bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of novel interchangeable pistons for pressure performance optimization in a gas-operated dead weight pressure balance
Authors: Wan Mohamed W A M , Petzing J N
Published: May 2009

The texture of surfaces within a piston–cylinder assembly (PCA) can influence the pressure performance of gas-operated dead weight pressure balances (DWPBs). In order to systematically study this response, it has been necessary to design, develop and manufacture uniquely interchangeable 35 mm diameter PCAs for use in a novel hybrid gas-operated DWPB with high mechanical, thermal and pressure stability. This work reports the development of the PCAs and the validation of the DWPB design, allowing the performance characteristics of the interchangeable PCAs to be understood, in terms of variations of effective area calculations. This is achieved by investigating the pressure responses of the DWPBs by changing the speed and direction of rotation. The results demonstrate the stability of the gas-operated DWPB design when used in gauge mode, and importantly allow the verification of the performance of the interchangeable PCAs.
The Ups and Downs of Family Life: Det Norske Nitridaktieselskap, 1912–1976
Authors: Storli Espen , Brégaint David
Published: May 2009

The current literature on international joint ventures pays considerable attention to why joint ventures are established or why they are dissolved, but we lack studies that give insight into their dynamic development. The aim of this article is to investigate the evolution of an international joint venture over time. We confront some of the theoretical insights developed during the last decades with the dramatic history of the aluminum producer Det Norske Nitridaktieselskap (DNN). The company was established shortly beforeWorld War I and was finally disbanded over seventy years later. For most of this time, DNN was an international joint venture with shifting ownership configurations. This gives us the possibility not only to discuss the motivation for why the company was established or why it was dissolved, but also to study the mid-life of the company. What was DNN's role within the general corporate strategies of the owners? Did this role change over time?
Enolase from Paracoccidioides brasiliensis: isolation and identification as a fibronectin-binding protein
Authors: Donofrio Fabiana Cristina , Calil Ana Carolina Alvarez , Miranda Elaine Toscano , Almeida Ana Marisa Fusco , Benard Gil , Soares Christiane Pienna , Veloso Sarah Nogueira , Soares Célia Maria de Almeida , Mendes Giannini Maria José Soares
Published: May 2009

Paracoccidioides brasiliensisyeast cells can enter mammalian cells and may manipulate the host cell environment to favour their own growth and survival. Moreover, fibronectin and several other host extracellular matrix proteins are recognized by various components of the yeast cell extracts. The present study was designed to isolate and characterize a fibronectin-binding protein fromP. brasiliensis. We also comparedP. brasiliensisstrain 18, tested before (Pb18a) and after (Pb18b) animal passage, in relation to its adhesion and invasion processes. Extracts from both samples, when cultured on blood agar solid medium, showed higher levels of protein expression than when the same samples were cultured on Fava-Netto solid medium, as demonstrated by two-dimensional electrophoresis and SDS-PAGE. Also, both Pb18a and Pb18b exhibited stronger adhesion to A549 epithelial cells when cultured on blood agar medium than when cultured on Fava-Netto medium. Ligand affinity binding assays revealed a protein of 54 kDa and pI 5.6 inP. brasiliensiscell-free extracts with the properties of a fibronectin-binding adhesin, which was characterized by tryptic digestion and mass spectroscopy as a homologue of enolase fromP. brasiliensis. Antibody raised against this 54 kDa protein abolished 80 % ofP. brasiliensisadhesion to A549 epithelial cells. Our results demonstrate thatP. brasiliensisproduces a fibronectin-binding adhesin, irrespective of the culture medium, and that this activity can be inhibited by a specific antibody and is involved in the adhesion of the fungus to pulmonary epithelial cells.
Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions
Authors: O'May Che Y. , Sanderson Kevin , Roddam Louise F. , Kirov Sylvia M. , Reid David W.
Published: May 2009

The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres. CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P. aeruginosa. In contrast, the biological chelator lactoferrin demonstrated enhanced anti-biofilm effects as iron supplementation increased. Hence biofilm inhibition by lactoferrin appeared to occur through more complex mechanisms to those of the synthetic chelators. Overall, our results demonstrate the importance of iron availability to biofilms and that iron chelators have potential as adjunct therapies for preventing biofilm development, especially under low oxygen conditions such as encountered in the chronically infected CF lung.
Identification and characterization of a laminin-binding protein of Aspergillus fumigatus: extracellular thaumatin domain protein (AfCalAp)
Authors: Upadhyay Santosh Kumar , Mahajan Lakshna , Ramjee Sandhya , Singh Yogendra , Basir Seemi Farhat , Madan Taruna
Published: May 2009

