bluuebunny/crossref_metadata_2025_split huggingface dataset:
The VirE1VirE2 complex of Agrobacterium tumefaciens interacts with single‐stranded DNA and forms channels
Authors: Duckely Myriam , Oomen Clasien , Axthelm Fabian , Van Gelder Patrick , Waksman Gabriel , Engel Andreas 
Published: October 2005

SummaryThe VirE2 protein is crucial for the transfer of single‐stranded DNA (ssDNA) from Agrobacterium tumefaciens to the nucleus of the plant host cell because of its ssDNA binding activity, assistance in nuclear import and putative ssDNA channel activity. The native form of VirE2 in Agrobacterium's cytoplasm is in complex with its specific chaperone, VirE1. Here, we describe the ability of the VirE1VirE2 complex to both bind ssDNA and form channels. The affinity of the VirE1VirE2 complex for ssDNA is slightly reduced compared with VirE2, but the kinetics of binding to ssDNA are unaffected by the presence of VirE1. Upon binding of VirE1VirE2 to ssDNA, similar helical structures to those reported for the VirE2–ssDNA complex were observed by electron microscopy. The VirE1VirE2 complex can release VirE1 once the VirE2–ssDNA complexes assembled. VirE2 exhibits a low affinity for small unilamellar vesicles composed of bacterial lipids and a high affinity for lipid vesicles containing sterols and sphingolipids, typical components of animal and plant membranes. In contrast, the VirE1VirE2 complex associated similarly with all kind of lipids. Finally, black lipid membrane experiments revealed the ability of the VirE1VirE2 complex to form channels. However, the majority of the channels displayed a conductance that was a third of the conductance of VirE2 channels. Our results demonstrate that the binding of VirE1 to VirE2 does not inhibit VirE2 functions and that the effector–chaperone complex is multifunctional.
The flagellar hierarchy of Rhodobacter sphaeroides is controlled by the concerted action of two enhancer‐binding proteins
Authors: Poggio Sebastian , Osorio Aurora , Dreyfus Georges , Camarena Laura 
Published: October 2005

SummaryThe expression of the bacterial flagellar genes follows a hierarchical pattern. In Rhodobacter sphaeroides the flagellar genes encoding the hook and basal body proteins are expressed from σ54‐dependent promoters. This type of promoters is always regulated by transcriptional activators that belong to the family of the enhancer‐binding proteins (EBPs). We searched for possible EBPs in the genome of R. sphaeroides and mutagenized two open reading frames (ORFs) (fleQ and fleT), which are in the vicinity of flagellar genes. The resulting mutants were non‐motile and could only be complemented by the wild‐type copy of the mutagenized gene. Transcriptional fusions showed that all the flagellar σ54‐dependent promoters with exception of fleTp, required both transcriptional activators for their expression. Interestingly, transcription of the fleT operon is only dependent on FleQ, and FleT has a negative effect. Both activators were capable of hydrolysing ATP, and were capable of promoting transcription from the flagellar promoters at some extent. Electrophoretic mobility shift assays suggest that only FleQ interacts with DNA whereas FleT improves binding of FleQ to DNA. A four‐tiered flagellar transcriptional hierarchy and a regulatory mechanism based on the intracellular concentration of both activators and differential enhancer affinities are proposed.
BapA, a large secreted protein required for biofilm formation and host colonization of Salmonella enterica serovar Enteritidis
Authors: Latasa Cristina , Roux Agnès , Toledo‐Arana Alejandro , Ghigo Jean‐Marc , Gamazo Carlos , Penadés José R. , Lasa Iñigo 
Published: October 2005

