCR using these mutant plants showed MYB12 to be a transcriptional regulator of CHALCONE SYNTHASE and FLAVONOL SYNTHASE in planta, the gene products of which are indispensable for the biosynthesis of flavonols.
The Involvement of Gibberellin 20-Oxidase Genes in Phytochrome-Regulated Petiole Elongation of Arabidopsis
Authors: Hisamatsu Tamotsu , King Rod W. , Helliwell Chris A. , Koshioka Masaji
Published: May 2005

Long day (LD) exposure of rosette plants causes rapid stem/petiole elongation, a more vertical growth habit, and flowering; all changes are suggestive of a role for the gibberellin (GA) plant growth regulators. For Arabidopsis (Arabidopsis thaliana) L. (Heynh), we show that enhancement of petiole elongation by a far-red (FR)-rich LD is mimicked by a brief (10 min) end-of-day (EOD) FR exposure in short day (SD). The EOD response shows red (R)/FR photoreversibility and is not affected in a phytochrome (PHY) A mutant so it is mediated by PHYB and related PHYs. FR photoconversion of PHYB to an inactive form activates a signaling pathway, leading to increased GA biosynthesis. Of 10 GA biosynthetic genes, expression of the 20-oxidase, AtGA20ox2, responded most to FR (up to a 40-fold increase within 3 h). AtGA20ox1 also responded but to a lesser extent. Stimulation of petiole elongation by EOD FR is reduced in a transgenic AtGA20ox2 hairpin gene silencing line. By contrast, it was only in SD that a T-DNA insertional mutant of AtGA20ox1 (ga5-3) showed reduced response. Circadian entrainment to a daytime pattern provides an explanation for the SD expression of AtGA20ox1. Conversely, the strong EOD/LD FR responses of AtGA20ox2 may reflect its independence of circadian regulation. While FR acting via PHYB increases expression of AtGA20ox2, other GA biosynthetic genes are known to respond to R rather than FR light and/or to other PHYs. Thus, there must be different signal transduction pathways, one at least showing a positive response to active PHYB and another showing a negative response.
Interaction between Phosphate-Starvation, Sugar, and Cytokinin Signaling in Arabidopsis and the Roles of Cytokinin Receptors CRE1/AHK4 and AHK3
Authors: Franco-Zorrilla José Manuel , Martín Ana Carmen , Leyva Antonio , Paz-Ares Javier
Published: May 2005

Cytokinins control key processes during plant growth and development, and cytokinin receptors CYTOKININ RESPONSE 1/WOODEN LEG/ARABIDOPSIS HISTIDINE KINASE 4 (CRE1/WOL/AHK4), AHK2, and AHK3 have been shown to play a crucial role in this control. The involvement of cytokinins in signaling the status of several nutrients, such as sugar, nitrogen, sulfur, and phosphate (Pi), has also been highlighted, although the full physiological relevance of this role remains unclear. To gain further insights into this aspect of cytokinin action, we characterized a mutant with reduced sensitivity to cytokinin repression of a Pi starvation-responsive reporter gene and show it corresponds to AHK3. As expected, ahk3 displayed reduced responsiveness to cytokinin in callus proliferation and plant growth assays. In addition, ahk3 showed reduced cytokinin repression of several Pi starvation-responsive genes and increased sucrose sensitivity. These effects of the ahk3 mutation were especially evident in combination with the cre1 mutation, indicating partial functional redundancy between these receptors. We examined the effect of these mutations on Pi-starvation responses and found that the double mutant is not significantly affected in long-distance systemic repression of these responses. Remarkably, we found that expression of many Pi-responsive genes is stimulated by sucrose in shoots and to a lesser extent in roots, and the sugar effect in shoots of Pi-starved plants was particularly enhanced in the cre1 ahk3 double mutant. Altogether, these results indicate the existence of multidirectional cross regulation between cytokinin, sugar, and Pi-starvation signaling, thus underlining the role of cytokinin signaling in nutrient sensing and the relative importance of Pi-starvation signaling in the control of plant metabolism and development.
Characterization of Markers to Determine the Extent and Variability of Leaf Senescence in Arabidopsis. A Metabolic Profiling Approach
Authors: Diaz Céline , Purdy Sarah , Christ Aurélie , Morot-Gaudry Jean-Francois , Wingler Astrid , Masclaux-Daubresse Céline
Published: May 2005