Aspergillus fumigatus, an opportunistic fungal pathogen, infects the human host via inhalation of airborne conidia. Adhesion of fungal conidia, to host cells and extracellular matrix (ECM) components associated with host tissue surfaces, is thought to be the primary step in the pathogenesis and dissemination of infection. To identify novel adhesion proteins (adhesins) of A. fumigatus, we screened its proteome in silico using spaan (software program for prediction of adhesins and adhesin-like proteins using neural networks). One of the predicted adhesin-encoding genes with a P
ad (probability of being adhesin) value >0.9, the gene encoding extracellular thaumatin domain protein (AfCalA), was cloned and expressed in Escherichia coli. Recombinant AfCalAp showed significant binding with laminin and murine lung cells. Anti-AfCalAp antibodies inhibited the binding of AfCalAp to laminin in a dose-dependent manner. Significant binding of anti-AfCalAp antibodies to 2 h swollen conidia suggests the presence of AfCalAp on the conidial surface. AfCalA transcript was not detectable in resting conidia but was detected in conidia incubated with RPMI 1640 medium in the presence and absence of lung epithelial cell line (A539)-derived ECM. Elevated levels of IgE antibodies specific to AfCalAp were observed in the sera of two out of seven patients with allergic bronchopulmonary aspergillosis. The study confirms the relevance of the bioinformatic approach for predicting fungal adhesins and establishes AfCalAp as a novel laminin-binding protein of A. fumigatus.
Performance of the Phoenix bacterial identification system compared with disc diffusion methods for identifying extended-spectrum β-lactamase, AmpC and KPC producers
Authors: Fisher Mark A. , Stamper Paul D. , Hujer Kristine M. , Love Zachary , Croft Ann , Cohen Samuel , Bonomo Robert A. , Carroll Karen C. , Petti Cathy A.
Published: May 2009

Phenotypic identification of AmpC, KPC and extended-spectrum β-lactamases (ESBLs) among members of the Enterobacteriaceae remains challenging. This study compared the Phoenix Automated Microbiology System (BD Diagnostics) with the Clinical and Laboratory Standards Institute confirmatory method to identify ESBL production among 200 Escherichia coli and Klebsiella pneumoniae clinical isolates. The Phoenix system misclassified nearly half of the isolates as ESBL-positive, requiring manual testing for confirmation. Inclusion of aztreonam±clavulanic acid (CA) and cefpodoxime±CA in the testing algorithm increased the ESBL detection rate by 6 %. Boronic acid-based screening identified 24 isolates as AmpC+, but in a subset of genotypically characterized isolates, appeared to have a high false-positivity rate. PCR screening revealed eight KPC+ isolates, all of which tested as ESBL+ or ESBL+ AmpC+ by phenotypic methods, but half were reported as carbapenem-susceptible by the Phoenix system. Overall, these results indicate that laboratories should use the Phoenix ESBL results only as an initial screen followed by confirmation with an alternative method.
Inhibitors of cellular signalling are cytotoxic or block the budded-to-hyphal transition in the pathogenic yeast Candida albicans
Authors: Toenjes Kurt A. , Stark Benjamin C. , Brooks Krista M. , Johnson Douglas I.
Published: May 2009

The pathogenic yeastCandida albicanscan grow in multiple morphological states including budded, pseudohyphal and true hyphal forms. The ability to interconvert between budded and hyphal forms, herein termed the budded-to-hyphal transition (BHT), is important forC. albicansvirulence, and is regulated by multiple environmental and cellular signals. To identify small-molecule inhibitors of known cellular processes that can also block the BHT, a microplate-based morphological assay was used to screen the BIOMOL–Institute of Chemistry and Cell Biology (ICCB) Known Bioactives collection from the ICCB-Longwood Screening Facility (Harvard Medical School, Boston, MA, USA). Of 480 molecules tested, 53 were cytotoxic toC. albicansand 16 were able to block the BHT without inhibiting budded growth. These 16 BHT inhibitors affected protein kinases, protein phosphatases, Ras signalling pathways, G protein-coupled receptors, calcium homeostasis, nitric oxide and guanylate cyclase signalling, and apoptosis in mammalian cells. Several of these molecules were also able to inhibit filamentous growth in otherCandidaspecies, as well as the pathogenic filamentous fungusAspergillus fumigatus, suggesting a broad fungal host range for these inhibitory molecules. Results from secondary assays, including hyphal-specific transcription and septin localization analysis, were consistent with the inhibitors affecting known BHT signalling pathways inC. albicans. Therefore, these molecules will not only be invaluable in deciphering the signalling pathways regulating the BHT, but also may serve as starting points for potential new antifungal therapeutics.
Genotyping of Chlamydia trachomatis from the endocervical specimens of high-risk women in Hungary
Authors: Petrovay Fruzsina , Balla Eszter , Németh István , Gönczöl Éva
Published: May 2009

The distribution of differentChlamydia trachomatisserovars in Hungary has not been reported previously. The objective of this study was to determine the distribution and prevalence ofC. trachomatisserovars in a high-risk population by genotyping. The endocervical specimens of 484 female sex workers (FSWs) were screened forC. trachomatisby plasmid PCR. Genotyping was performed in allC. trachomatis-positive samples by PCR-based RFLP analysis of theomp1gene. A total of 32 specimens (6.6 %) were positive forC. trachomatis. Age was an important risk factor forC. trachomatisinfection in FSWs. The highest prevalence was detected in women under the age of 20 (18.8 %). All positive specimens were successfully genotyped and seven serovars were identified. The most prevalent was serovar D (34.4 %), followed by E (21.9 %), F (18.8 %), G (9.4 %), J (9.4 %), H (3.1 %) and I (3.1 %). A heterogeneous distribution ofC. trachomatisserovars was observed in the study group, where the most common serovars were D, E and F comprising 75 % of the positive samples. This PCR-based RFLP method could be used in epidemiological studies on the prevalence ofC. trachomatisinfection to provide more information and to compare the serovar distribution among different cohorts.
Effects of altering the germination potential of Bacillus anthracis spores by exogenous means in a mouse model
Authors: Cote C. K. , Bozue J. , Twenhafel N. , Welkos S. L.
Published: May 2009