SummaryIn environmental settings, biofilms represent the common way of life of microorganisms. Salmonella enterica serovar Enteritidis, the most frequent cause of gastroenteritis in developed countries, produces a biofilm whose matrix is mainly composed of curli fimbriae and cellulose. In contrast to other bacterial biofilms, no proteinaceous compound has been reported to participate in the formation of this matrix. Here, we report the discovery of BapA, a large cell‐surface protein required for biofilm formation by S. Enteritidis. Deletion of bapA caused the loss of the capacity to form a biofilm whereas the overexpression of a chromosomal copy of bapA increased the biofilm biomass formation. We provide evidence that overproduction of curli fimbriae and not cellulose can compensate for the biofilm deficiency of a bapA mutant strain. BapA is secreted through a type I protein secretion system (BapBCD) situated downstream of the bapA gene and was found to be loosely associated with the cell surface. Experiments with mixed bacterial populations positive or negative for BapA showed that BapA minus cells are not recruited into the biofilm matrix. The expression of bapA is coordinated with that of genes encoding curli fimbriae and cellulose, through the action of csgD. Studies on the contribution of BapA to S. Enteritidis pathogenesis revealed that orally inoculated animals with a bapA‐deficient strain survived longer than those inoculated with the wild‐type strain. Also, a bapA mutant strain showed a significantly lower colonization rate at the intestinal cell barrier and consequently a decreased efficiency for organ invasion compared with the wild‐type strain. Taken together, these data demonstrate that BapA contributes both to biofilm formation and invasion through the regular Salmonella infection route.
Identification of a defective molecule derived from DNA‐A of the bipartite begomovirus of East African cassava mosaic virus
Authors: Ndunguru J. , Legg J. P. , Fofana I. B. F. , Aveling T. A. S. , Thompson G. , Fauquet C. M. 
Published: October 2005

Geminivirus defective interfering DNAs arise spontaneously in mechanically inoculated test plants, and have previously been found with DNA‐B of the bipartite cassava mosaic geminiviruses, but not DNA‐A. Reported here for the first time is the cloning and characterization of a naturally occurring truncated form of cassava mosaic geminivirus DNA‐A, which at 1525 nt is around half the expected full size. Sequence analysis has shown it to be a defective (df) form of East African cassava mosaic virus (EACMV) DNA‐A that has retained its cis elements essential for replication by the helper virus, and it has been termed df DNA‐A 15. Phylogenetic comparisons placed the df DNA‐A 15 molecule close to mild and severe isolates of EACMV‐UG2. Biolistic inoculation of Nicotiana benthamiana with infectious df DNA‐A 15 clone and East African cassava mosaic Cameroon virus (EACMCV) resulted in symptom amelioration as compared with EACMCV singly inoculated plants, and there was an accumulation of df DNA‐A 15 in systemically infected leaves. In addition, the level of EACMV DNA‐B accumulation was reduced in the coinoculated plants compared with those inoculated with EACMCV alone. PCR and sequence analysis confirmed the helper virus as EACMV.
Hormonally controlled expression of the Arabidopsis MAX4 shoot branching regulatory gene
Authors: Bainbridge Katherine , Sorefan Karim , Ward Sally , Leyser Ottoline 
Published: October 2005

SummaryThe Arabidopsis MORE AXILLARY BRANCHING 4 (MAX4) gene is required for the production of a long‐range, graft‐transmissible signal that inhibits shoot branching. Buds of max4 mutant plants are resistant to the inhibitory effects of apically applied auxin, indicating that MAX4 is required for auxin‐mediated bud inhibition. The RAMOSUS 1 (RMS1) and DECREASED APICAL DOMINANCE 1 (DAD1) genes of pea and petunia, respectively, are orthologous to MAX4 and function in a similar way. Here we show that, despite the similarities between these three genes, there are significant differences in the regulation of their expression. RMS1 is known to be upregulated by auxin in the shoot, suggesting a straightforward link between the RMS1‐dependent branch‐inhibiting signal and auxin, whereas we find that MAX4 is only upregulated by auxin in the root and hypocotyl, and this is not required for the inhibition of shoot branching. Furthermore, both RMS1 and DAD1 are subject to feedback regulation, for which there is no evidence for MAX4. Instead, overexpression studies and reciprocal grafting experiments demonstrate that the most functionally significant point of interaction between auxin and MAX4 is post‐transcriptional and indeed post‐synthesis of the MAX4‐dependent graft‐transmissible signal.
The association between HLA class II haplotype with Graves' disease in Thai population
Authors: Wongsurawat T. , Nakkuntod J. , Charoenwongse P. , Snabboon T. , Sridama V. , Hirankarn N. 
Published: October 2005