Comparison of the extent of leaf senescence depending on the genetic background of different recombinant inbred lines (RILs) of Arabidopsis (Arabidopsis thaliana) is described. Five RILs of the Bay-0 × Shahdara population showing differential leaf senescence phenotypes (from early senescing to late senescing) were selected to determine metabolic markers to discriminate Arabidopsis lines on the basis of senescence-dependent changes in metabolism. The proportion of γ-aminobutyric acid, leucine, isoleucine, aspartate, and glutamate correlated with (1) the age and (2) the senescence phenotype of the RILs. Differences were observed in the glycine/serine ratio even before any senescence symptoms could be detected in the rosettes. This could be used as predictive indicator for plant senescence behavior. Surprisingly, late-senescing lines appeared to mobilize glutamine, asparagine, and sulfate more efficiently than early-senescing lines. The physiological basis of the relationship between leaf senescence and flowering time was analyzed.
A Basic Helix-Loop-Helix Transcription Factor in Arabidopsis, MYC2, Acts as a Repressor of Blue Light–Mediated Photomorphogenic Growth
Authors: Yadav Vandana , Mallappa Chandrashekara , Gangappa Sreeramaiah N. , Bhatia Shikha , Chattopadhyay Sudip
Published: May 2005

The crosstalk of light signaling pathways with other signaling cascades has just started to be revealed. Here, we report the identification and functional characterization of a Z-box binding factor (ZBF1) in light signaling pathways. Arabidopsis thaliana  ZBF1 encodes AtMYC2/JIN1, a basic helix-loop-helix transcription factor, which has recently been shown to be involved in abscisic acid (ABA), jasmonic acid (JA), and jasmonate-ethylene signaling pathways. We demonstrate that AtMYC2 interacts with the Z- and G-box light-responsive elements of minimal light–regulated promoters. AtMYC2 is expressed in various light-grown seedlings, including in red, far red, and blue light. Genetic analyses suggest that AtMYC2 acts as a negative regulator of blue light–mediated photomorphogenic growth and blue and far-red-light–regulated gene expression; however, it functions as a positive regulator of lateral root formation. Our results further demonstrate that atmyc2 mutants have compromised sensitivity to ABA- and JA-mediated responses. Taken together, these results demonstrate that AtMYC2 is a common transcription factor of light, ABA, and JA signaling pathways in Arabidopsis.
Propranolol ameliorates and epinephrine exacerbates progression of acute and chronic viral myocarditis
Authors: Wang Ju-Feng , Meissner Achim , Malek Sohail , Chen Yu , Ke Qingen , Zhang Jielin , Chu Victor , Hampton Thomas G. , Crumpacker Clyde S. , Abelmann Walter H. , Amende Ivo , Morgan James P.
Published: May 2005

Recent studies point to important interactions between proinflammatory cytokines and neurohumoral mediators in heart failure. Here we investigate the influence of the β-adrenergic system on cytokines and neurohumoral factors and the sequelae of viral myocarditis. In an experimental model with virus-infected BALB/c mice, we studied the acute and chronic effects of epinephrine and propranolol on myocardial morphology, cytokine gene expression, and survival. BALB/c mice were inoculated with the encephalomyocarditis virus (EMCV) or sham inoculated with saline and followed for 30 days. Epinephrine increased the severity of inflammatory cell infiltration and myocardial necrosis induced by EMCV. Gene expression of TNF-α, IL-6, and IL-10 was markedly enhanced by epinephrine in EMCV-inoculated mice. Survival rate after 30 days was reduced to 40% in epinephrine-treated EMCV-inoculated mice compared with 70% in untreated EMCV-inoculated mice ( P < 0.05). Treatment with the β-blocker propranolol significantly decreased mortality, myocardial necrosis, and infiltration of inflammatory cells in EMCV-inoculated mice. Propranolol also suppressed gene expression of TNF-α, IL-6, and IL-10. A single dose of epinephrine 120 days after EMCV inoculation caused sudden death in 70% of infected mice; propranolol significantly reduced incidence of death to 33%. These results indicate that acute and chronic stages of viral myocarditis are modulated by the β-adrenergic system and its interactions with proinflammatory cytokines.
Right and left ventricular adaptation to hypoxia: a tissue Doppler imaging study
Authors: Huez Sandrine , Retailleau Kathleen , Unger Philippe , Pavelescu Adriana , Vachiéry Jean-Luc , Derumeaux Geneviève , Naeije Robert
Published: May 2005