Inhalational anthrax is the most severe form of anthrax. It has been shown in small-animal and non-human primate models that relatively large pools of ungerminatedBacillus anthracisspores can remain within the alveolar spaces for days to weeks post-inhalation or until transported to areas more favourable for germination and bacillary outgrowth. In this study, spores of the Ames strain that were exposed to germination-inducing media prior to intranasal delivery were significantly less infectious than spores delivered in either water or germination-inhibitory medium. The effect of manipulating the germination potential of these spores within the lungs of infected mice by exogenous germination-altering media was examined. The data suggested that neither inducing germination nor inhibiting germination of spores within the lungs protected mice from the ensuing infection. Germination-altering strategies could, instead, significantly increase the severity of disease in a mouse model of inhalational anthrax when implementedin vivo. It was shown that germination-altering strategies, in this study, were not beneficial to the infected host and are impractical asin vivocountermeasures.
The utility of radioiodine uptake and thyroid scintigraphy in the diagnosis and management of hyperthyroidism
Authors: Okosieme O. E. , Chan D. , Price S. A. , Lazarus J. H. , Premawardhana L. D. K. E.
Published: May 2009

Background and objectives  The value and practice of thyroid radionuclide imaging in the diagnosis and management of hyperthyroidism is unsettled. Our objectives were to determine the influence of thyroid uptake and scintigraphy on the diagnosis of hyperthyroidism and the prediction of outcome following radioiodine therapy.

Patients and design  We reviewed records and scintigraphic studies on 881 hyperthyroid patients carried out between 2000 and 2007. The agreement between the clinical and scintigraphic diagnosis was evaluated by kappa statistics. We determined the relationship between 4‐h 123I uptake and the outcome of 131I treatment in 626 patients. A multiple logistic regression model was used to determine variables influencing treatment outcome in 1 year.

Results  The diagnostic categories were Graves’ disease (GD, n = 383), toxic multinodular goitre (n = 253), solitary toxic nodule (n = 164) and Graves’ disease coexisting with nodules (n = 81). The mean age of the patients was 58 ± 17, (M:F 160:721). There was good agreement between clinical and scintigraph diagnosis (K = 0·60, 95% CI 0·57–0·64, P < 0·001); and they were correctly matched in 74%; mismatched in 6% and indeterminate in 20% of patients. Treatment outcome was not associated with scintigraph diagnosis (P = 0·98) or radioiodine uptake at 4 h (P = 0·2). The use of antithyroid medications before treatment predicted treatment failure (odds ratio 2·0, 95% CI 1·2–3·6, P = 0·01).

Conclusion  Thyroid scintigraphy and uptake studies did not influence diagnosis or treatment outcomes in most cases of hyperthyroidism. Our findings in this retrospective study do not justify their routine use. Selective scanning will reduce cost and exposure to radioisotopes without compromising diagnostic accuracy or treatment outcomes.
Hydroperiod, predators and the distribution of physid snails across the freshwater habitat gradient
Authors: TURNER ANDREW M. , MONTGOMERY SHARON L.
Published: May 2009

1. Studies of species distributions across environmental gradients further our understanding of mechanisms regulating species diversity at the landscape scale. For some freshwater taxa the habitat gradient from small, shallow and temporary ponds to large, deep and permanent lakes has been shown to be an important environmental axis. Freshwater snails are key players in freshwater ecosystems, but there are no comprehensive studies of their distributions across the entire freshwater habitat gradient. Here we test the hypothesis that snail species in the family Physidae are distributed in a non‐random manner across the habitat gradient. We sampled the snails, their predators and the abiotic environment of 61 ponds and lakes, spanning a wide range in depth and hydroperiod.

2. Temporary habitats had the lowest biomass of predators. Shallow permanent ponds had the highest biomass of invertebrate predators but an intermediate fish biomass. Deep ponds and lakes had the highest fish biomass and intermediate invertebrate biomass. Five species of physids occurred in the regional species pool and 60 of the 61 ponds and lakes surveyed contained physid snails. Each pond and lake contained an average of just 1.2 physid species, illustrating limited membership in local communities and substantial among‐site heterogeneity in species composition.

3. Physids showed strong sorting along the habitat gradient, with Physa vernalis found in the shortest hydroperiod ponds and Aplexa elongata, P. gyrina, P. acuta and P. ancillaria found in habitats of successively greater permanence. When organised into a site‐by‐species incidence matrix with sites ordered according to their hydroperiods, we found the pattern of incidence to be highly coherent, showing that much of the heterogeneity in species composition from one pond to another is explained by hydroperiod. We also found that the number of species replacements along this gradient was higher than random, showing that replacement is more important than nesting in describing species composition in ponds of different hydroperiod.

