bluuebunny/crossref_metadata_2025_split huggingface dataset:
Victor Horsley's Contribution to Jacksonian Epileptology
Authors: Eadie Mervyn J. 
Published: November 2005

Summary:  Purpose: To describe Victor Horsley's contribution to John Hughlings Jackson's understanding of the mechanisms involved in the generalization of convulsive epileptic seizures. Methods: I reviewed Horsley's writings and other relevant late 19th century medical literature. Results: Horsley's combination of strategically sited surgical lesions and cerebral cortex stimulation studies in experimental animals showed that, contrary to Hughlings Jackson's earlier belief, epileptic activity arising in one cerebral hemisphere had to spread to the contralateral hemisphere before bilateral convulsing could occur. Conclusions: On the basis of well‐designed experiments, Horsley made a major contribution to the understanding of epileptic seizure propagation mechanisms.
Ipsilateral Head Deviation in Frontal Lobe Seizures
Authors: Rheims Sylvain , Demarquay Genevieve , Isnard Jean , Guenot Marc , Fischer Catherine , Sindou Marc , Mauguiere François , Ryvlin Philippe 
Published: November 2005

Summary:  Purpose: The lateralizing value of ictal head deviation (HD) in frontal lobe epilepsy (FLE) is a matter of debate. Although FLE is typically associated with tonic or clonic HD contralateral to seizure onset, ipsilateral HD has been noted in numerous reports. Whether both types of HD can be distinguished according to their clinical patterns has not yet been specifically investigated. Methods: We studied the clinical pattern and time of occurrence of HD of 129 seizures in 13 consecutive patients, who underwent successful surgery for FLE, including 12 investigated with an intracerebral stereotactic EEG procedure. Results: Ictal HD was ipsilateral to the epileptogenic zone (EZ) in four (30%) patients and 27 (20.9%) seizures and contralateral in five (38%) patients and 15 (11.6%) seizures. Ipsilateral HD was rarely tonic and never associated with clonic manifestation. Contralateral HD was always tonic, unnatural, and associated with hemifacial clonic movements in 86% of seizures. Ipsilateral HD occurred earlier than contralateral HD (p < 0.03), with a mean delay of 1 ± 2 s after the first detectable ictal sign, as compared with a delay of 17 ± 11 s for contralateral HD. Moreover, ipsilateral HD always occurred before contralateral HD when both signs coexisted in the same seizure. Our patients with ipsilateral HD demonstrated either an anterior or dorsolateral frontal EZ. Conclusions: Ipsilateral HD is a common ictal sign during FLE and can be distinguished from contralateral HD by its time of occurrence at or immediately after seizure onset and its lacking association with clonic movements.
Unilateral Intracarotid Amobarbital Procedure for Language Lateralization
Authors: Wellmer Jörg , Fernández Guillen , Linke Detlef B. , Urbach Horst , Elger Christian E. , Kurthen Martin 
Published: November 2005

Summary:  Purpose: The determination of language dominance as part of the presurgical workup of patients with pharmacoresistant epilepsies has experienced fundamental changes. With the introduction of noninvasive functional magnetic resonance imaging (fMRI), the number of patients receiving intracarotid amobarbital procedures (IAPs) for assessment of language dominance has decreased considerably. However, recent studies show that because of methodologic limitations of fMRI, IAP remains an important tool for language lateralization. The current study examines whether unilateral instead of bilateral IAP is an adequate way to apply IAP with reduced invasiveness. Methods: We retrospectively examine the predictive value of unilateral IAP for the results of bilateral IAP based on a sample of 75 patients with various types of language dominance. Target parameters are the prediction of the language‐dominant hemisphere and the identification of patients with atypical language dominance. For language assessment based on unilateral IAP, we introduce the measure hemispheric language capacity (HLC). Results: Unilateral IAP performed on the side of intended surgery quantifies language capacity contralateral to the intended surgery. It detects atypical (bilateral or right) language dominance in the majority of patients. Experience with a separate series of 107 patients requiring presurgical language lateralization shows that in >80%, bilateral IAPs are redundant. Conclusions: Unilateral IAP is principally sufficient for language lateralization in the presurgical evaluation of patients with pharmacoresistant epilepsies. Necessity of bilateral IAP is restricted to few indications (e.g., callosotomy). In times of noninvasive language lateralization, we propose unilateral IAP as the method of choice for the verification of doubtful (bilateral) fMRI activation patterns.
Methyl cellulose gel obstructed bone formation by GBR: an experimental study in rats
Authors: Lioubavina‐Hack Natalia , Karring Thorkild , Lynch Samuel E. , Lindhe Jan 
Published: November 2005

