bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluffy, the major regulator of conidiation in Neurospora crassa, directly activates a developmentally regulated hydrophobin gene
Authors: Rerngsamran Panan , Murphy Michael B. , Doyle Sharon A. , Ebbole Daniel J. 
Published: March 2005

SummaryThe fluffy (fl) gene of Neurospora crassa is required for asexual sporulation and encodes an 88 kDa polypeptide containing a typical fungal Zn2Cys6 DNA‐binding motif. Identification of genes regulated by fl will provide insight into how fungi regulate growth during morphogenesis. As a step towards identifying the target genes on which FL may act, we sought to define target sequences to which the FL protein binds. The DNA binding domain of FL was expressed in Escherichia coli as a fusion with glutathione S‐transferase (GST) and purified using glutathione‐sepharose affinity chromatography. The DNA binding sites were selected and amplified by means of a polymerase chain reaction (PCR)‐mediated random‐site selection method involving affinity bead‐binding and gel mobility shift analysis. Sequencing and comparison of the selected clones suggested that FL binds to the motif 5′‐CGG(N)9CCG‐3′. A potential binding site was found in the promoter region of the eas (ccg‐2) gene, which encodes a fungal hydrophobin. In vitro competitive binding assays revealed a preferred binding site for FL in the eas promoter, 5′‐CGGAAGTTTC CTCCG‐3′, which is located 1498 bp upstream of the eas translation initiation codon. In vivo experiments using a foreign DNA sequence tag also confirmed that this sequence resides in a region required for FL regulation. In addition, yeast one hybrid experiments demonstrated that the C‐terminal portion of FL functions in transcriptional activation. Transcriptional profiling was used to identify additional potential targets for regulation by fl.
Four conserved intramolecular disulphide linkages are required for secretion and cell wall localization of a hydrophobin during fungal morphogenesis
Authors: Kershaw Michael J. , Thornton Christopher R. , Wakley Gavin E. , Talbot Nicholas J. 
Published: March 2005

SummaryHydrophobins are morphogenetic proteins produced by fungi during assembly of aerial hyphae, sporulation, mushroom development and pathogenesis. Eight cysteine residues are present in hydrophobins and form intramolecular disulphide bonds. Here, we show that expressing eight cysteine–alanine substitution alleles of theMPG1hydrophobin gene fromMagnaporthe griseacauses severe defects in development of aerial hyphae and spores. Immunolocalization revealed that Mpg1 hydrophobin variants, lacking intact disulphide bonds, retain the capacity to self‐assemble, but are not secreted to the cell surface. This provides the first genetic evidence that disulphide bridges in a hydrophobin are dispensable for aggregation, but essential for secretion.
Evaluation of gastric emptying by electrogastrography and ultrasonography in gastroesophageal reflux disease
Authors: Kujime Sae , Inoue Syuji , Nomura Masahiro , Endo Jyunko , Uemura Nobutaka , Kishi Seiichiro , Nakaya Yutaka , Ito Susumu 
Published: March 2005

Background: It has been suggested that transient lower esophageal sphincter relaxation is involved in the occurrence of gastroesophageal reflux disease (GERD) and that decreased gastric emptying is an exacerbating factor of transient LES relaxation. In addition, the gastric emptying function is considered to be closely related to gastric motility.Methods: Gastric activity was evaluated by electrogastrography (EGG) in 22 patients with endoscopically positive reflux esophagitis (15 with mild esophagitis of Los Angeles grade A or B and seven with severe esophagitis of Los Angeles grade C or D) and 20 normal individuals. The gastric emptying function was also evaluated by abdominal ultrasonography. The sampling cycle of EGG was 1 s, and the measured frequency was 2.1–6.0 cycle/min (c.p.m.). The mean amplitude of EGG was compared by EGG spectral analysis among brady‐gastria cases with a contraction frequency of less than 2.4 c.p.m., normo‐gastria cases with a contraction frequency of 2.4–3.6 c.p.m., and tachy‐gastria cases with a contraction frequency exceeding 3.6 c.p.m.Results: In the patients with GERD, both the frequency of 3‐c.p.m. waves and peak frequency were reduced, and the gastric emptying function examined by ultrasonography had deteriorated, in comparison with normal individuals. Of those with GERD, the ultrasonographic gastric emptying function was significantly reduced in all patients with severe esophagitis compared with those with mild esophagitis, but the differences of the frequency of 3‐c.p.m. waves, the peak frequency, were not significant. Also, no significant difference was observed in the frequency of 3‐c.p.m. waves or the ultrasonographic gastric emptying function between the 16 patients with hiatal hernia and the six patients with no hiatal hernia. However, the mean amplitude in brady‐gastria and tachy‐gastria was significantly increased in the patients with hiatal hernia compared to those without hiatal hernia.Conclusions: Reduced gastric motility was suggested to be involved in the development of reflux esophagitis, and the presence of hiatal hernia was considered to have some effect on gastric motility.
Predictors of a response to cyclosporine or leukocyte removal therapy in patients with refractory ulcerative colitis
Authors: Ando Takafumi , Watanabe Osamu , Furuta Ryuichi , Maeda Osamu , Nishio Yuji , Nishiwaki Tsuyoshi , Ina Kenji , Kusugami Kazuo , Goto Hidemi 
Published: March 2005