4. Discriminant analysis showed that pond depth, invertebrate biomass and fish biomass were the best predictors of species composition. Analysis of these niche dimensions showed that P. vernalis and A. elongata were most successful in shallow, temporary ponds with few predators. P. gyrina and P. acuta were typically found in ponds of intermediate depth and high predator abundance. P. ancillaria was found in the deepest lakes, which had abundant fish predators but few invertebrate predators. Of the five species considered, P. ancillaria, P. vernalis and A. elongata were relatively specialised with regard to key habitat characteristics, P. gyrina was moderately generalised and P. acuta was remarkably generalised, since it alone occurred across the entire freshwater habitat gradient. The exceptional habitat breadth of P. acuta stands in contrast to distributional studies of other freshwater taxa and deserves further attention.
Climate‐related differences in the dominance of submerged macrophytes in shallow lakes
Authors: KOSTEN SARIAN , KAMARAINEN AMY , JEPPESEN ERIK , VAN NES EGBERT H. , PEETERS EDWIN T. H. M. , MAZZEO NÉSTOR , SASS LAURA , HAUXWELL JENNIFER , HANSEL‐WELCH NICOLE , LAURIDSEN TORBEN L. , SØNDERGAARD MARTIN , BACHMANN ROGER W. , LACEROT GISSELL , SCHEFFER MARTEN
Published: May 2009

It has been suggested that shallow lakes in warm climates have a higher probability of being turbid, rather than macrophyte dominated, compared with lakes in cooler climates, but little field evidence exists to evaluate this hypothesis. We analyzed data from 782 lake years in different climate zones in North America, South America, and Europe. We tested if systematic differences exist in the relationship between the abundance of submerged macrophytes and environmental factors such as lake depth and nutrient levels. In the pooled dataset the proportion of lakes with substantial submerged macrophyte coverage (> 30% of the lake area) decreased in a sigmoidal way with increasing total phosphorus (TP) concentration, falling most steeply between 0.05 and 0.2 mg L−1. Substantial submerged macrophyte coverage was also rare in lakes with total nitrogen (TN) concentrations above 1–2 mg L−1, except for lakes with very low TP concentrations where macrophytes remain abundant until higher TN concentrations. The deviance reduction of logistic regression models predicting macrophyte coverage from nutrients and water depth was generally low, and notably lowest in tropical and subtropical regions (Brazil, Uruguay, and Florida), suggesting that macrophyte coverage was strongly influenced by other factors. The maximum TP concentration allowing substantial submerged macrophyte coverage was clearly higher in cold regions with more frost days. This is in agreement with other studies which found a large influence of ice cover duration on shallow lakes' ecology through partial fish kills that may improve light conditions for submerged macrophytes by cascading effects on periphyton and phytoplankton. Our findings suggest that, in regions where climatic warming is projected to lead to fewer frost days, macrophyte cover will decrease unless the nutrient levels are lowered.
Solar UVB and warming affect decomposition and earthworms in a fen ecosystem in Tierra del Fuego, Argentina
Authors: ZALLER JOHANN G. , CALDWELL MARTYN M. , FLINT STEPHAN D. , BALLARÉ CARLOS L. , SCOPEL ANA L. , SALA OSVALDO E.
Published: May 2009

Combined effects of co‐occurring global climate changes on ecosystem responses are generally poorly understood. Here, we present results from a 2‐year field experiment in aCarexfen ecosystem on the southernmost tip of South America, where we examined the effects of solar ultraviolet B (UVB, 280–315 nm) and warming on above‐ and belowground plant production, C : N ratios, decomposition rates and earthworm population sizes. Solar UVB radiation was manipulated using transparent plastic filter films to create a near‐ambient (90% of ambient UVB) or a reduced solar UVB treatment (15% of ambient UVB). The warming treatment was imposed passively by wrapping the same filter material around the plots resulting in a mean air and soil temperature increase of about 1.2 °C. Aboveground plant production was not affected by warming, and marginally reduced at near‐ambient UVB only in the second season. Aboveground plant biomass also tended to have a lower C : N ratio under near‐ambient UVB and was differently affected at the two temperatures (marginal UVB × temperature interaction). Leaf decomposition of one dominant sedge species (Carex curta) tended to be faster at near‐ambient UVB than at reduced UVB. Leaf decomposition of a codominant species (Carex decidua) was significantly faster at near‐ambient UVB; root decomposition of this species tended to be lower at increased temperature and interacted with UVB. We found, for the first time in a field experiment that epigeic earthworm density and biomass was 36% decreased by warming but remained unaffected by UVB radiation. Our results show that present‐day solar UVB radiation and modest warming can adversely affect ecosystem functioning and engineers of this fen. However, results on plant biomass production also showed that treatment manipulations of co‐occurring global change factors can be overridden by the local climatic situation in a given study year.
Influence of intracoronal bleaching agents on the ultimate strength and ultrastructure morphology of dentine
Authors: Cavalli V. , Shinohara M. S. , Ambrose W. , Malafaia F. M. , Pereira P. N. R. , Giannini M.
Published: May 2009

Objective  To evaluate the effects of intracoronal bleaching on ultimate tensile strength (UTS) of sound and etched dentine and its ultrastructure morphology.

Methodology  Bovine dentine specimens with (e) or without previous etching with 37% phosphoric acid for 15 s were used for the intracoronal bleaching experiments. Teeth were randomly assigned to five treatments (n = 10): (C) control – no bleaching, (SP) sodium perborate, (CP) 35% carbamide peroxide, (25% HP) 25% hydrogen peroxide and (35% HP) 35% hydrogen peroxide. Bleaching was performed four times within a 72 h interval and afterwards, dentine pulp chamber blocks were obtained. The blocks were sectioned in 0.7 mm‐thick slices and these were trimmed to reduce the inner dentine to a dumbbell shape with a cross‐sectional area of 0.8 mm2. Specimens were tested with the microtensile method (0.5 mm min−1) and data were analysed (two‐way anova‐Tukey test, P < 0.05). Additional teeth were prepared for transmission electron microscopy (TEM) to evaluate dentine ultramorphology.

