bluuebunny/crossref_metadata_2025 huggingface dataset:
Links between resources, C metabolism and the major components of bacterioplankton community structure across a range of freshwater ecosystems
Authors: Comte Jérôme , Del Giorgio Paul A.
Published: March 2009

We explored the patterns in bacterioplankton community metabolism (BCM) and four components of community structure [composition (BCC), metabolic capacities (MC), physiological structure (PS) and single‐cell characteristics (SCC)], between lakes, rivers and marshes within a watershed in Québec, to assess the connections that exist between them and with the main resources (organic matter, nutrients). Habitat types were well segregated by both resources and BCM and their corresponding dissimilarity matrices were significantly correlated, suggesting that BCM tracks resource conditions in a consistent manner across ecosystem types. MC also segregated the various habitats and was correlated to BCM but less so to resources, whereas BCC at times resulted in a clear separation of habitats, but was rarely correlated to resources and never to BCM, suggesting a higher degree of ecosystem specificity at this particular level. Finally, there was no clear separation of habitats in terms of PS and SCC, and none covaried with resources or BCM. The habitat patterns based on these different components of structure were rarely correlated to each other, indicating weak deterministic connections between them. MC appears to mediate the link between resources and BCM more directly and consistently across systems; BCC appears to be more influenced by ecosystem‐specific factors that weaken its overall connection to both resources and BCM, whereas PS and SCC show no discernible patterns. Our results thus suggest that the bottom‐up regulation of BCM by resources is mediated by complex shifts within components of community structure that can be directional, ecosystem‐specific or apparently random, which combined nevertheless result in a systematic overall response to resources in terms of C metabolism.
RETRACTED: The Escherichia coli ycbQRST operon encodes fimbriae with laminin‐binding and epithelial cell adherence properties in Shiga‐toxigenic E. coli O157:H7
Authors: Samadder Partha , Xicohtencatl‐Cortes Juan , Saldaña Zeus , Jordan Dianna , Tarr Phillip I. , Kaper James B. , Girón Jorge A.
Published: March 2009

The human pathogen Shiga‐toxigenic Escherichia coli (STEC) O157:H7 contains a ycbQRST fimbrial‐like operon, which shares significant homology to the family of F17 fimbrial biogenesis genes f17ADCG found in enterotoxigenic E. coli. We report that growth of STEC O157:H7 strain EDL933 in minimal Minca medium at 37°C and during adherence to epithelial cells led to the production of fine peritrichous fimbriae, which were found to be composed of a major subunit of 18 kDa whose N‐terminal amino acid sequence matched the predicted protein product of the ycbQ gene; and showed significant homology to the F17a‐A fimbrin. Similar to the F17 fimbriae, the purified STEC fimbriae and the recombinant YcbQ protein fused to a His peptide tag bound laminin, but not fibronectin or collagen. Thus, we propose the name E. coli YcbQ laminin‐binding fimbriae (ELF) to designate the fimbriae encoded by the ycbQRST operon. The role of ELF as an adherence factor of STEC to cultured epithelial cells was investigated. We provide compelling evidence demonstrating that ELF contributes to adherence of STEC to human intestinal epithelial cells and to cow and pig gut tissue in vitro. Deletion in the fimbrin subunit gene elfA (or ycbQ) in STEC strain EDL933 led to an isogenic strain, which showed significant reduction (60%) in adherence to HEp‐2 cells in comparison with the parental strain. In addition, antibodies against the purified ELF also partially blocked adherence of two STEC O157:H7 strains. These observations suggest that ELF functions as an accessory adherence factor that, along with other known redundant adhesins, contributes to the overall adhesive properties of STEC O157:H7 providing these organisms with ecological advantages to survive in different hosts and in the environment.
Correlation of diffusion‐weighted magnetic resonance data with cellularity in prostate cancer
Authors: Zelhof Bashar , Pickles Martin , Liney Gary , Gibbs Peter , Rodrigues Greta , Kraus Sigurd , Turnbull Lindsay
Published: March 2009

OBJECTIVE

To assess the relationship between the apparent diffusion coefficient (ADC) on magnetic resonance imaging (MRI) and cell density (CD) obtained from radical prostatectomy (RP) specimens.

PATIENTS AND METHODS

In all, 36 patients with prostate cancer were recruited; T2‐weighted and diffusion‐weighted MRI was obtained axially using a 3.0 T scanner. Patients then proceeded to RP; the prostate was whole‐mounted and sectioned axially. Slices (3 µm) were cut from the surface of each section and stained with haematoxylin and eosin (H&E). Five randomly positioned areas from the tumour and normal peripheral zone (PZ) were examined by light microscopy at × 200, then digitally photographed and analysed to obtain automatic CD. ADC values were determined from the MRI data using the H&E slides as a reference. ADC and CD values were measured in both malignant lesions and the PZ, and the correlation between ADC and CD assessed.