Introduction: Despite decades of clinical experience in optimizing the induction and maintenance of remission in patients with ulcerative colitis (UC), some patients remain refractory to conventional medical treatment while, in others, the effectiveness of drugs is limited by side‐effects. We investigated factors predictive of the efficacy of cyclosporine and leukocyte removal therapy in patients with intractable UC.Methods: Forty‐five patients with moderate to severe UC who were refractory to corticosteroid therapy were enrolled. Twenty‐six patients were treated with cyclosporine and 19 by leukocyte removal therapy. Disease activity index (DAI) score assessment, and colonoscopic and histological examinations were done before and at 10, 20 and 40 days after the initiation of treatment. A clinical response to treatment was defined as a decrease in DAI score of 3 points or more at 40 days.Results: Responder ratio did not significantly differ between the cyclosporine (65.6%) and leukocyte removal therapy (63.2%) groups. Factors predictive of a response to cyclosporine therapy were fever (≥ 38.0°C), anemia and large mucosal ulceration. In contrast, mucosal bleeding and poor extensibility of the intestinal lumen were predictive of a poor response to cyclosporine. No significant differences in any clinical or endoscopic parameter predictive of a response to leukocyte removal therapy were identified.Conclusions: Intravenous cyclosporine may be effective in patients who have severe steroid‐refractory UC, and leukocyte removal therapy may be useful in patients with moderate active UC predicted to be refractive to cyclosporine.
Bi‐hemispheric contribution to functional motor recovery of the affected forelimb following focal ischemic brain injury in rats
Authors: Biernaskie Jeff , Szymanska Aleksandra , Windle Victoria , Corbett Dale 
Published: March 2005

AbstractIn many recovering hemiparetic stroke patients, movement of the affected limb elicits ipsilateral activation of sensorimotor areas within the undamaged hemisphere, which is not observed in control subjects. Following middle cerebral artery occlusion, rats received intensive enriched‐rehabilitation (ER) of the impaired forelimb for 4 weeks. Weekly assessments on a skilled reaching test demonstrated significant improvement in ischemic animals over 4 weeks of ER (P < 0.05). We hypothesized that if the undamaged forelimb motor cortex contributed to improved forelimb function, then inhibition of neural activity within this region should reinstate (at least some of) the initial motor impairment. After 3 and 4 weeks of ER, animals received a microinjection of lidocaine hydrochloride into the undamaged motor cortex and were re‐assessed on reaching ability. The behavioral effect of lidocaine challenge was dependent on the size of the infarct: animals with large infarcts were rendered unable to retrieve any food pellets and had great difficulty even contacting a pellet with the affected forepaw. Small‐infarct animals were only moderately affected (25% reduction in success) by lidocaine, an effect similar to that observed in control animals. Qualitative assessments of recovered reaching after 4 weeks of rehabilitation revealed that impairments in forelimb lift, advance and aim were exacerbated (P < 0.05) following lidocaine‐inactivation of the undamaged motor cortex of animals with large ischemic infarcts. In animals with small infarcts, lidocaine challenge only impaired limb advance. Thus, recruitment of the undamaged hemisphere may depend on the functional integrity of the remaining sensorimotor system. These data suggest that, in the rat, the undamaged (ipsilateral) motor system may contribute to compensatory recovery of the affected forelimb.
α‐Amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionate receptor autoradiography in mouse brain after single and repeated withdrawal from diazepam
Authors: Allison C. , Pratt J. A. , Ripley T. L. , Stephens D. N. 
Published: March 2005