Results  The mean values of the UTS (SD) in MPa for sound dentine were: C = 48.3(8.5)a, SP = 34.6 (8.2)b, CP = 32.9 (8.9)b, 25% HP = 28.0(4.6)b, 35% HP = 26.4(6.6)b, and pre‐etched dentine: Ce = 38.9(13.8)a, SPe = 31.3 (9.3)ab, CPe = 28.4 (6.2)ab, 25% HPe = 30.0 (7.9)ab, 35% HPe =  19.9(4.6)b. Significant differences between the means are indicated by the letters. TEM observations exhibited demineralization areas for all bleaching treatments.

Conclusion  Bleaching decreased dentine UTS after treatment. Pre‐etched not‐bleached dentine (Ce) presented UTS similar to pre‐etched bleached dentine, except for 35% HPe. The decrease of UTS of bleached dentine could be attributed to ultrastructural alterations such as loss of inorganic components.
Partial pulpotomy on caries‐free teeth using enamel matrix derivative or calcium hydroxide: a randomized controlled trial
Authors: Kiatwateeratana T. , Kintarak S. , Piwat S. , Chankanka O. , Kamaolmatyakul S. , Thearmontree A.
Published: May 2009

Aim  To compare the effect of enamel matrix derivative (EMD) and calcium hydroxide [Ca(OH)2] on exposed human pulp.

Methodology  Fifteen pairs of human contralateral premolars were intentionally and partially pulpotomized. The exposed pulps were randomly capped with either EMDgel (Emdogain®) or a mix of Ca(OH)2 and sterile water. The subjects recorded pain or discomfort during the first 10 days and were also interviewed and examined by a blinded examiner at 1 day, 2 weeks, 3 and 6 months post‐operation. Periapical radiographs were taken prior to the operation, and 3 and 6 months post‐operation. After 6 months, the teeth were extracted and processed for histological evaluation. The data were described and analysed using McNemar test and Kaplan–Meier survival analysis.

Results  The EMDgel‐treated teeth had significantly less tooth hypersensitivity than the Ca(OH)2‐treated teeth during the first 2 weeks (P = 0.031) but were not significantly different after 2 weeks (P = 0.125). No detectable periapical radiographic changes were observed in any teeth and radiographic evidence of dentine bridge formation from both groups were not significantly different during the follow‐up periods (P > 0.05). Histological evaluation demonstrated that the Ca(OH)2‐treated teeth had less inflammation and more dentine bridge formation than those in the EMDgel‐treated teeth.

Conclusions  After 6 months, healthy pulps capped with Ca(OH)2 had more favourable results than counterparts capped with EMDgel. However, similar clinical and radiographic results were seen in both groups.
On the local applications of antibiotics and antibiotic‐based agents in endodontics and dental traumatology
Authors: Mohammadi Z. , Abbott P. V.
Published: May 2009

Antibiotics are a valuable adjunctive to the armamentarium available to health professionals for the management of bacterial infections. During endodontic treatment and when managing trauma to the teeth, antibiotics may be applied systemically (orally and/or parenterally) or locally (i.e. intra‐dentally via irrigants and medicaments). Due to the potential risk of adverse effects following systemic application, and the ineffectiveness of systemic antibiotics in necrotic pulpless teeth and the periradicular tissues, the local application of antibiotics may be a more effective mode for delivery in endodontics. The aim of this article was to review the history, rationale and applications of antibiotic‐containing irrigants and medicaments in endodontics and dental traumatology. The search was performed from 1981 to 2008 and was limited to English‐language papers. The keywords searched on Medline were ‘Antibiotics AND endodontics’, ‘Antibiotics AND root canal irrigation’, ‘Antibiotics AND intra‐canal medicament’, ‘Antibiotics AND Dental trauma’ and ‘Antibiotics AND root resorption’. The reference section of each article was manually searched to find other suitable sources of information. It seems that local routes of antibiotic administration are a more effective mode than systemic applications. Various antibiotics have been tested in numerous studies and each has some advantages. Tetracyclines are a group of bacteriostatic antibiotics with antibacterial substantivity for up to 12 weeks. They are typically used in conjunction with corticosteroids and these combinations have anti‐inflammatory, anti‐bacterial and anti‐resorptive properties, all of which help to reduce the periapical inflammatory reaction including clastic‐cell mediated resorption. Tetracyclines have also been used as part of irrigating solutions but the substantivity is only for 4 weeks. Clindamycin and a combination of three antibiotics (metronidazole, ciprofloxacin and minocycline) have also been reported to be effective at reducing bacterial numbers in the root canal systems of infected teeth.
Comparative study of biocompatibility of newly developed calcium phosphate‐based root canal sealers on fibroblasts derived from primary human gingiva and a mouse L929 cell line
Authors: Khashaba R. M. , Chutkan N. B. , Borke J. L.
Published: May 2009

Aim  To determine biocompatibility of three calcium phosphate cement (CPC) sealers, and to compare the cytotoxic response of human gingival fibroblasts (HGF) and one mouse fibroblast cell line (L929) to these materials.

