bluuebunny/crossref_metadata_2025_split huggingface dataset:
An NMR view of the unfolding process of rusticyanin: Structural elements that maintain the architecture of a β‐barrel metalloprotein
Authors: Alcaraz Luis A. , Jiménez Beatriz , Moratal José María , Donaire Antonio 
Published: June 2005

AbstractThe unfolding process of the blue copper protein rusticyanin (Rc) as well as its dynamic and D2O/H2O exchange properties in an incipient unfolded state have been studied by heteronuclear NMR spectroscopy. Titrations of apo, Cu(I), and Cu(II)Rc with guanidinium chloride (GdmCl) show that the copper ion stabilizes the folded species and remains bound in the completely unfolded state. The oxidized state of the copper ion is more efficient than the reduced form in this respect. The long loop of Rc (where the first ligand of the copper ion is located) is one of the most mobile domains of the protein. This region has no defined secondary structure elements and is prone to exchange its amide protons. In contrast, the last loop (including a short α‐helix) and the last β‐strand (where the other three ligands of the metal ion are located) form the most rigid domain of the protein. The results taken as a whole suggest that the first ligand detaches from the metal ion when the protein unfolds, while the other three ligands remain bound to it. The implications of these findings for the biological folding process of Rc are also discussed.
Solution structure of APETx2, a specific peptide inhibitor of ASIC3 proton‐gated channels
Authors: Chagot Benjamin , Escoubas Pierre , Diochot Sylvie , Bernard Cédric , Lazdunski Michel , Darbon Hervé 
Published: June 2005

AbstractAcid‐sensing ion channels (ASIC) are proton‐gated sodium channels that have been implicated in pain transduction associated with acidosis in inflamed or ischemic tissues. APETx2, a peptide toxin effector of ASIC3, has been purified from an extract of the sea anemone Anthopleura elegantissima. APETx2 is a 42‐amino‐acid peptide cross‐linked by three disulfide bridges. Its three‐dimensional structure, as determined by conventional two‐dimensional 1H‐NMR, consists of a compact disulfide‐bonded core composed of a four‐stranded β‐sheet. It belongs to the disulfide‐rich all‐β structural family encompassing peptide toxins commonly found in animal venoms. The structural characteristics of APETx2 are compared with that of PcTx1, another effector of ASIC channels but specific to the ASIC1a subtype and to APETx1, a toxin structurally related to APETx2, which targets the HERG potassium channel. Structural comparisons, coupled with the analysis of the electrostatic characteristics of these various ion channel effectors, led us to suggest a putative channel interaction surface for APETx2, encompassing its N terminus together with the type I‐β turn connecting β‐strands III and IV. This basic surface (R31 and R17) is also rich in aromatic residues (Y16, F15, Y32, and F33). An additional region made of the type II′‐β turn connecting β‐strands I and II could also play a role in the specificity observed for these different ion effectors.
Structure—function analysis of the α5 and the α13 helices of human glucokinase: Description of two novel activating mutations
Authors: Pedelini Leda , Garcia‐Gimeno Maria Adelaida , Marina Alberto , Gomez‐Zumaquero Juan M. , Rodriguez‐Bada Pablo , López‐Enriquez Soledad , Soriguer Federico C. , Cuesta‐Muñoz Antonio L. , Sanz Pascual 
Published: June 2005

AbstractIt was recently described that the α5 and the α13 helices of human pancreatic glucokinase play a major role in the allosteric regulation of the enzyme. In order to understand the structural importance of these helices, we have performed site‐directed mutagenesis to generate glucokinase derivatives with altered residues. We have analyzed the kinetic parameters of these mutated forms and compared them with wild‐type and previously defined activating mutations in these helices (A456V and Y214C). We found two new activating mutations, A460R and Y215A, which increase the affinity of the enzyme for glucose. Our results suggest that substitutions in the α5 or the α13 helices that favor the closed, active conformation of the enzyme, either by improving the interaction with surrounding residues or by improving the flexibility of the region defined by these two helices, enhance the affinity of the enzyme for glucose, and therefore its performance as a glucose phosphorylating enzyme.
Identification of karyopherin β as an immunogenic antigen of the malaria parasite using immune mice and human sera
Authors: Mohmmed Asif , Kishore Shivendra , Patra Kailash P. , Dasaradhi Palakodeti V. N. , Malhotra Pawan , Chauhan Virander S. 
Published: June 2005