Hypoxia has been reported to alter left ventricular (LV) diastolic function, but associated changes in right ventricular (RV) systolic and diastolic function remain incompletely documented. We used echocardiography and tissue Doppler imaging to investigate the effects on RV and LV function of 90 min of hypoxic breathing (fraction of inspired O2of 0.12) compared with those of dobutamine to reproduce the same heart rate effects without change in pulmonary vascular tone in 25 healthy volunteers. Hypoxia and dobutamine increased cardiac output and tricuspid regurgitation velocity. Hypoxia and dobutamine increased LV ejection fraction, isovolumic contraction wave velocity (ICV), acceleration (ICA), and systolic ejection wave velocity (S) at the mitral annulus, indicating increased LV systolic function. Dobutamine had similar effects on RV indexes of systolic function. Hypoxia did not change RV area shortening fraction, tricuspid annular plane systolic excursion, ICV, ICA, and S at the tricuspid annulus. Regional longitudinal wall motion analysis revealed that S, systolic strain, and strain rate were not affected by hypoxia and increased by dobutamine on the RV free wall and interventricular septum but increased by both dobutamine and hypoxia on the LV lateral wall. Hypoxia increased the isovolumic relaxation time related to RR interval (IRT/RR) at both annuli, delayed the onset of the E wave at the tricuspid annulus, and decreased the mitral and tricuspid inflow and annuli E/A ratio. We conclude that hypoxia in normal subjects is associated with altered diastolic function of both ventricles, improved LV systolic function, and preserved RV systolic function.
Maturation enhances fluid shear-induced activation of eNOS in perfused ovine carotid arteries
Authors: White Charles Ray , Hamade Mohammad Wael , Siami Koushan , Chang Melody M. , Mangalwadi Anandit , Frangos John A. , Pearce William J.
Published: May 2005

The present study tests the hypothesis that age-dependent increases in endothelial vasodilator capacity are due to maturational increases in endothelial nitric oxide (NO) synthesis and release. Intact 4-cm carotid artery segments taken from term fetal lambs and nonpregnant adult sheep were perfused by using a closed system that enabled independent control of flow and inflow pressure and facilitated complete recovery of all NO released. Fluid shear stress induced a graded release of NO (in nmol NO·min·cm−2of luminal surface area) that was significantly greater in adult (890 ± 140) than in fetal (300 ± 40) carotid arteries at corresponding values of shear stress (5.9 ± 0.3 dyn/cm2) but was independent of inflow pressure in both age groups. These age-related differences in NO release were not attributable to corresponding differences in endothelial NO synthase (eNOS) abundance, as eNOS protein levels (in ng of eNOS/cm2of luminal surface area) were similar in adult (14 ± 2) and fetal (12 ± 1) arteries. Adult (80 ± 15) and fetal (89 ± 32) levels of eNOS mRNA (in 106copies/cm2of luminal surface area) were also similar. However, when NO release was normalized relative to the associated mass of eNOS protein to estimate eNOS-specific activity in situ, this value (in nmol NO·μg of eNOS−1·min−1) was significantly greater in adult (177 ± 44) than in fetal (97 ± 36) arteries when the endothelium was maximally activated by A-23187. Similarly, the slope of the relation between fluid shear stress and estimated eNOS-specific activity (in nmol NO·μg of eNOS−1·min−1per dyn/cm2) was also significantly greater in adult (6.8 ± 0.1) than in fetal (2.9 ± 0.1) arteries, which suggests that eNOS may be more sensitive to or more efficiently coupled to activating stimuli in adult compared with fetal arteries. We conclude that maturational increases in endothelial vasodilator capacity are attributable to age-dependent increases in NO release secondary to elevated eNOS-specific activity and involve more efficient coupling between endothelial activation and enhancement of eNOS activity in adult compared with fetal arteries.
Estrogen regulates β1-subunit expression in Ca2+-activated K+channels in arteries from reproductive tissues
Authors: Nagar Deepa , Liu Xiao-tie , Rosenfeld Charles R.
Published: May 2005