Methodology  Monocalcium phosphate, calcium oxide and synthetic hydroxyapatite were combined with one of three aqueous solutions: modified polyacrylic acid, glass–ionomer liquid or 35% w/w polymethyl vinyl ether maleic acid to obtain Types I, IIa and III CPCs, respectively. Commercial Ca(OH)2 sealer was used as a control. The materials were packed into Teflon molds (5.5 × 3 mm), and cellular function was assessed using MTT assay. The specimens were placed immediately in contact with cells, then evaluated at (24 h, 1 week, 2 week, 3 week, 4 week, 5 week).

Results  All materials showed significant cytotoxicity for both L929 and HGF cells at 24 h except for Type III. Type I was severely toxic initially, but improved significantly (P < 0.05) over the 5 week evaluation. Types II and Ca(OH)2 were both cytotoxic over the 5 weeks. Type III CPC was equivalent to Teflon the entire time. The results showed the same rank of cytotoxicity in both cultures. The cytotoxic response decreased in the order of Type II > Ca(OH)2 > Type I > Type III overtime. L929 cells were generally more sensitive than HGF cells to the calcium hydroxide‐based sealer (Acroseal).

Conclusion  Types I and III have acceptable biologic properties for endodontic applications.
A 5‐year review of teeth filled with the noninstrumentation technology
Authors: Suter B. , Portmann P. , Lussi A.
Published: May 2009

Aim  The aim of this Case Series was to evaluate the radiographic quality of root fillings performed 5 years previously using the noninstrumentation technology (NIT)‐obturation method and to assess radiographically the outcome of these root canal treatments.

Methodology  Seventeen patients requiring root canal treatment participated in this study and were re‐evaluated after 5 years. After instrumentation with K‐Flexofiles, Calcium‐Hydroxide inter‐appointment dressing, re‐entry and copious irrigation with NaOCl, the teeth were root filled using the NIT.

Results  Immediately after obturation the root fillings were (−0.78 ± 0.11 mm) short when taking the radiographic apex as a reference point. After 60 months these values were −0.85 ± 0.11 mm. No statistical difference was found (P > 0.05). In the periapical region, PAI rating 1 and 2 increased from 20.1% to 75.6% after 60 months.

Conclusions  • This prospective Case Series demonstrated the performance of the NIT‐obturation method in vivo.

• Root canals filled by the reduced‐pressure method using sealer combined with gutta‐percha cones showed good radiographic quality.

• Periapical healing after 5 years was comparable with conventional filling techniques.
A project management perspective on student's declarative commitments to goals established within asynchronous communication
Authors: Chiocchio F. , Lafrenière A.
Published: May 2009

Teamwork and technology, even as people are seeing their increased use in organizations, are becoming important components of problem‐based learning in academic settings. Yet, fostering computer‐assisted teamwork is complex and time consuming. Knowing how and when to intervene would prove useful. This study draws from the field of project management to explore how students commit to project goals using collective asynchronous text‐based communication technology. Declarative commitments – goal‐orientated public, voluntary, explicit and non‐retractable messages comprised of a term, an objective and a focus – made by 34 teams during a four‐phase 13‐week project were analysed qualitatively and quantitatively. Qualitative results show that declarative commitments voluntarily and formally package information about project constraints into a relatively potent message about tasks, coordination and project completion. Team members' suggestions as to what should be carried out in the project and requests for help often preceded others' declarative commitments. As with persuasive communication (i.e. aimed at changing beliefs, attitudes and behaviours), declarative commitments were followed by demands for clarification, new declarative commitments, confirmations of upheld commitments and clear approvals of what was committed to. Looking at project progression from a broader perspective, quantitative analyses show that declarative commitments did partially mediate the relationship between frequencies of task issues and of task solutions. This was particularly pronounced in the mid‐point of the project, but it was not the case during the initial or final phases of the project. Taken together, these results suggest that teachers can facilitate computer‐assisted learning and project goal attainment by monitoring asynchronous electronic discussions, and by eliciting and structuring declarative commitments.
ANTI‐HSP60 and ANTI‐HSP70 antibody levels and micro/ macrovascular complications in type 1 diabetes: the EURODIAB Study
Authors: Gruden G. , Bruno G. , Chaturvedi N. , Burt D. , Pinach S. , Schalkwijk C. , Stehouwer C. D. , Witte D. R. , Fuller J. H. , Cavallo‐Perin P. ,   EURODIAB Prospective Complications Study Group
Published: May 2009

Objectives.  The heat shock proteins 60 and 70 (HSP60, HSP70) play an important role in cytoprotection. Under stress conditions they are released into the circulation and elicit an immune response. Anti‐HSP60 and anti‐HSP70 antibody levels have been associated with cardiovascular disease. Type 1 diabetes is associated with a greatly increased risk of micro‐ and macrovascular complications. Therefore, we investigated whether anti‐HSP60 and anti‐HSP70 antibody levels were associated with micro‐ and macrovascular complications in type 1 diabetic patients.

Design.  A cross‐sectional nested case‐control study from the EURODIAB Study of 531 type 1 diabetic patients was performed.

Subjects.  Cases (n = 363) were defined as those with one or more complications of diabetes; control subjects (n = 168) were all those with no evidence of any complication. We measured anti‐HSP60 and anti‐HSP70 antibody levels and investigated their cross‐sectional associations with diabetic complications.

Results.  Anti‐HSP70 antibody levels were significantly greater in control than in case subjects, whereas anti‐HSP60 antibody levels were similar in the two groups. In logistic regression analysis, anti‐HSP70 levels in the upper quartiles were associated with a 47% reduced odds ratio of micro/macrovascular complications, independently of conventional risk factors, markers of inflammation and endothelial dysfunction [odds ratio(OR) = 0.53, 95% confidence intervals(CI): 0.28–1.02].