SUMMARY A differential immunoscreening of the λgt11 Plasmodium falciparum genomic expression library was carried out using anti‐P. yoelii sera (convalescent‐phase mouse sera) and immune sera collected from healthy adults, to identify novel cross‐reactive and possibly protective antigens of the parasite. One clone, with an insert size of 1132 bp that reacted strongly with both the sera was selected. The insert was found to be a part of the P. falciparum karyopherin β (PfKβ) homologue. RT‐PCR and Northern blot analysis confirmed the expression of PfKβ in the blood stages of the parasite. The ∼110 kDa protein was localized in the cytoplasm at the ring and trophozoite, and in the parasitophorous vacuole at the schizont stage. Two large fragments of PfKβ representing the N‐ and C‐terminal halves were expressed in E. coli. The recombinant proteins were highly immunogenic in mice, and also found to be the target for immune response in natural infections of Plasmodium spp. Anti‐sera against the protein showed a low level of anti‐parasitic activity. Immunization with recombinant PfKβ fragments was only partially protective against a heterologous challenge infection in mice. Our results show that the parasite releases a highly immunogenic, cytoplasmic protein into the host which may not contribute to the development of protective immunity.
Maternal gestures with 20‐month‐old infants in two contexts
Authors: O'Neill Maria , Bard Kim A. , Linnell Maggie , Fluck Michael 
Published: June 2005

Abstract Speech directed towards young children (‘motherese’) is subject to consistent systematic modifications. Recent research suggests that gesture directed towards young children is similarly modified (gesturese). It has been suggested that gesturese supports speech, therefore scaffolding communicative development (the facilitative interactional theory). Alternatively, maternal gestural modification may be a consequence of the semantic simplicity of interaction with infants (the interactional artefact theory). The gesture patterns of 12 English mothers were observed with their 20‐month‐old infants while engaged in two tasks, free play and a counting task, designed to differentially tap into scaffolding. Gestures accounted for 29% of total maternal communicative behaviour. English mothers employed mainly concrete deictic gestures (e.g. pointing) that supported speech by disambiguating and emphasizing the verbal utterance. Maternal gesture rate and informational gesture–speech relationship were consistent across tasks, supporting the interactional artefact theory. This distinctive pattern of gesture use for the English mothers was similar to that reported for American and Italian mothers, providing support for universality. Child‐directed gestures are not redundant in relation to child‐directed speech but rather both are used by mothers to support their communicative acts with infants.
Selectively increasing inducible heat shock protein 70 via TAT‐protein transduction protects neurons from nitrosative stress and excitotoxicity
Authors: Lai Yichen , Du Lina , Dunsmore Katherine E. , Jenkins Larry W. , Wong Hector R. , Clark Robert S. B. 
Published: June 2005

AbstractInduction of heat shock protein 70 (Hsp70) via sublethal stress protects neurons from subsequent lethal injuries. Here we show that specific and efficient intracellular transduction of Hsp70 can be achieved utilizing an 11 amino acid leading sequence from human immunodeficiency virus (TAT‐Hsp70) in primary neuronal cultures. Western blot and immunohistochemistry demonstrated intracellular accumulation of Hsp70 in insoluble protein fractions and mitochondrial compartments. We then examined the effects of Hsp70 overexpression using TAT‐Hsp70 in models of nitrosative and excitotoxic neuronal death in vitro. Neurons were pre‐incubated with 300 nm TAT‐Hsp 70 overnight, then exposed to either peroxynitrite (ONOO–) or glutamate. TAT‐Hsp70 maintained cellular respiration, inhibited extracellular lactate dehydrogenase release, and/or reduced cell death assessed by flow cytometry vs. vehicle, wild‐type Hsp70, and TAT‐β‐galactosidase controls. Hsp70 transduction using a TAT fusion protein is an effective method to selectively increase Hsp70 in neurons and is sufficient to provide neuroprotection from nitrosative stress and excitotoxicity. Further study is needed to confirm whether TAT‐Hsp70 is protective in in vivo models of brain injury.
Classification of Migraine and Tension Headache from a Survey of 10,000 Headache Diaries
Authors: Cohen Michael J. , McArthur David L. 
Published: June 2005