RESULTS

ADC values were lower (P ≤ 0.001) in regions pathologically determined as tumour, with a mean (sd) of 1.45 (0.26) × 10−3 mm2/s, vs normal PZ, of 1.90 (0.33) × 10−3 mm2/s. Similarly, the mean CD over the five fields was higher (P ≤ 0.001) in tumour than in normal PZ, with values of 18.89 (4.93)% vs 9.22 (3.23)%. There was a significant correlation between the ADC values and CD (r = −0.50, P < 0.001) regardless of tissue type. CD values were high in cancer which had lower ADC values than normal PZ.

CONCLUSIONS

ADC values were correlated successfully with CD; this information cannot be obtained with conventional MRI and is useful in characterizing prostate cancer.
Postoperative surveillance for renal cell carcinoma: a multifactorial histological subtype specific protocol
Authors: Siddiqui Sameer A. , Frank Igor , Cheville John C. , Lohse Christine M. , Leibovich Bradley C. , Blute Michael L.
Published: March 2009

OBJECTIVE

To create a model that adjusts surveillance after surgery to the natural history of surgically treated renal cell carcinoma (RCC), and to assess the cost of several surveillance models with a long‐term longitudinal follow‐up, as although there are many models for predicting the outcome in RCC, most surveillance protocols remain based primarily on stage alone, and thus might be inaccurate as they do not incorporate many other pathological features that have a significant effect on recurrence.

PATIENTS AND METHODS

We identified 1864, 357 and 118 patients with pM0 clear cell, papillary and chromophobe RCC, respectively, who had a a radical or partial nephrectomy between 1970 and 2000. All recurrences were classified according to location (abdomen, thorax, bone, brain). Cox proportional hazards models were used to determine which pathological features were independently predictive of recurrence in each group. Three subtype‐specific protocols were devised based on site‐specific recurrence rates.

RESULTS

Positive surgical margins, the 2002 Tumour‐Node‐Metastasis classification, size, nuclear grade, and histological tumour necrosis were independently associated with abdominal recurrence in patients with clear‐cell RCC. These same features, except for surgical margins, were significantly associated with thoracic recurrence. The 2002 classification and nuclear grade were independently associated with abdominal and thoracic recurrence in patients with papillary RCC. No multivariate analysis was done for chromophobe RCC as there were only 10 recurrences to the abdomen and three to the thoracic region. However, these patients were stratified according to stage and grade, as recurrences in this group had a clear stage‐ and grade‐specific pattern.

CONCLUSIONS

We present a subtype‐specific multifactorial surveillance protocol based on significant predictors of recurrence. This protocol is better than algorithms based on stage alone and can be used to effectively tailor postoperative imaging to the individual patient.
NO‐FREE‐LUNCH EQUIVALENCES FOR EXPONENTIAL LÉVY MODELS UNDER CONVEX CONSTRAINTS ON INVESTMENT
Authors: Kardaras Constantinos
Published: March 2009

We provide equivalence of numerous no‐free‐lunch type conditions for financial markets where the asset prices are modeled as exponential Lévy processes, under possible convex constraints in the use of investment strategies. The general message is the following: if any kind of free lunch exists in these models it has to be of the most egregious type, generating an increasing wealth. Furthermore, we connect the previous to the existence of the numéraire portfolio, both for its particular expositional clarity in exponential Lévy models and as a first step in obtaining analogues of the no‐free‐lunch equivalences in general semimartingale models, a task that is taken on in Karatzas and Kardaras (2007).
RISK MEASURES ON ORLICZ HEARTS
Authors: Cheridito Patrick , Li Tianhui
Published: March 2009

Coherent, convex, and monetary risk measures were introduced in a setup where uncertain outcomes are modeled by bounded random variables. In this paper, we study such risk measures on Orlicz hearts. This includes coherent, convex, and monetary risk measures on Lp‐spaces for 1 ≤p < ∞ and covers a wide range of interesting examples. Moreover, it allows for an elegant duality theory. We prove that every coherent or convex monetary risk measure on an Orlicz heart which is real‐valued on a set with non‐empty algebraic interior is real‐valued on the whole space and admits a robust representation as maximal penalized expectation with respect to different probability measures. We also show that penalty functions of such risk measures have to satisfy a certain growth condition and that our risk measures are Luxemburg‐norm Lipschitz‐continuous in the coherent case and locally Luxemburg‐norm Lipschitz‐continuous in the convex monetary case. In the second part of the paper we investigate cash‐additive hulls of transformed Luxemburg‐norms and expected transformed losses. They provide two general classes of coherent and convex monetary risk measures that include many of the currently known examples as special cases. Explicit formulas for their robust representations and the maximizing probability measures are given.
Innovative Legal Approaches to Address Obesity
Authors: POMERANZ JENNIFER L. , TERET STEPHEN P. , SUGARMAN STEPHEN D. , RUTKOW LAINIE , BROWNELL KELLY D.
Published: March 2009