Conclusions.  In this large cohort of type 1 diabetic subjects, we found an independent and inverse association between serum anti‐HSP70 antibody levels and diabetic micro/macrovascular complications. This suggests that anti‐HSP70 antibody levels may be a novel marker of protection from chronic diabetic complications.
Reduced glomerular filtration rate but sustained virologic response in HIV/hepatitis B co‐infected individuals on long‐term tenofovir
Authors: Tan L. K. K. , Gilleece Y. , Mandalia S. , Murungi A. , Grover D. , Fisher M. , Atkins M. , Nelson M.
Published: May 2009

Summary.  Reports have described a decrease in glomerular filtration rate (eGFR) associated with tenofovir disoproxil fumarate (TDF) use in HIV positive individuals. However, no study has examined renal function over a prolonged period in HIV/hepatitis B virus (HBV) co‐infected patients. We assessed the long‐term durability and toxicity of TDF in a cohort of 39 e antigen (eAg) positive co‐infected patients commenced on TDF 245 mg daily either in addition to or as part of standard antiretroviral therapy. Immunological and virological parameters were followed to 260 weeks, with the median follow‐up period being 251 weeks (range 69–290 weeks). eGFR was calculated using the Modification in Diet in Renal Disease equation. On treatment at 260 weeks, 88% (14/16) had HIV viral load <50 copies/mL, median CD4 count rose from 318 to 532 cells/mm3, median alanine aminotransferase (ALT) fell from 61 IU/L to 42 IU/L, with 35% (7/20) having a normal ALT, median HBV DNA fell from 69 × 106 copies/mL to 500 copies/mL, with 75% (12/16) having an undetectable HBV DNA level and 55% (6/11) becoming eAg negative. Of those with detectable HBV DNA, none had TDF resistance mutations. The eGFR declined by 22.19 mL/min/1.73 mm2 from baseline (P = 0.023) over this period, which was unaffected by protease inhibitor use, baseline CD4 count, ALT or HBV DNA level. Three patients discontinued TDF therapy due to renal dysfunction. In conclusion, TDF has sustained efficacy but is associated with a significant decline in eGFR. Further larger studies are required to clarify this observation.
Identification of exopolysaccharide‐deficient mutants of Mycoplasma pulmonis
Authors: Daubenspeck James M. , Bolland Jeffrey R. , Luo Wenyi , Simmons Warren L. , Dybvig Kevin
Published: May 2009

The presence of capsular exopolysaccharide (EPS) in Mollicutes has been inferred from electron micrographs for over 50 years without conclusive data to support the production of complex carbohydrates by the organism. Mycoplasma pulmonis binds the lectin Griffonia simplicifolia I (GS‐I), which is specific for terminal β‐linked galactose residues. Mutants that failed to produce the EPS bound by GS‐I were isolated from a transposon library. All of the mutants had the transposon located in open reading frame MYPU_7410 or MYPU_7420. These overlapping genes are predicted to code for a heterodimeric pair of ABC transporter permeases and may code for part of a new pathway for synthesis of EPS. Analysis by lectin‐affinity chromatography in conjunction with gas chromatography demonstrated that the wild‐type mycoplasma produced an EPS (EPS‐I) composed of equimolar amounts of glucose and galactose that was lacking in the mutants. Phenotypic analysis revealed that the mutants had an increased propensity to form a biofilm on glass surfaces, colonized mouse lung and trachea efficiently, but had a decreased association with the A549 lung cell line. Confounding the interpretation of these results is the observation that the mutants missing EPS‐I had an eightfold overproduction of an apparent second EPS (EPS‐II) containing N‐acetylglucosamine.
Evolution of the Nile deep‐sea turbidite system during the Late Quaternary: influence of climate change on fan sedimentation
Authors: DUCASSOU EMMANUELLE , MIGEON SÉBASTIEN , MULDER THIERRY , MURAT ANNE , CAPOTONDI LUCILLA , BERNASCONI STEFANO M. , MASCLE JEAN
Published: May 2009

This paper presents an overview of the evolution of the Nile deep‐sea turbidite system during the last 200 kyr, over a series of glacial to interglacial cycles. Six individual deep‐sea fans were identified from an extensive field data set. Each fan comprises a canyon, channel system and terminal lobes. Two of these fan systems were possibly active at the same time, at least during some periods. Large‐scale slope failures destroyed channel segments and caused the formation of new submarine fan systems. These slope failures thus played an important role in the overall evolution of the turbidite system. During the last glacial maximum (ca 25 to 14·8 ka) the central and eastern parts of the Nile deep‐sea turbidite system were relatively inactive. This inactivity corresponds to a lowstand in sea‐level, and a period of arid climate and relatively low sediment discharge from the Nile fluvial system. Rapid accumulation of fluvial flood‐derived deposits occurred across the shallower part of the submarine delta during sea‐level rise between ca 14·8 and 5 ka. The most recent deep‐sea channel–lobe system was very active during this period of rising sea‐level, which is also associated with a wetter continental climate and increased sediment and water discharge from the Nile. Increased sediment deposition in shallower water areas led to occasional large‐scale slope failure. The Nile deep‐sea turbidite system was largely inactive after ca 5 ka. This widespread inactivity is due to retreat of the coastline away from the continental shelf break, and to a more arid continental climate and reduced discharge of sediment from the Nile. The Nile deep‐sea turbidite system may be more active during periods of rising and high sea‐level associated with wetter climates, than during lowstands, and may rapidly become largely inactive during highstands in sea‐level coupled with arid periods. These acute responses to climate change have produced sedimentary/stratigraphic features that diverge from traditional sequence models in their nature and timing. This large‐scale sedimentary system responded to monsoon‐driven climate change and sea‐level change in a system‐wide and contemporaneous manner.
The case for pancreas after kidney transplantation
Authors: Fridell Jonathan A. , Mangus Richard S. , Hollinger Edward F. , Taber Tim E. , Goble Michelle L. , Mohler Elaine , Milgrom Martin L. , Powelson John A.
Published: May 2009