AbstractThe distribution of HLA‐DRB1, ‐DQA1 and ‐DQB1 alleles were analysed in 124 Graves' disease (GD) patients compared to 124 normal controls in order to identify the alleles/haplotypes associated with GD in Thai population. The DRB1*1602‐DQA1*0102‐DQB1*0502 haplotype was significantly increased in GD patients (P = 0.0209, OR = 2.55). DRB1*07‐DQA1*0201‐DQB1*0201 haplotype (P = 0.039, OR = 0.32) and HLA‐DRB1*12‐DQA1*0601‐DQB1*0301 haplotype (P = 0.0025, OR = 0.28) were significantly decreased in GD patients. Interestingly, a protective DRB1*07 allele in Thai population lacks an arginine at position 74 similar to DRB1*0311 (a protective allele in Caucasians). A significant association of DRB1*1602‐DQA1*0102‐DQB1*0502 and HLA‐DRB1*12‐DQA1*0601‐DQB1*0301 alleles and haplotypes with GD was recently reported in Korean but not in any Caucasian studies. Thus, DRB1*1602 allele and closely linked haplotype, DRB1*1602‐DQA1*0102‐DQB1*0502, might serve as a marker for genetic susceptibility to GD in Asian population.
Generation of the B*41 group of alleles as indicated by intron sequences†
Authors: Martínez‐Laso J. , Moscoso J. , Zamora J. , Gómez‐Casado E. , Arnaiz‐Villena A. 
Published: October 2005

AbstractThe generation of the B*41 alleles has been analysed using exon 1, intron 1, exon 2, intron 2 and exon 3 sequences. Results showed that B*4102 may have been generated as the first B*41 allele by a recombination mechanism between B*400102 and B*0801 or B*4201 involving intron 2. B*4101, B*4104 and B*4107 alleles could have been generated from B*4102 by a gene conversion event taking three different fragments from sequences belonging to intron 2/exon 3 of B*45, B*50 or B*49 alleles. B*4105 and B*4106 could be generated from B*4101 allele by point mutations, and B*4103 generation is unclear due to the lack of intron 2. The importance of introns in HLA‐B allele polymorphism generation is stressed.
Mechanisms of inhibition by fluoride of urease activities of cell suspensions and biofilms of Staphylococcus epidermidis, Streptococcus salivarius, Actinomyces naeslundii and of dental plaque
Authors: Barboza‐Silva E. , Castro A. C. D. , Marquis R. E. 
Published: October 2005

Background/aims:  Fluoride is known to be a potent inhibitor of bacterial ureases and can also act in the form of hydrofluoric acid as a transmembrane proton conductor to acidify the cytoplasm of intact cells with possible indirect, acid inhibition of urease. Our research objectives were to assess the inhibitory potencies of fluoride for three urease‐positive bacteria commonly found in the mouth and to determine the relative importance of direct and indirect inhibition of ureases for overall inhibition of intact cells or biofilms.Methods:  The experimental design involved intact bacteria in suspensions, mono‐organism biofilms, cell extracts, and dental plaque. Standard enzymatic assays for ammonia production from urea were used.Results:  We found that ureolysis by cells in suspensions or mono‐organism biofilms of Staphylococcus epidermidis, Streptococcus salivarius or Actinomyces naeslundii was inhibited by fluoride at plaque levels of 0.1–0.5 mm in a pH‐dependent manner. The results of experiments with the organic weak acids indomethacin and capric acid, which do not directly inhibit urease enzyme, indicated that weak‐acid effects leading to cytoplasmic acidification are also involved in fluoride inhibition. However, direct fluoride inhibition of urease appeared to be the major mechanism for reduction in ureolytic activity in acid environments. Results of experiments with freshly harvested supragingival dental plaque indicated responses to fluoride similar to those of S. salivarius with pH‐dependent fluoride inhibition and both direct and indirect inhibition of urease.Conclusion:  Fluoride can act to diminish alkali production from urea by oral bacteria through direct and indirect mechanisms.
Quantification and detection of bacteria from postoperative maxillary cyst by polymerase chain reaction
Authors: Yamaura M. , Sato T. , Echigo S. , Takahashi N. 
Published: October 2005

Background/aims:  Postoperative maxillary cyst (POMC) is known to occur as a delayed complication of radical maxillary sinus surgery, such as Caldwell‐Luc surgery. The cyst gradually expands with no symptoms over a period of years, and then occasionally causes swelling and pain in the buccal region and/or the mucogingival fold. It is probable that bacterial infection affects the progression of POMC symptoms. The aims of this study were to determine the bacterial density and to examine the presence of 20 oral bacteria in POMC fluids.Methods:  POMC fluids (4 purulent, 2 mucous and 4 serous) were sampled from 10 subjects (aged 43–77 years). Bacterial quantification and detection were performed by real‐time polymerase chain reaction (PCR) and nested PCR based on bacterial 16S rRNA genes, respectively.Results:  Bacterial DNA was detected in all samples and the average concentrations of bacterial DNA were 5.9 (purulent), 0.5 (mucous), and 0.7 (serous) ng/mg of sample. Twelve bacterial species, including anginosus streptococci, known to be associated with abscess formation, were detected in the purulent fluids, while two and five species were detected in the mucous and serous fluids, respectively.Conclusion:  Purulent fluids contained numerous bacteria of various types, thus suggesting that oral bacteria may cause symptoms such as pain in POMC with purulent fluids. Mucous and serous fluids also contained bacteria, although their numbers were small, thus suggesting an association between bacteria and progression of POMC.
Oral lactobacilli in chronic periodontitis and periodontal health: species composition and antimicrobial activity
Authors: Kõll‐Klais P. , Mändar R. , Leibur E. , Marcotte H. , Hammarström L. , Mikelsaar M. 
Published: October 2005