AbstractWithdrawal from chronic treatment with benzodiazepines is associated with increased neuronal excitability leading to anxiety, aversive effects and increased seizure sensitivity. After repeated withdrawal experiences, seizure sensitivity increases while withdrawal‐induced anxiety and aversion decrease. We used autoradiographical methods employing [3H]Ro48 8587, a selective ligand for glutamatergic α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionate (AMPA) receptors, to study withdrawal‐induced changes in AMPA receptor binding in areas of the mouse brain postulated to be involved in these responses. Mice were given 21 days treatment with diazepam (15 mg/kg, s.c. in sesame oil) followed by withdrawal (single withdrawal) or three blocks of 7 days treatment interspersed with 3‐day periods to allow washout of drug (repeated withdrawal). In keeping with heightened excitability in withdrawal from chronic diazepam treatment, the single withdrawal group showed, 72 h after their final dose of diazepam, increased [3H]Ro48 8587 binding in several brain areas associated with emotional responses or seizure activity, including hippocampal subfields, amygdalar and thalamic nuclei and motor cortex. In contrast, the repeated withdrawal group showed no changes in [3H]Ro48 8587 binding in any brain area studied. These observations are consistent with up‐regulation of AMPA receptor‐mediated transmission being important in withdrawal‐induced anxiety and aversion but not in increased seizure sensitivity associated with repeated withdrawal. As changes in AMPA receptor subunit expression alter the functionality of the receptor, future studies will address this possibility.
SHORT COMMUNICATIONS: Semantic memory retrieval: cortical couplings in object recognition in the N400 window
Authors: Supp Gernot G. , Schlögl Alois , Fiebach Christian J. , Gunter Thomas C. , Vigliocco Gabriella , Pfurtscheller Gert , Petsche Hellmuth 
Published: March 2005

AbstractTo characterize the regional changes in neuronal couplings and information transfer related to semantic aspects of object recognition in humans we used partial‐directed EEG‐coherence analysis (PDC). We examined the differences of processing recognizable and unrecognizable pictures as reflected by changes in cortical networks within the time‐window of a determined event‐related potential (ERP) component, namely the N400. Fourteen participants performed an image recognition task, while sequentially confronted with pictures of recognizable and unrecognizable objects. The time‐window of N400 as indicative of object semantics was defined from the ERP. Differences of PDC in the beta‐band between these tasks were represented topographically as patterns of electrical couplings, possibly indicating changing degrees of functional cooperation between brain areas. Successful memory retrieval of picture meaning appears to be supported by networks comprising left temporal and parietal regions and bilateral frontal brain areas.
Differential effects of forskolin on tyrosine hydroxylase gene transcription in identified brainstem catecholaminergic neuronal subtypes in organotypic culture
Authors: Rusnak Milan , Gainer Harold 
Published: March 2005