Abstract:  Pancreas after kidney (PAK) transplantation has historically demonstrated inferior pancreas allograft survival compared to simultaneous pancreas and kidney (SPK) transplantation. Under our current immunosuppression protocol, we have noted excellent outcomes and rare immunological graft loss. The goal of this study was to compare pancreas allograft survival in PAK and SPK recipients using this regimen. This was a single center retrospective review of all SPK and PAK transplants performed between January 2003 and November 2007. All transplants were performed with systemic venous drainage and enteric exocrine drainage. Immunosuppression included induction with rabbit anti‐thymocyte globulin (thymoglobulin), early steroid withdrawal, and maintenance with tacrolimus and sirolimus or mycophenolate mofetil. Study end points included graft and patient survival and immunosuppression related complications. Transplants included PAK 61 (30%) and SPK 142 (70%). One‐yr patient survival was PAK 98% and SPK 95% (p = 0.44) and pancreas graft survival was PAK 95% and SPK 90% (p = 0.28). Acute cellular rejection was uncommon with 2% requiring treatment in each group. Survival for PAK using thymoglobulin induction, early steroid withdrawal and tacrolimus‐based immunosuppression is at least comparable to SPK and should be pursued in the recipient with a potential living donor.
Cortical folding difference between patients with early‐onset and patients with intermediate‐onset bipolar disorder
Authors: Penttilä Jani , Cachia Arnaud , Martinot Jean‐Luc , Ringuenet Damien , Wessa Michèle , Houenou Josselin , Galinowski André , Bellivier Frank , Gallarda Thierry , Duchesnay Edouard , Artiges Eric , Leboyer Marion , Olié Jean‐Pierre , Mangin Jean‐François , Paillère‐Martinot Marie‐Laure
Published: May 2009

Objectives:  Cerebral abnormalities have been detected in patients with bipolar disorder (BD). In comparison to BD with a later onset, early‐onset BD has been found to have a poorer outcome. However, it is yet unknown whether neuroanatomical abnormalities differ between age‐at‐onset subgroups of the illness. We searched for cortical folding differences between early‐onset (before 25 years) and intermediate‐onset (between 25 and 45 years) BD patients.

Methods:  Magnetic resonance images of 22 early‐onset BD patients, 14 intermediate‐onset BD patients, and 50 healthy participants were analyzed using a fully automated method to extract, label, and measure the sulcal area in the whole cortex. Cortical folding was assessed by computing global sulcal indices (the ratio between total sulcal area and total outer cortex area) for each hemisphere, and local sulcal indices for 12 predefined regions in both hemispheres.

Results:  Intermediate‐onset BD patients had a significantly reduced local sulcal index in the right dorsolateral prefrontal cortex in comparison to both early‐onset BD patients and healthy subjects, and lower global sulcal indices in both hemispheres in comparison to healthy subjects (p < 0.05, Bonferroni corrected). Brain tissue volumes did not differ between groups.

Conclusions:  This study provided the first evidence of a neuroanatomic difference between intermediate‐onset and early‐onset BD, which lends further support to the existence of different age‐at‐onset subgroups of BD.
Retrospective age at onset of bipolar disorder and outcome during two‐year follow‐up: results from the STEP‐BD study
Authors: Perlis Roy H , Dennehy Ellen B , Miklowitz David J , DelBello Melissa P , Ostacher Michael , Calabrese Joseph R , Ametrano Rebecca M , Wisniewski Stephen R , Bowden Charles L , Thase Michael E , Nierenberg Andrew A , Sachs Gary
Published: May 2009

Objective:  Symptoms of bipolar disorder are increasingly recognized among children and adolescents, but little is known about the course of bipolar disorder among adults who experience childhood onset of symptoms.

Methods:  We examined prospective outcomes during up to two years of naturalistic treatment among 3,658 adult bipolar I and II outpatients participating in a multicenter clinical effectiveness study, the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP‐BD). Age at illness onset was identified retrospectively by clinician assessment at study entry.

Results:  Compared to patients with onset of mood symptoms after age 18 years (n = 1,187), those with onset before age 13 years (n = 1,068) experienced earlier recurrence of mood episodes after initial remission, fewer days of euthymia, and greater impairment in functioning and quality of life over the two‐year follow‐up. Outcomes for those with onset between age 13 and 18 years (n = 1,403) were generally intermediate between these two groups.

Conclusion:  Consistent with previous reports in smaller cohorts, adults with retrospectively obtained early‐onset bipolar disorder appear to be at greater risk for recurrence, chronicity of mood symptoms, and functional impairment during prospective observation.