Background/aims:  Lactobacilli are known to play an important role in the maintenance of health by stimulating natural immunity and contributing to the balance of microflora. However, their role in chronic periodontitis is unclear. We aimed to identify oral lactobacilli in chronic periodontitis and periodontally healthy subjects, and to determine their antimicrobial activity against putative oral pathogens.Methods:  A total of 238 Lactobacillus isolates from the saliva and subgingival sites of 20 chronic periodontitis and 15 healthy subjects were collected. In all, 115 strains were identified using rapid amplified ribosomal DNA restriction analysis. Antimicrobial activity against Streptococcus mutans, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia was assessed.Results:  Lactobacilli belonging to 10 species were identified. The most prevalent strains in healthy persons were Lactobacillus gasseri and Lactobacillus fermentum and in chronic periodontitis patients, Lactobacillus plantarum. Obligately homofermentatives, particularly L. gasseri, were less prevalent in chronic periodontitis patients compared with healthy subjects (8% vs. 64% for L. gasseri, P < 0.01). Sixty‐nine percent of tested lactobacilli inhibited S. mutans, 88%A. actinomycetemcomitans, 82%P. gingivalis and 65%P. intermedia. The strongest antimicrobial activity was associated with Lactobacillus paracasei, L. plantarum, Lactobacillus rhamnosus, and Lactobacillus salivarius. The strains from periodontally healthy patients showed a lower antimicrobial activity against S. mutans than the strains from chronic periodontitis patients.Conclusion:  The composition of oral lactoflora in chronic periodontitis and healthy subjects differs, with a higher prevalence of homofermentative lactobacilli, particularly L. gasseri, in the latter group. Both homo‐ and heterofermentative oral lactobacilli suppress the growth of periodontal pathogens, but the antimicrobial properties are strain, species and origin specific.
Active and passive immunization against oral Candida albicans infection in a murine model
Authors: Farah C. S. , Ashman R. B. 
Published: October 2005

Background/aims:  Clinical and laboratory studies are consistent with a major role for cell‐mediated immunity in recovery from oral infection with Candida albicans, but the role of humoral immunity remains controversial. The purpose of this study was to establish the relative contributions of cellular and humoral immunity to protection against oral candidiasis in a murine model, and to determine whether host responses could be enhanced by different immunization strategies.Results:  Active oral immunization was protective in BALB/c and CBA/CaH mice, reducing both fungal burden and duration of infection after secondary challenge, whereas systemic immunization failed to protect against subsequent oral challenge. Candida‐specific IgM was the predominant antibody detected in serum following both primary and secondary oral challenge; however, Candida‐specific salivary IgA was not detectable. Immunization by passive transfer of either lymphocytes or immune serum did not confer any significant protection against oral infection in either susceptible or resistant mouse strain.Conclusion:  The data demonstrate a possible role for mucosa‐associated immunity following active immunization by the oral route, most likely exerted by local T lymphocytes resident in the oral mucosa, but there was no evidence to support a role for humoral immunity in protection against oral candidiasis.
Identifying and improving non‐adherence in bipolar disorders
Authors: Colom F , Vieta E , Tacchi MJ , Sánchez‐Moreno J , Scott J 
Published: October 2005

Objectives:  To review the definition of non‐adherence, its clinical and economic impact and identify its role and impact in clinical practice.Methods:  A selective review of the literature as conducted of articles and literature known to the authors.Results:  There is a paucity of studies examining specifically treatment non‐adherence and its consequences in bipolar disorder. Few studies have systematically examined ways in which treatment adherence can impact treatment and improve outcome.Conclusion:  Non‐adherence is common in the management of bipolar disorder. Clinicians and Researchers alike need to remain alert and be aware of issues related to non‐adherence – in particular suicide. Like other course‐modifiers non‐adherence has to be considered, sought and addressed, and this is perhaps best done by including psychoeducation in routine clinical care.
Newer treatment studies for bipolar depression
Authors: Gao Keming , Calabrese Joseph R 
Published: October 2005