Daily estradiol-17β (E2β) increases basal uterine blood flow (UBF) and enhances acute E2β-mediated increases in UBF in ovariectomized nonpregnant ewes. The acute E2β-mediated rise in UBF involves vascular smooth muscle (VSM) large-conductance Ca2+-activated K+channels (BKCa). BKCaconsist of pore-forming α-subunits and regulatory β1-subunits that modulate channel function and E2β responsiveness. It is unclear whether E2β also alters subunit expression and thus channel density and/or function, thereby contributing to the rise in basal UBF and enhanced UBF responses that follow daily E2β. Therefore, we examined BKCasubunit expression by using reverse transcription-PCR and immunoblot analysis of arterial VSM from reproductive and nonreproductive tissues and myometrium from ovariectomized nonpregnant ewes after daily E2β (1 μg/kg iv) or vehicle without or with acute E2β (1 μg/kg). Tissue distribution was determined by immunohistochemistry. Acute E2β did not alter α- or β1-subunit expression in any tissue ( P > 0.1). Daily E2β also did not affect α-subunit mRNA or protein in any tissue ( P > 0.1) or mesenteric arterial VSM β1-subunit. However, daily E2β increased uterine and mammary arterial VSM β1-subunit mRNA by 32% and 83% ( P < 0.05), uterine VSM protein by 30%, and myometrial β1-subunit mRNA and protein by 74% ( P ≤ 0.005). Immunostaining of uterine arteries, myometrium, and intramyometrial arteries paralleled immunoblot analyses for both subunits. Although BKCadensity is unaffected by daily and acute E2β, daily E2β increases β1-subunit in proximal and distal uterine arterial VSM. Thus prolonged E2β exposure may alter BKCafunction, estrogen responsiveness, and basal vascular tone and reactivity in reproductive arteries by modifying α:β1stoichiometry.
Neural-Cardiac Coupling in Threat-Evoked Anxiety
Authors: Dalton Kim M. , Kalin Ned H. , Grist Thomas M. , Davidson Richard J.
Published: May 2005

Anxiety is a debilitating symptom of many psychiatric disorders including generalized anxiety disorder, mood disorders, schizophrenia, and autism. Anxiety involves changes in both central and peripheral biology, yet extant functional imaging studies have focused exclusively on the brain. Here we show, using functional brain and cardiac imaging in sequential brain and cardiac magnetic resonance imaging (MRI) sessions in response to cues that predict either threat (a possible shock) or safety (no possibility of shock), that MR signal change in the amygdala and the prefrontal and insula cortices predicts cardiac contractility to the threat of shock. Participants with greater MR signal change in these regions show increased cardiac contractility to the threat versus safety condition, a measure of the sympathetic nervous system contribution to the myocardium. These findings demonstrate robust neural-cardiac coupling during induced anxiety and indicate that individuals with greater activation in brain regions identified with aversive emotion show larger magnitude cardiac contractility increases to threat.
Priming of Color and Position during Visual Search in Unilateral Spatial Neglect
Authors: Kristjánsson Árni , Vuilleumier Patrik , Malhotra Paresh , Husain Masud , Driver Jon
Published: May 2005

We examined priming of visual search by repeated target location or color in two patients with left visual neglect and extinction, following strokes centered on the right inferior parietal lobe. Both patients, like the healthy controls we tested, showed intact priming, with performance speeded when either the location or color of a singleton target was repeated over successive trials in a standard search condition (Experiment 1). This was observed both from and to targets on the contralesional (left) side. Moreover, priming of search was still observed even when a return of fixation back to display-center was required between successive trials (Experiment 2). When briefer displays were used (Experiment 3), the patients often failed to detect left targets. This situation revealed an important dissociation: Whereas location priming only arose from preceding left targets that had been consciously detected, color priming (possibly arising within the intact ventral stream) did not depend on awareness of the preceding target. There was considerable color priming from missed targets. These findings demonstrate relatively intact priming of visual search by color and location in patients with right parietal damage, and also reveal that location priming may differ from color priming in requiring awareness.
Hellenistic Instruction in Palestine and Egypt: Ben Sira and Papyrus Insinger
Authors: Goff Matthew
Published: May 2005