SYNOPSISDescriptions of migraine and muscle tension headaches have been based primarily on retrospective medical histories. To obtain a more accurate picture of symptoms patients use to classify these headaches, a sample of 10,000 headaches was gathered from daily diaries. Patients experiencing both migraine and tension headaches are able to differentiate these disorders consistently, using moderate ratings of intensity, low ratings of disability, and short length for tension headaches, and ratings of relatively high intensity and disability, moderately long duration, and occasional gastrointestinal upset for migraine headaches. These configurations confirm the general view obtained from medical histories.
Fenoprofen in the Prophylaxis of Migraine: A Double—Blind, Placebo Controlled Study
Authors: Diamond Seymour , Solomon Glen D. , Freitag Frederick G. , Mehta Nilesh D. 
Published: June 2005

SYNOPSISWe undertook a double‐blind, placebo controlled study to determine the effectiveness of fenoprofen calcium in the prophylaxis of migraine. One hundred and ten patients were treated with fenoprofen 200 mg. TID (35 patients), fenoprofen 600 mg. TID (39 patients), or matching placebo (36 patients), for 12 weeks, following a four week placebo baseline phase. Migraine frequency, severity, duration, and need for relief medication were recorded using headache diaries. Greater than 50% improvement in headache unit index was observed in 22% of patients on fenoprofen 200 mg. TID (p<0.05) and 36% of patients on fenoprofen 600 mg. TID (p<0.005). Fenoprofen 600 mg. resulted in 50% or greater reduction in corrected headache unit index in 59% of patients (p<0.005) and relief medication index in 55% (p<0.001), Gastrointestinal side effects were reported in 13.5% of patients, and fatigue was noted in 4% of patients treated with fenoprofen 600 mg. TID. We conclude that fenoprofen is safe and effective in the prophylaxis of migraine.
Exercise‐Induced Migraine Prodrome Symptoms
Authors: Thompson J. Kevin 
Published: June 2005

SYNOPSISFollowing consumption of a somewhat more than usual amount of coffee, and on a background of only scant food intake that day, a physically‐fit 31 year old male engaged in unusually strenuous running. About an hour after cessation of exercise, he developed, for the first time in his life, symptoms consistent with a migraine prodrome (as a researcher in migraine, the subject was familiar with the symptoms of migraine, though he himself was not a migraine sufferer). No head pain followed. The roles of caffeine, hypoglycemia, and exercise, alone and in combination, require investigation in the evaluation of other cases of exercise‐induced migraine. Also, the occurrence of exercise‐induced prodromes, without headache, may not be correctly interpreted by some subjects unfamiliar with the multiple potential manifestations of migraine.
Focal Headache During Balloon Inflation in the Vertebral and Basilar Arteries
Authors: Nichols Fenwick T. , Mawad Michel , Mohr J.P. , Hilal Sadek , Adams Robert J. 
Published: June 2005

SYNOPSISBackground and Purpose: Headache may be seen in acute cerebrovascular disease. The significance of localized headache in association with vertebrobasilar disease has not been recognized.Summary of Report: We describe a patient with a cerebellar arteriovenous malformation who underwent intravascular balloon occlusion of the vertebral and basilar artery. He developed reproducible patterns of referred pain with balloon inflation at specific sites.Conclusions: Well localized head pain in the setting of acute stroke should alert physicians to the possibility of localized arterial injury. The pattern seen in this patient has been documented in experimental situations, and should be of use in the setting of acute stroke.
Vestibulo‐Ocular Reflex in Migraine Patients: The Effect of Sodium Valproate
Authors: Gordon C.R. , Kuritzky A. , Doweck I. , Spitzer O. , Shupak A. , Hering R. 
Published: June 2005

SYNOPSISWe studied vestibulo‐ocular reflex measurements in a group of 12 patients suffering from migraine without aura and evaluated the effect of sodium valproate given as prophylactic migraine therapy. The study was randomized, double blind and placebo controlled, with a crossover design. The horizontal vestibulo‐ocular reflex was evaluated by the Sinusoidal Harmonic Acceleration test at 0.01, 0.02, 0.04, 0.08end 0.16 Hz using a computerized rotatory chair system. No abnormalities were found for the vestibulo‐ocular reflex gain, phase and asymmetry at each of the frequencies examined during the placebotreatment. These normal vestibulo‐ocular reflex measurements contrasted with the repeated complaints of dizziness, vertigo and unsteadiness reported by 7 patients (58%). Sodium valproate affected neither vestibulo‐ocular responses nor vestibular complaints but was effective in reducing migraine attacks in 8 of the 12 patients. These results demonstrate that the low frequency vestibulo‐ocular reflex measurements are normal in patients suffering from migraine without aura.
The Effects of Streptomycin/Lidocaine Block on Trigeminal Neuralgia: A Double Blind Crossover Placebo Controlled Study
Authors: Bittar Geber T. , Graff‐Radford Steven B. 
Published: June 2005