Objective:  Depressive symptoms of bipolar disorder have more negative impact on a patient's life than manic symptoms. This review focused on the emerging efficacy data for treatments in bipolar depression.Methods:  English‐language literature cited in Medline was searched with terms bipolar depression, clinical trial, and trial. Randomized, placebo‐controlled trials of newer studies with older agents and all studies with newer or novel agents were prioritized. Open‐label studies of novel agents presented at major scientific meetings were also included.Results:  Olanzapine, olanzapine–fluoxetine combination (OFC), and quetiapine were superior to placebo in the acute treatment of bipolar depression. Lamotrigine only significantly reduced core symptoms of depression compared with placebo. Pramipexole, a dopamine D2/D3 receptor agonist and omega‐3 fatty acids, a polyunsaturated fatty acid, augmentation to mood stabilizer (MS) had superiority to placebo in reducing depressive symptoms. Topiramate augmentation of an MS was equally as effective as Bupropion‐SR. Patients treated with an MS responded well to the addition of agomelatine, a melatonin receptor agonist with 5‐HT2C antagonist properties. However, inositol and repetitive transcranial magnetic stimulation did not separate from placebo. Lamotrigine and olanzapine, and to a lesser extent, divalproex, are superior to placebo in preventing depressive relapses. All agents were relatively well tolerated.Conclusions:  Olanzapine, OFC, and quetiapine are effective in the acute treatment of bipolar depression. Compared with lithium and divalproex, lamotrigine is more effective in preventing bipolar depression. Larger controlled studies of the other agents in the acute and maintenance treatment of bipolar depression are warranted.
Benefits and limitations of antidepressants and traditional mood stabilizers for treatment of bipolar depression
Authors: Goldberg Joseph F , Nassir Ghaemi S 
Published: October 2005

Objective:  The aim of this paper was to review the rationales, risks, and benefits for using standard antidepressants versus mood stabilizing agents and/or atypical antipsychotics to treat bipolar depression.Method:  A selective literature review was conducted using key terms and by reference known to the authors. Bibliographies of articles and book chapters were further scrutinized for relevant literature.Results:  The strengths and limitations of current studies are described and critically reviewed in order to present optimal strategies for effective pharmacotherapy. Clinical factors that can mitigate or confound simple bivariate relationships between antidepressant use and outcome have seldom been examined using multivariate statistical techniques. For many of the key questions there is a paucity of informative literature and randomized clinical trials are of limited value in addressing some of the issues.Conclusions:  Clinicians and investigators should be aware of the methodological shortcomings of existing studies. Decisions about the relative merits versus contraindications for antidepressant use should be made via more individualized, case‐by‐case profiling rather than by rigid prescribing practices.
Oxcarbazepine add‐on in the treatment of refractory bipolar disorder
Authors: Pratoomsri Wetid , Yatham Lakshmi N , Sohn Chang‐Ho , Solomons Kevin , Lam Raymond W 
Published: October 2005

Objective:  To assess the effectiveness and safety of oxcarbazepine (OXC) in bipolar disorder (BD) and related conditions.Methods:  We reviewed medical records of patients given OXC treatment between March 2003 and March 2005 at the University of British Columbia Hospital. Response to treatment was assessed retrospectively using the Clinical Global Impression of Severity (CGI‐S), and the Clinical Global Impression of Improvement (CGI‐I) scales.Results:  OXC was prescribed to 15 patients with bipolar I (n = 12), bipolar II (n = 2) and schizoaffective (n = 1) disorder who presented with depression (n = 9), mania (n = 3), hypomania (n = 1), or mixed state (n = 2). Six patients had Axis II diagnoses and 10 patients had a family history of mood disorders. Psychiatric co‐morbidity was found in four patients. The mean daily dose of OXC was 775 ± 556.11 mg/day and the mean duration of follow‐up was 31.60 ± 41.51 weeks. The OXC add‐on led to a significant reduction in symptoms as indicated by reduction in CGI‐S scores at 1 and 2 months. Nine of 12 patients at 1 month and seven of 14 at 1 or 2 months were much or very much improved on CGI‐I scale. One patient (7%) developed hyponatremia. Six patients (40%) experienced no side effects and three patients (20%) stopped the medication because of side effects.Conclusion:  OXC was effective and well‐tolerated in refractory BD and schizoaffective disorder. These preliminary data are promising but controlled studies are needed to confirm its efficacy in refractory BD.