AbstractAim: To evaluate whether bone formation under Teflon capsules may be enhanced by concomitant implantation of recombinant human platelet‐derived growth factor‐BB/insulin‐like growth factor‐I (rhPDGF‐BB/IGF‐I) incorporated into a methyl cellulose gel.Materials and Methods: Fifty‐five male 6‐month‐old albino rats of the Wistar strain were used in the study. The lateral aspect of the mandibular ramus was exposed on both sides of the jaw. In 70 sites, the periosteum was removed from the ramus, leaving the bone denuded, while in 35 sites, it was preserved. On 10 non‐periosteal (P−) sites and five periosteal (P+) sites, an empty rigid teflon capsule (d=7 mm), serving as control, was placed on the ramus. In the 40 test animals, the capsule placed on the one side of the jaw was filled at random with one of three different concentrations (1200, 600, 150 μg/ml) of rhPDGF‐BB/IGF‐I gel. The capsules placed on the contralateral side of the jaw contained a placebo methyl cellulose gel. Each growth factor group, defined according to the gel concentration, and the placebo group contained 10 capsules placed on the P− side and five capsules placed on the P+ side. Two months after surgery, all animals were sacrificed.Results: Histologic analysis revealed that in the non‐filled control capsules, the amount of new bone including the bone marrow was 29.9% and 39.7% of the capsule area on the P− and P+ sides, respectively. In the test capsules with the growth factor gel and placed on the P−sides, the amounts of new bone ranged from 5.6% to 6.3%, which were similar (p>0.05) to that formed in the capsules filled with the methyl cellulose gel (5.5%). New bone formation was larger in the capsules on the P+ sides than in those on the P− sides but was similar in the capsules with different growth factor concentrations (range 17.9–19.6%) and in those with placebo gel (21.0%). In all groups, the carrier gel was poorly absorbed and occupied most of the capsules.Conclusion: Local application of a methyl cellulose gel obstructed bone formation under Teflon capsules placed adjacent to uninjured cortical bone in the mandibular ramus of rats. These data suggest that another material should be utilized to deliver growth factors under Teflon membranes for guided bone regeneration.
Nicotine inhibits human gingival fibroblast migration via modulation of Rac signalling pathways
Authors: Fang Yiyu , Svoboda Kathy K. H. 
Published: November 2005

AbstractAim:Cigarette smoking is a risk factor in the development of periodontal diseases. In addition, a delayed healing process has been shown in smokers compared with non‐smokers after periodontal treatment. Cell migration is a key process of wound healing and it is highly regulated by a variety of signalling pathways. The small G protein, Rac, is necessary for cell migration. Our aim was to determine if nicotine disrupted Rac and its downstream signalling proteins, p21‐activated kinase 1/2 (PAK1/2), and p44/42 mitogen‐activated protein kinase (MAPK) (extracellular regulated kinase 1/2).Material and Methods:Primary human fibroblasts from healthy gingival tissues were cultured and grown to confluence. Cells were serum starved for 24 h, and then treated with nicotine (0 or 0.5 μM) prior to in vitro wounding. Cell migration was analysed in live cell assays following in vitro wounds. Rac activity, phosphorylation levels of PAK1/2, and p44/42 MAPK were assessed in cultures treated with or without nicotine after multiple wounds.Results:Nicotine decreased cell migration rates by 50% compared with controls. In addition, nicotine altered the activation patterns of Rac and PAK 1/2 and up‐regulated p44/42 MAPK.Conclusion:Decreased cell migration in periodontal wounds exposed to nicotine may be mediated through the Rac and PAK1/2 signalling pathways.
Sonic‐powered toothbrushes and reversal of experimental gingivitis
Authors: Versteeg P. A. , Timmerman M. F. , Rosema N. A. M. , Warren P. R. , Van der Velden U. , Van der Weijden G. A. 
Published: November 2005