Ben Sira and the Demotic wisdom text Papyrus Insinger have numerous similarities. This is evident in terms of their practical instruction on topics such as shame, generosity, and moderation. They also have affinities regarding more speculative concerns, including theodicy and the nature of the cosmos. These affinities can often be attributed to the fact that each work draws on the native wisdom traditions of its own country, and there are broad similarities between the traditional wisdom of Israel and Egypt. Some of the points of contact between Ben Sira and Papyrus Insinger also reflect intellectual trends of the Hellenistic age.
The Letter of Aristeas: A New Exodus Story?
Authors: Hacham Noah
Published: May 2005

A common opinion views the purpose of the Letter of Aristeas as strengthening the self-identity of Egyptian Diaspora Jewry by sanctifying the Greek translation of the Torah. As Orlinsky has shown, this view is supported by linguistic and thematic parallels between Aristeas and biblical descriptions of the giving of the Torah. The linguistic and thematic associations, however, do not only apply to this specific biblical episode, but also to the entire book of Exodus including the exodus story itself. The author of Aristeas transformed the biblical stories of the exodus and the giving of the Torah into a new foundation story of Egyptian Jewry. In doing so, the new story disregards the biblical hostility to Egypt and instead expresses sympathy for the Ptolemaic king who released the Jews from slavery, settled them in Egypt and initiated the Torah translation into Greek. The aim of Aristeas was to offer a religious justification for the residence of Jews in Egypt.
Tree thinning as an option to increase herbaceous yield of an encroached semi-arid savanna in South Africa
Authors: Smit Gert N
Published: May 2005

Background

The investigation was conducted in a savanna area covered by what was considered an undesirably dense stand of Colophospermum mopane trees, mainly because such a dense stand of trees often results in the suppression of herbaceous plants. The objectives of this study were to determine the influence of intensity of tree thinning on the dry matter yield of herbaceous plants (notably grasses) and to investigate differences in herbaceous species composition between defined subhabitats (under tree canopies, between tree canopies and where trees have been removed). Seven plots (65 × 180 m) were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0 %) to plots thinned to the equivalent of 10 %, 20%, 35 %, 50% and 75 % of the leaf biomass of a control plot (100 %) with a tree density of 2711 plants ha-1. The establishment of herbaceous plants (grasses and forbs) in response to reduced competition from the woody plants was measured during three full growing seasons following the thinning treatments.

Results

The grass component reacted positively to the tree thinning in terms of total dry matter (DM) yield, but forbs were negatively influenced. Rainfall interacted with tree density and the differences between grass DM yields in thinned plots during years of below average rainfall were substantially higher than those of the control. At high tree densities, yields differed little between seasons of varying rainfall. The relation between grass DM yield and tree biomass was curvilinear, best described by the exponential regression equation. Subhabitat differentiation by C. mopane trees did provide some qualitative benefits, with certain desirable grass species showing a preference for the subhabitat under tree canopies.

Conclusion

While it can be concluded from this study that high tree densities suppress herbaceous production, the decision to clear/thin the C. mopane trees should include additional considerations. Thinning of C. mopane with the exclusive objective of increasing productivity of the grass layer would thus invariably involve a compromise situation where some trees should be left for the sake of the qualitative benefits on the herbaceous layer, soil enrichment, provision of browse and stability of the ecosystem.
Centaurin-α1 interacts directly with kinesin motor protein KIF13B
Authors: Venkateswarlu Kanamarlapudi , Hanada Toshihiko , Chishti Athar H.
Published: May 2005