AbstractThe regulation of gene expression of tyrosine hydroxylase (TH), the rate‐limiting enzyme in catecholamine synthesis, was studied in brainstem noradrenergic nuclei, locus coeruleus (LC), A2 and A1, in vitro. Several novel experimental approaches employed in this study included: (i) the development of a slice‐explant model in which these brainstem nuclei maintained a high survival of the noradrenergic neurons, an organotypic topology and the coexpression of two identifying markers in addition to TH, i.e. norepinephrine transporter (NET) and vesicular monoamine transporter 2 (VMAT2); (ii) quantitative analysis of TH transcription in these nuclei was made using a labelled intronic probe to measure TH heteronuclear RNA (hnRNA) and (iii) the use of tetrodotoxin in the media to eliminate spontaneous neural activity in these nuclei, thereby providing a basal state as the starting point for the study of TH transcription under various pharmacological perturbations. In the presence of TTX, the adenylcyclase stimulator, forskolin, produced a 155% increase in LC, a 130% increase in A1, and a 220% increase in A2 in TH hnRNA as compared to control nuclei. This effect of forskolin was abolished in the LC and A1 by the PKA inhibitor, H89 (5 µm), but not by the MAP kinase pathway (MEK) inhibitor, PD98059 (75 µm). In contrast, the robust increase in TH transcription produced by forskolin in A2 neurons, was completely inhibited by PD98059, and only partially inhibited by H89, showing that induced TH transcription is mediated by different kinase pathways in specific central noradrenergic neuronal subtypes.
Attending to visual or auditory motion affects perception within and across modalities: an event‐related potential study
Authors: Beer Anton L. , Röder Brigitte 
Published: March 2005

AbstractThe present event‐related potential (ERP) study examined the role of dynamic features in multisensory binding. It was tested whether endogenous attention to the direction of motion affects processing of visual and auditory stimuli within and across modalities. Human participants perceived horizontally moving dot patterns and sounds that were presented either continuously (standards) or briefly interrupted (infrequent deviants). Their task was to detect deviants moving in a particular direction within a primary modality, but to detect all deviants irrespective of their motion direction within the secondary modality. Attending to the direction of visual motion resulted in a broad selection negativity (SN) starting at about 200 ms post‐stimulus onset, and attending to the direction of auditory motion resulted in a positive difference wave at 150 ms that was followed by a broad negativity starting at about 200 ms (unimodal effects). Moreover, dot patterns moving in a direction that was attended within audition were detected faster and more accurately than oppositely moving stimuli and elicited a cross‐modal SN wave. Corresponding cross‐modal behavioural and ERP results were obtained for sounds moving in a direction that was attended within vision. Unimodal and cross‐modal ERP attention effects partially differed in their scalp topography. The present study shows that dynamic features (direction of motion) may be used to link input across modalities and demonstrates for the first time that these multisensory interactions take place as early as about 200 ms after stimulus onset.
Exposure to pulse‐modulated radio frequency electromagnetic fields affects regional cerebral blood flow
Authors: Huber R. , Treyer V. , Schuderer J. , Berthold T. , Buck A. , Kuster N. , Landolt H. P. , Achermann P. 
Published: March 2005

AbstractWe investigated the effects of radio frequency electromagnetic fields (RF EMF) similar to those emitted by mobile phones on waking regional cerebral blood flow (rCBF) in 12 healthy young men. Two types of RF EMF exposure were applied: a ‘base‐station‐like’ and a ‘handset‐like’ signal. Positron emission tomography scans were taken after 30 min unilateral head exposure to pulse‐modulated 900 MHz RF EMF (10 g tissue‐averaged spatial peak‐specific absorption rate of 1 W/kg for both conditions) and sham control. We observed an increase in relative rCBF in the dorsolateral prefrontal cortex on the side of exposure. The effect depended on the spectral power in the amplitude modulation of the RF carrier such that only ‘handset‐like’ RF EMF exposure with its stronger low‐frequency components but not the ‘base‐station‐like’ RF EMF exposure affected rCBF. This finding supports our previous observation that pulse modulation of RF EMF is necessary to induce changes in the waking and sleep EEG, and substantiates the notion that pulse modulation is crucial for RF EMF‐induced alterations in brain physiology.
Somatodendritic autoreceptor regulation of serotonergic neurons: dependence on l‐tryptophan and tryptophan hydroxylase‐activating kinases
Authors: Liu Rong‐Jian , Lambe Evelyn K. , Aghajanian George K. 
Published: March 2005