AbstractObjective: To compare two sonic toothbrushes in relation to the reversal of experimental gingivitis.Materials and Methods: Subjects refrained from brushing mandibular teeth for 21 days. During a 4‐week treatment phase, the right or left side of the mouth was brushed with either the Sonic Complete (SC) or Sonicare Elite (SE) toothbrush as randomly allocated. Plaque and gingivitis were assessed on day 0, after 21 days of no oral hygiene and after 1, 2 and 4 weeks of brushing twice daily.Results: Thirty‐four subjects provided evaluable data. The experimentally induced gingivitis (EIG) resulted in higher bleeding and plaque scores compared with day 0. The mean plaque scores at day 21 changed from 3.09 to 1.30 for the SC, and from 3.02 to 1.21 for the SE. At the end of the treatment period, there was no significant difference between the two brushes. The mean bleeding scores changed from 1.87 (day 21) to 0.97 for the SC, and from 1.83 to 0.92 for the SE. For the assessments at 1, 2 and 4 weeks post‐EIG, both brushes showed a significant decrease in bleeding scores. There were no statistically significant differences between brushes.
Serum antibodies to periodontal pathogens and markers of systemic inflammation
Authors: Dye Bruce A. , Choudhary Khalid , Shea Steven , Papapanou Panos N. 
Published: November 2005

AbstractAim: We examined the relationship between serum antibodies against Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, and plasma fibrinogen and serum C‐reactive protein (CRP) in a nationally representative sample.Methods: Data on 2973 participants aged 40 years and older from the third National Health and Nutrition Examination Survey, second phase (1991–1994) were used. Three logistic regression models adjusted for gender, race, educational attainment, diabetes, cigarette smoking, body mass index (BMI), and other inflammatory conditions were constructed, based on three different assumptions: (A) no access to dental/periodontal data; (B) knowledge of number of teeth present but not of clinical periodontal status; and (C) knowledge of both dental and clinical periodontal status.Results: High fibrinogen (>400 mg/dl) was unrelated to P. gingivalis and A. actinomycetemcomitans antibodies in all models. High CRP (>0.4 mg/dl) was related to high antibody levels to P. gingivalis in models A [odds ratios (OR) 1.63, 95% confidence intervals (CI) 1.15–2.32], B (OR 1.69, 95% CI 1.18–2.41), and C (OR 1.58, 95% CI 1.12–2.23). In model C, high CRP was related to >30% extent of attachment loss of 3 mm (OR 1.58, 95% CI 1.19–2.08). Antibodies to A. actinomycetemcomitans were not associated with high CRP levels in any model.Conclusions: High serum titre to P. gingivalis and the presence of periodontal disease are independently related to high CRP levels.
The Activity Profile of the NhaD-Type Na
+
(Li
+
)/H
+
Antiporter from the Soda Lake Haloalkaliphile
Alkalimonas amylolytica
Is Adaptive for the Extreme Environment
Authors: Liu Jun , Xue Yanfen , Wang Quanhui , Wei Yi , Swartz Talia H. , Hicks David B. , Ito Masahiro , Ma Yanhe , Krulwich Terry A. 
Published: November 2005

ABSTRACT

In extreme alkaliphiles, Na
+
/H
+
antiporters play a central role in the Na
+
cycle that supports pH homeostasis, Na
+
resistance, solute uptake, and motility. Properties of individual antiporters have only been examined in extremely alkaliphilic soil
Bacillus
spp., whereas the most alkaline natural habitats usually couple high pH with high salinity. Here, studies were conducted on a Na
+
(Li
+
)/H
+
antiporter, NhaD, from the soda lake haloalkaliphile
Alkalimonas amylolytica
. The activity profile of
A. amylolytica
NhaD at different pH values and Na
+
concentrations reflects its unique natural habitat. In membrane vesicles from antiporter-deficient
Escherichia coli
EP432 (Δ
nhaA
Δ
nhaB
), the pH optimum for NhaD-dependent Na
+
(Li
+
)/H
+
antiport was at least 9.5, the highest pH that could be tested; no activity was observed at pH ≤8.5. NhaD supported low Na
+
/H
+
antiport activity at pH 9.5 that was detectable over a range of Na
+
concentrations from 10 mM to at least 800 mM, with a 600 mM optimum. Although
A. amylolytica nhaD
was isolated by complementing the Li
+
sensitivity of the triple mutant
E. coli
strain KNabc (Δ
nhaA
Δ
nhaB
Δ
chaA
), sustained propagation of
nhaD
-bearing plasmids in this strain resulted in a glycine (Gly
327
)→serine mutation in a putative cytoplasmic loop of the mutant transporter. The altered activity profile of NhaD-G327S appears to be adaptive to the
E. coli
setting: a much higher activity than wild-type NhaD at Na
+
concentrations up to 200 mM but lower activity at 400 to 600 mM Na
+
, with a pH optimum and minimal pH for activity lower than those of wild-type NhaD.
High-Resolution Visualization ofPseudomonas aeruginosaPAO1 Biofilms by Freeze-Substitution Transmission Electron Microscopy
Authors: Hunter Ryan C. , Beveridge Terry J. 
Published: November 2005