Centaurin-α1 is a phosphatidylinositol 3,4,5-trisphosphate binding protein as well as a GTPase activating protein (GAP) for the ADP-ribosylation factor (ARF) family of small GTPases. To further understand its cellular function, we screened a rat brain cDNA library using centaurin-α1 as bait to identify centaurin-α1 interacting proteins. The yeast two-hybrid screen identified a novel kinesin motor protein as a centaurin-α1 binding partner. The motor protein, termed KIF13B, encoded by a single ∼9.5-kb transcript, is widely expressed with high levels observed in brain and kidney. Yeast two-hybrid and GST pull-down assays showed that the interaction between centaurin-α1 and KIF13B is direct and mediated by the GAP domain of centaurin-α1 and the stalk domain of KIF13B. Centaurin-α1 and KIF13B form a complex in vivo and the KIF13B interaction appears to be specific to centaurin-α1 as other members of the ARF GAP family did not show any binding activity. We also show that KIF13B and centaurin-α1 colocalize at the leading edges of the cell periphery whereas a deletion mutant of centaurin-α1 that lacks the KIF13B binding site, failed to colocalize with KIF13B in vivo. Finally, we demonstrate that KIF13B binding suppresses the ARF6 GAP activity of centaurin-α1 in intact cells. Together, our data suggest a mechanism where direct binding between centaurin-α1 and KIF13B could concentrate centaurin-α1 at the leading edges of cells, thus modulating ARF6 function.
TRPV4 exhibits a functional role in cell-volume regulation
Authors: Becker Daniel , Blase Christopher , Bereiter-Hahn Juergen , Jendrach Marina
Published: May 2005

Tight regulation of the cell volume is important for the maintenance of cellular homeostasis. In a hypotonic environment, cells swell owing to osmosis. With many vertebrate cells, swelling is followed by an active reduction of volume, a process called regulatory volume decrease (RVD). A possible participant in RVD is the non-selective cation channel TRPV4, a member of the TRP superfamily that has been shown to react to hypotonic stimuli with a conductance for Ca2+. As a model for cell-volume regulation, we used a human keratinocyte cell line (HaCaT) that produces TRPV4 endogenously. When HaCaT cells were exposed to a hypotonic solution (200 mOsm) maximal swelling was followed by RVD. During swelling and volume regulation, a strong Ca2+ influx was measured. Gd3+, an inhibitor of TRPV4, blocked RVD of HaCaT cells and the accompanying rise of cytosolic Ca2+. To define the role of TRPV4 in volume regulation, a TRPV4-EGFP fusion protein was produced in CHO cells. CHO cells are unable to undergo RVD under hypotonic conditions and do not produce TRPV4 endogenously. Fluorescence imaging revealed that recombinant TRPV4 was localized to the cell membrane. Production of TRPV4 enabled CHO cells to undergo typical RVD after hypo-osmolarity-induced cell swelling. RVD of TRPV4-transfected CHO cells was significantly reduced by Gd3+ treatment or in Ca2+-free solution. Taken together, these results show a direct participation of TRPV4 in RVD.
Neuronal Ca2+ sensor protein VILIP-1 affects cGMP signalling of guanylyl cyclase B by regulating clathrin-dependent receptor recycling in hippocampal neurons
Authors: Brackmann Marian , Schuchmann Sebastian , Anand Rene , Braunewell Karl-Heinz
Published: May 2005

The family of neuronal Ca2+ sensor (NCS) proteins is known to influence a variety of physiological and pathological processes by affecting signalling of different receptors and ion channels. Recently, it has been shown that the NCS protein VILIP-1 influences the activity of the receptor guanylyl cyclase GC-B. In transfected cell lines, VILIP-1 performs a Ca2+-dependent membrane association, the reversible Ca2+-myristoyl switch of VILIP-1, which leads to an increase in natriuretic peptide-stimulated cGMP levels. In this study, we have investigated the effect of VILIP-1 on cGMP signalling in C6 cells and in primary hippocampal neurons, where VILIP-1 and GC-B are co-expressed in many but not all neurons and partially co-localize in the soma and in dendrites. Our data indicate that VILIP-1 modulates GC-B activity by influencing clathrin-dependent receptor recycling. These data support a general physiological role for VILIP-1 in membrane trafficking in the intact hippocampus, where the NCS protein may affect processes, such as neuronal differentiation and synaptic plasticity e.g. by influencing cGMP-signalling.
New insights into Fat cadherins
Authors: Tanoue Takuji , Takeichi Masatoshi
Published: May 2005