AbstractThe somatodendritic 5‐HT1A autoreceptor has been considered a major determinant of the output of the serotonin (5‐HT) neuronal system. However, recent studies in brain slices from the dorsal raphe nucleus have questioned the relevance of 5‐HT autoinhibition under physiological conditions. In the present study, we found that the difficulty in demonstrating 5‐HT tonic autoinhibition in slice results from in vitro conditions that are unfavorable for sustaining 5‐HT synthesis. Robust, tonic 5‐HT1A autoinhibition can be restored by reinstating in vivo 5‐HT synthesizing conditions with the initial 5‐HT precursor l‐tryptophan and the tryptophan hydroxylase co‐factor tetrahydrobiopterin (BH4). The presence of tonic autoinhibition under these conditions was revealed by the disinhibitory effect of a low concentration of the 5‐HT1A antagonist WAY 100635. Neurons showing an autoinhibitory response to l‐tryptophan were confirmed immunohistochemically to be serotonergic. Once conditions for tonic autoinhibition had been established in raphe slice, we were able to show that 5‐HT autoinhibition is critically regulated by the tryptophan hydroxylase‐activating kinases calcium/calmodulin protein kinase II (CaMKII) and protein kinase A (PKA). In addition, at physiological concentrations of l‐tryptophan, there was an augmentation of 5‐HT1A receptor‐mediated autoinhibition when the firing of 5‐HT cells activated with increasing concentrations of the α1 adrenoceptor agonist phenylephrine. Increased calcium influx at higher firing rates, by activating tryptophan hydroxylase via CaMKII and PKA, can work together with tryptophan to enhance negative feedback control of the output of the serotonergic system.
Anterior perirhinal cortex kindling produces long‐lasting effects on anxiety and object recognition memory
Authors: Hannesson D. K. , Howland J. G. , Pollock M. , Mohapel P. , Wallace A. E. , Corcoran M. E. 
Published: March 2005

AbstractTemporal lobe epilepsy (TLE) is frequently accompanied by memory impairments and, although their bases are unknown, most research has focused on the hippocampus. The present study investigated the importance of another medial temporal lobe structure, the perirhinal cortex (Prh), in changes in memory in TLE using kindling as a model. Rats were kindled twice daily with anterior Prh stimulation until three fully generalized seizures were evoked. Beginning 7 days later and on successive days, rats were tested in an elevated plus maze, a large circular open field, an open field object exploration task and a delayed‐match‐to‐place task in a water maze in order to assess anxiety‐related and exploratory behaviour, object recognition memory and spatial cognition. Kindling increased anxiety‐related behaviour in both the elevated plus and open field mazes and disrupted spontaneous object recognition but spared all other behaviours tested. These results are consistent with other findings indicating a greater role for the Prh in object memory and emotional behaviour than in spatial memory and contrast with the selective disruption of spatial memory produced by dorsal hippocampal kindling. The site‐selectivity of the behavioural disruptions produced by kindling indicates that such effects are probably mediated by changes particular to the site of seizure initiation rather than to changes in the characteristic circuitry activated by limbic seizure generalization. Further investigation of the behavioural effects of Prh kindling may be useful for studying the mechanisms of mnemonic and affective dysfunction associated with TLE and offer insights into bases for variability in such dysfunction across patients.
19‐Nortestosterone influences neural stem cell proliferation and neurogenesis in the rat brain
Authors: Brännvall Karin , Bogdanovic Nenad , Korhonen Laura , Lindholm Dan 
Published: March 2005

AbstractAbuse of androgenic anabolic steroids can affect brain function leading to behavioural changes. In this study, the effects of the testosterone analogue, 19‐nortestosterone, on rat neural stem cells was examined. The androgen receptor is expressed by cultured embryonic and adult neural stem cells, and is also present in the ventricular epithelium during development and in the adult brain in, among others, dentate gyrus. In neural stem cells stimulated with epidermal growth factor, nandrolone reduced cell proliferation, especially in adult ones. The decrease was abolished by flutamide, a receptor antagonist. Nandrolone also decreased the BrdU labelling of neural stem cells in the dentate gyrus, demonstrating an effect of the hormone on cell proliferation in vivo. The effect of nandrolone was observed with both female and male rats but it was more pronounced in pregnant rats, indicating an involvement of oestrogen in nandrolone action. Nandrolone also decreased the number of newly born neuronal cells in the dentate gyrus of male rats. The results show that nandrolone has important effects on the proliferation and differentiation of neural stem cells expressing the cognate androgen receptor. The data show that the use of nandrolone may severely affect the formation of neural stem cells and could therefore have long‐term negative consequences in the brain.