SYNOPSISThis study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double‐blind placebo controlled randomized design was used. After the clinical assessment subjects were randomly assigned to receive either 1 g of streptomycin with 3 ml 2% lidocaine, or 3 ml lidocaine alone. The injections were performed adjacent to the branches that served the painful site. These were intraoral injections, more specifically infraorbital and inferior alveolar blocks. Patients received five blocks of either streptomycin/lidocaine or lidocaine alone for a period of five consecutive weeks. On the sixth week they were crossed over. Measures of pain intensity and pain frequency were used to assess treatment outcome. Patients also recorded their side‐effects. Repeated measures analysis of variance was used to compare the treatment outcomes between the active and placebo groups. There was no statistically significant differences in the treatment outcomes regarding frequency and intensity of pain attacks. The sensory function of the treated nerves was also not affected. Side effects including facial swelling and pain were a common finding in the patients receiving streptomycin. This study demostrated no beneficial effects of streptomycin blockade for idiopathic and traumatic trigeminal neuralgia.
Disruption of Cortical Development as a Consequence of Repetitive Pilocarpine‐induced Status Epilepticus in Rats
Authors: Da Silva Alexandre Valotta , Regondi Maria Cristina , Cavalheiro Esper Abrão , Spreafico Roberto 
Published: June 2005

Summary:  Purpose: The aim of the present study was to observe possible cortical abnormalities after repetitive pilocarpine‐induced status epilepticus (SE) in rats during development. Methods: Wistar rats received intraperitoneal injection of pilocarpine hydrochloride 2% (380 mg/kg) at P7, P8, and P9. All experimental rats displayed SE after pilocarpine injections. Rats were killed at P10 and P35, and immunocytochemistry procedures were performed on 50‐μm vibratome sections, by using antibodies against nonphosphorylated neurofilament (SMI‐311), parvalbumin (PV), calbindin (CB), calretinin (CR), and glutamate decarboxylase (GAD‐65). Selected sections were used for the TUNEL method and double‐labeling experiments, with different mixtures of the same markers. Results: The major findings of the present work were (a) altered intracortical circuitry development; (b) anticipation of PV immunoreactivity in neocortical interneurons; (c) increased GAD‐65 immunoreactivity; and (d) reduced neocortical apoptotic process. Conclusions: From these results, we suggest that previously healthy brain, without genetic abnormalities, might develop an “acquired” disruption of cortical development whose evolution reproduces some characteristics of the childhood epilepsies associated with cognitive impairment.
Outcome of Status Epilepticus in Immature Rats Varies According to the Paraldehyde Treatment
Authors: Kubová Hana , Rejchrtová Jana , Redkozubova Olga , Mareš Pavel 
Published: June 2005

Summary: Purpose:To test effects of paraldehyde on behavioral outcome of status epilepticus (SE) in developing rats.Methods:Motor SE was induced by LiCl‐pilocarpine in rats on postnatal (P) day 12 or 25. Two hours after SE onset, animals were injected with a single dose of paraldehyde (0.07 and 0.3 ml/kg in the P12 group and 0.3 and 0.6 ml/kg in the P25 group). Effects on seizure severity and mortality were evaluated. Growth of animals and their motor abilities were monitored until the adulthood. Three months after SE, cognitive abilities were tested by using the Morris water maze.Results:Both tested doses of paraldehyde equally affected motor seizures. Convulsions continued until the paraldehyde administration, but then they quickly subsided in all groups. During the subsequent 24 h, occasional clonic seizures occurred in P25 animals treated with the lower dose of paraldehyde. Only hyperactivity and/or automatisms were observed in the other experimental groups. Mortality was not affected by the dosage of paraldehyde. The higher dosage of paraldehyde improved recovery after SE in both age groups. No difference was found in motor abilities between controls and SE animals, except shortening of time spent on the rod in the rotarod test in the P12 group. In P25 rats, treatment with a higher dosage of paraldehyde improved learning abilities compared with the lower dosage. In the P12 group, animals treated with the lower dosage exhibited slightly impaired learning compared with controls and animals receiving the higher dosage.Conclusions:Paraldehyde injected 2 h after SE onset modulates long‐term outcome in immature rats in a dose‐related manner.
Physiological Changes in Chronic Epileptic Rats Are Prominent in Superficial Layers of the Medial Entorhinal Area
Authors: Tolner Else A. , Kloosterman Fabian , Kalitzin Stiliyan N. , Da Silva Fernando H. Lopes , Gorter Jan A. 
Published: June 2005