ABSTRACTHigh-pressure freeze-substitution and transmission electron microscopy have been used for high-resolution imaging of the natural structure of a gram-negative biofilm. Unlike more conventional embedding techniques, this method confirms many of the observations seen by confocal microscopy but with finer structural detail. It further reveals that there is a structural complexity to biofilms at both the cellular and extracellular matrix levels that has not been seen before. Different domains of healthy and lysed cells exist randomly dispersed within a single biofilm as well as different structural organizations of exopolymers. Particulate matter is suspended within this network of fibers and appears to be an integral part of the exopolymeric substance (EPS). O-side chains extending from the outer membrane are integrated into EPS polymers so as to form a continuum. Together, the results support the concept of physical microenvironments within biofilms and show a complexity that was hitherto unknown.
Genetic Composition of theBacillus subtilisSOS System
Authors: Au Nora , Kuester-Schoeck Elke , Mandava Veena , Bothwell Laura E. , Canny Susan P. , Chachu Karen , Colavito Sierra A. , Fuller Shakierah N. , Groban Eli S. , Hensley Laura A. , O'Brien Theresa C. , Shah Amish , Tierney Jessica T. , Tomm Louise L. , O'Gara Thomas M. , Goranov Alexi I. , Grossman Alan D. , Lovett Charles M. 
Published: November 2005

ABSTRACTThe SOS response in bacteria includes a global transcriptional response to DNA damage. DNA damage is sensed by the highly conserved recombination protein RecA, which facilitates inactivation of the transcriptional repressor LexA. Inactivation of LexA causes induction (derepression) of genes of the LexA regulon, many of which are involved in DNA repair and survival after DNA damage. To identify potential RecA-LexA-regulated genes inBacillus subtilis, we searched the genome for putative LexA binding sites within 300 bp upstream of the start codons of all annotated open reading frames. We found 62 genes that could be regulated by putative LexA binding sites. Using mobility shift assays, we found that LexA binds specifically to DNA in the regulatory regions of 54 of these genes, which are organized in 34 putative operons. Using DNA microarray analyses, we found that 33 of the genes with LexA binding sites exhibit RecA-dependent induction by both mitomycin C and UV radiation. Among these 33 SOS genes, there are 22 distinct LexA binding sites preceding 18 putative operons. Alignment of the distinct LexA binding sites reveals an expanded consensus sequence for theB. subtilisoperator: 5′-CGAACATATGTTCG-3′. Although the number of genes controlled by RecA and LexA inB. subtilisis similar to that ofEscherichia coli, only eightB. subtilisRecA-dependent SOS genes have homologous counterparts inE. coli.
Molecular and Biochemical Characterization of the
xlnD
-Encoded 3-Hydroxybenzoate 6-Hydroxylase Involved in the Degradation of 2,5-Xylenol via the Gentisate Pathway in
Pseudomonas alcaligenes
NCIMB 9867
Authors: Gao Xiaoli , Tan Chew Ling , Yeo Chew Chieng , Poh Chit Laa 
Published: November 2005

ABSTRACT

The
xlnD
gene from
Pseudomonas alcaligenes
NCIMB 9867 (strain P25X) was shown to encode 3-hydroxybenzoate 6-hydroxylase I, the enzyme that catalyzes the NADH-dependent conversion of 3-hydroxybenzoate to gentisate. Active recombinant XlnD was purified as a hexahistidine fusion protein from
Escherichia coli
, had an estimated molecular mass of 130 kDa, and is probably a trimeric protein with a subunit mass of 43 kDa. This is in contrast to the monomeric nature of the few 3-hydroxybenzoate 6-hydroxylases that have been characterized thus far. Like other 3-hydroxybenzoate 6-hydroxylases, XlnD could utilize either NADH or NADPH as the electron donor. P25X harbors a second 3-hydroxybenzoate 6-hydroxylase II that was strictly inducible by specific aromatic substrates. However, the degradation of 2,5-xylenol and 3,5-xylenol in strain P25X was found to be dependent on the
xlnD
-encoded 6-hydroxylase I and not the second, strictly inducible 6-hydroxylase II.
In Vitro Analysis of Protein-Operator Interactions of the NikR and Fur Metal-Responsive Regulators of Coregulated Genes inHelicobacter pylori
Authors: Delany Isabel , Ieva Raffaele , Soragni Alice , Hilleringmann Markus , Rappuoli Rino , Scarlato Vincenzo 
Published: November 2005