Cell-cell adhesion is fundamental to multicellular architecture. Several classes of adhesion molecule are used to achieve this, and cadherins represent a major family of such molecules. The cadherin family has multiple subfamilies. Members of the Fat cadherin subfamily, which is conserved across species, have an extraordinarily large extracellular region, comprising 34 repeated domains, making them the largest cadherin molecules. Classic Fat, identified in Drosophila, is known to regulate cell proliferation and planar cell polarity. Recent studies of one of its mammalian homologs, Fat1, have revealed novel functions of this molecule. Fat1 binds to Ena/VASP proteins and regulates actin dynamics at both cell-cell contacts and leading edges. These observations suggest that Fat1 is an important regulator of actin dynamics and controls cell-cell interactions through this activity.
Endovascular embolization of a traumatic arteriovenous fistula of the superficial temporal artery
Authors: Whiteside O J H , Monksfield P , Steventon N B , Byrne J , Burton M J
Published: May 2005

Arteriovenous fistula of the superficial temporal artery is a rare condition most commonly caused by trauma. Traditional surgical treatment has been superseded by endovascular embolization. We present the case of a 40year-old man with a traumatic arteriovenous fistula of the superficial temporal artery who was treated by endovascular embolization. The advantages of this approach are discussed, along with a brief history of the condition
Student-perceived benefit from otolaryngology theatre attendance
Authors: Lee M S W , Montague M-L , Hussain S S M
Published: May 2005

The value of theatre attendance by undergraduates is uncertain. This study aimed to evaluate the perceived benefits of attending operating theatre sessions during undergraduate otolaryngology attachments. The study comprised a questionnaire survey carried out in a university medical school. Fourth-year medical students were asked to complete a questionnaire at the end of their two-week attachment in otolaryngology. Completed questionnaires were returned by 152 students. The three most common student expectations were to see and learn common ENT operations, to see the anatomy involved and to learn about the disease being operated upon. Sixty per cent of students reported that their expectations had been met. On a Likert scale from 1 (strongly disagree) to 7 (strongly agree), the importance of theatre attendance as part of the curriculum was rated to be 4.7 (95 per cent confidence interval (CI) = 3.7 to 4.2) and the satisfaction of educational needs in operating theatre teaching was rated to be 3.9 (95 per cent CI = 3.7 to 4.2). Students perceived attending otolaryngology theatre sessions to be beneficial. This information is important in the planning of the otolaryngology undergraduate curriculum.
Critical clinical appraisal of the role of ultrasound guided fine needle aspiration cytology in the management of parotid tumours
Authors: Bajaj Y , Singh S , Cozens N , Sharp J
Published: May 2005

Objective: Fine needle aspiration cytology is a well established tool for investigating many head and neck conditions. Its application in parotid tumours is, however, controversial. This article is aimed at defining the role of ultrasound guided fine needle aspiration cytology (FNAC) in the diagnostic work up of parotid tumours. The accuracy and utility of FNAC of parotid tumours was also assessed.

Design: Retrospective case note review.

Setting: District general hospital.

Participants: Review of 69 patient records who had parotid surgery under one surgeon’s care (JS). Clinical opinion, FNAC results and final pathology findings were examined.

Main outcome measures: The results of the FNAC were compared to the histopathological diagnosis obtained from the surgical specimen.

Results: Histological evaluation revealed 13 malignant tumours and 56 benign lesions. The overall sensitivity of FNAC was 84.6 per cent and specificity was 96.4 per cent. We noted 11 true positive, 54 true negative, two false negative and two false positive results. Positive predictive value for diagnosing malignancy was 84.6 per cent and negative predictive value for malignancy was 96.4 per cent. The overall accuracy of FNAC of parotids in this study was 94.2 per cent.

Conclusions: FNAC results provide useful preoperative information. FNAC enables more reliable patient counselling and reduces pathological surprises. Pre-operative recognition of malignant tumours may help prepare both the surgeon and patient for an appropriate surgical procedure. Its enhancement of the pre-operative recognition of malignant parotid tumours may alert more stringent attention to the operative margin and hence better tumour clearance. Ultrasound guided FNAC was found to be highly specific for malignancy and its sensitivity for malignancy was good.