Summary:  Purpose: We investigated whether the functional network properties of the medial entorhinal area (MEA) of the entorhinal cortex were altered in a rat model of chronic epilepsy that is characterized by extensive cell loss in MEA layer III. Methods: Responses were evoked in the entorhinal cortex by electrical stimulation of the subiculum in anesthetized chronic epileptic rats, 2–4 months after status epilepticus, induced by systemic kainate (KA) injections. Laminar field potentials were measured using a 16‐channel silicon probe that covered all six layers of the MEA; an estimate of the local transmembrane currents was made using current source density analysis. Results: Double‐pulse stimulation of the subiculum evoked responses in deep and superficial layers of the MEA in control and KA rats. A current sink in layer I and at the border of layer I and II that was induced by antidromic activation of MEA‐II, was much more prominent in KA rats with extensive neuronal loss in MEA‐III than in control rats or KA rats with minor MEA‐III loss. Furthermore, KA rats that displayed MEA‐III loss presented a series of oscillations induced by subicular stimulation in the β/γ‐frequency range (20–100 Hz), which were confined to superficial layers of MEA. These oscillations were never observed in control rats or KA rats with minor MEA‐III loss. Conclusions: These results indicate that the observed alterations in the superficial MEA responses to subiculum stimulation and the occurrence of β/γ‐oscillations are related phenomena, which are a consequence of altered and impaired inhibition within these MEA layers in chronic epileptic rats.
Changes in Cytochrome Oxidase in the Piriform Cortex after Status Epilepticus in Adult Rats
Authors: Otáhal Jakub , Suchomelová Lucie , Druga Rastislav , Kubová Hana 
Published: June 2005

Summary:  Purpose: The piriform cortex is involved in genesis and propagation of temporal lobe seizures. Degenerating neurons demonstrated by FluoroJade B staining are visible early after status epilepticus (SE) as well as after longer intervals. Furthermore, the piriform cortex is activated during an early phase of experimental temporal seizures, as described by magnetic resonance imaging (MRI) studies. It indicates that the early activity of the piriform cortex should be accompanied by increased adenosine triphosphate (ATP) production. Cytochrome oxidase activity in the brain may be used as an endogenous metabolic marker for neurons. The present research studied activity of the cytochrome oxidase separately in the rostral and caudal parts of the piriform cortex after lithium chloride–pilocarpine–induced SE in adult rats. Methods: SE was induced by a single dose of pilocarpine (40 mg/kg) in LiCl‐pretreated adult Wistar rats. Cytochrome oxidase activity was mapped by optical density on sections stained with histochemistry separately in the rostral and caudal parts of the piriform cortex. Results: Optical density of the rostral part of the piriform cortex remained nearly unchanged at both 1 week (0.284 ± 0.009 in SE group vs. 0.297 ± 0.005 in controls) and 3 months (0.318 ± 0.007 in SE group vs. 0.333 ± 0.004 in controls) after SE intervals. The caudal part of the piriform cortex showed a decrease of optical density in both groups at 1 week (0.265 ± 0.007 in SE group vs. 0.285 ± 0.009 in controls) and 3 months after SE (0.292 ± 0.006 in SE animals vs. 0.310 ± 0.003 in controls), respectively. Nissl‐stained sections demonstrated a marked neuronal loss and gliosis and/or necrotic cavities through the caudal piriform cortex 1 week after SE. Conclusions: Our results demonstrated that damage of the piriform cortex is not homogeneous and thus that its parts are differently involved in epileptic activity.