ABSTRACTTwo important metal-responsive regulators, NikR and Fur, are involved in nickel and iron homeostasis and controlling gene expression inHelicobacter pylori.To date, they have been implicated in the regulation of sets of overlapping genes. We have attempted here dissection of the molecular mechanisms involved in transcriptional regulation of the NikR and Fur proteins, and we investigated protein-promoter interactions of the regulators with known target genes. We show thatH. pyloriNikR is a tetrameric protein and, through DNase I footprinting analysis, we have identified operators for NikR to which it binds with different affinities in a metal-responsive way. Mapping of the NikR binding site upstream of the urease promoter established a direct role for NikR as a positive regulator of transcription and, through scanning mutagenesis of this binding site, we have determined two subsites that are important for the binding of the protein to its target sequence. Furthermore, by alignment of the operators for NikR, we have shown that theH. pyloriprotein recognizes a sequence that is distinct from its well-studied orthologue inEscherichia coli.Moreover, we show that NikR and Fur can bind independently at distinct operators and also compete for overlapping operators in some coregulated gene promoters, adding another dimension to the previous suggested link between iron and nickel regulation. Finally, the importance of an interconnection between metal-responsive gene networks for homeostasis is discussed.
Assembly and Function of a Spore Coat-Associated Transglutaminase of
Bacillus subtilis
Authors: Zilhão Rita , Isticato Rachele , Martins Lígia O. , Steil Leif , Völker Uwe , Ricca Ezio , Moran Charles P. , Henriques Adriano O. 
Published: November 2005

ABSTRACT

The assembly of a multiprotein coat around the
Bacillus subtilis
spore confers resistance to lytic enzymes and noxious chemicals and ensures normal germination. Part of the coat is cross-linked and resistant to solubilization. The coat contains ε-(γ-glutamyl)lysyl cross-links, and the expression of the gene (
tgl
) for a spore-associated transglutaminase was shown before to be required for the cross-linking of coat protein GerQ. Here, we have investigated the assembly and function of Tgl. We found that Tgl associates, albeit at somewhat reduced levels, with the coats of mutants that are unable to assemble the outer coat (
cotE
), that are missing the inner coat and with a greatly altered outer coat (
gerE
), or that are lacking discernible inner and outer coat structures (
cotE gerE
double mutant). This suggests that Tgl is present at various levels within the coat lattice. The assembly of Tgl occurs independently of its own activity, as a single amino acid substitution of a cysteine to an alanine (C116A) at the active site of Tgl does not affect its accumulation or assembly. However, like a
tgl
insertional mutation, the
tglC116A
allele causes increased extractability of polypeptides of about 40, 28, and 16 kDa in addition to GerQ (20 kDa) and affects the structural integrity of the coat. We show that most Tgl is assembled onto the spore surface soon after its synthesis in the mother cell under σ
K
control but that the complete insolubilization of at least two of the Tgl-controlled polypeptides occurs several hours later. We also show that a multicopy allele of
tgl
causes increased assembly of Tgl and affects the assembly, structure, and functional properties of the coat.
Cell Division Defects inEscherichia coliDeficient in the Multidrug Efflux Transporter AcrEF-TolC
Authors: Lau Sze Yi , Zgurskaya Helen I. 
Published: November 2005

ABSTRACTTheEscherichia colichromosome contains several operons encoding confirmed and predicted multidrug transporters. Among these transporters only the inactivation of components of the AcrAB-TolC complex leads to substantial changes in susceptibility to multiple drugs. This observation prompted a conclusion that other transporters are silent or expressed at levels insufficient to contribute to multidrug resistance phenotype. We found that increased expression of AcrA, the periplasmic membrane fusion protein, is toxic only in cells lacking the multidrug efflux transporter AcrEF. AcrEF-deficient cells with increased expression of AcrA have a severe cell division defect that results in cell filamentation (>50 μm). Similar defects were obtained in cells lacking the outer membrane channel TolC, which acts with AcrEF, suggesting that cell filamentation is caused by the loss of AcrEF function. Green fluorescent protein-AcrA fusion studies showed that in normal and filamentous cells AcrA is associated with membranes in a confined manner and that this localization is not affected by the lack of AcrEF. Similarly, the structure and composition of membranes were normal in filamentous cells. Fluorescence microscopy showed that the filamentous AcrEF-deficientE. colicells are defective in chromosome condensation and segregation. Our results suggest that theE. coliAcrEF transporter is expressed under standard laboratory conditions and plays an important role in the normal maintenance of cell division.