Context: The law is a powerful public health tool with considerable potential to address the obesity issue. Scientific advances, gaps in the current regulatory environment, and new ways of conceptualizing rights and responsibilities offer a foundation for legal innovation.

Methods: This article connects developments in public health and nutrition with legal advances to define promising avenues for preventing obesity through the application of the law.

Findings: Two sets of approaches are defined: (1) direct application of the law to factors known to contribute to obesity and (2) original and innovative legal solutions that address the weak regulatory stance of government and the ineffectiveness of existing policies used to control obesity. Specific legal strategies are discussed for limiting children's food marketing, confronting the potential addictive properties of food, compelling industry speech, increasing government speech, regulating conduct, using tort litigation, applying nuisance law as a litigation strategy, and considering performance‐based regulation as an alternative to typical regulatory actions. Finally, preemption is an overriding issue and can play both a facilitative and a hindering role in obesity policy.

Conclusions: Legal solutions are immediately available to the government to address obesity and should be considered at the federal, state, and local levels. New and innovative legal solutions represent opportunities to take the law in creative directions and to link legal, nutrition, and public health communities in constructive ways.
Reduced activation in lateral prefrontal cortex and anterior cingulate during attention and cognitive control functions in medication‐naïve adolescents with depression compared to controls
Authors: Halari Rozmin , Simic Mima , Pariante Carmine M. , Papadopoulos Andrew , Cleare Anthony , Brammer Michael , Fombonne Eric , Rubia Katya
Published: March 2009

Background:  There is increasing recognition of major depressive disorder (MDD) in adolescence. In adult MDD, abnormalities of fronto‐striatal and fronto‐cingulate circuitries mediating cognitive control functions have been implicated in the pathogenesis and been related to problems with controlling negative thoughts. No neuroimaging studies of cognitive control functions, however, exist in paediatric depression. This study investigated whether medication‐naïve adolescents with MDD show abnormal brain activation of fronto‐striatal and fronto‐cingulate networks when performing tasks of attentional and cognitive control.

Methods:  Event‐related functional magnetic resonance imaging was used to compare brain activation between 21 medication‐naïve adolescents with a first‐episode of MDD aged 14–17 years and 21 healthy adolescents, matched for handedness, age, sex, demographics and IQ. Activation paradigms were tasks of selective attention (Simon task), attentional switching (Switch task), and motor response inhibition and error detection (Stop task).

Results:  In all three tasks, adolescents with depression compared to healthy controls demonstrated reduced activation in task‐relevant right dorsolateral (DLPFC), inferior prefrontal cortex (IFC) and anterior cingulate gyrus (ACG). Additional areas of relatively reduced activation were in the parietal lobes during the Stop and Switch tasks, putamen, insula and temporal lobes during the Switch task and precuneus during the Simon task.

Conclusions:  This study shows first evidence that medication‐naïve adolescents with MDD are characterised by abnormal function in ACG and right lateral prefrontal cortex during tasks of attention and performance monitoring, suggesting an early pathogenesis of these functional abnormalities attributed to MDD.
Using species distribution models to predict new occurrences for rare plants
Authors: Williams John N. , Seo Changwan , Thorne James , Nelson Julie K. , Erwin Susan , O’Brien Joshua M. , Schwartz Mark W.
Published: March 2009

Aim To evaluate a suite of species distribution models for their utility as predictors of suitable habitat and as tools for new population discovery of six rare plant species that have both narrow geographical ranges and specialized habitat requirements.

Location The Rattlesnake Creek Terrane (RCT) of the Shasta‐Trinity National Forest in the northern California Coast Range of the United States.

Methods We used occurrence records from 25 years of US Forest Service botanical surveys, environmental and remotely sensed climate data to model the distributions of the target species across the RCT. The models included generalized linear models (GLM), artificial neural networks (ANN), random forests (RF) and maximum entropy (ME). From the results we generated predictive maps that were used to identify areas of high probability occurrence. We made field visits to the top‐ranked sites to search for new populations of the target species.

Results Random forests gave the best results according to area under the curve and Kappa statistics, although ME was in close agreement. While GLM and ANN also gave good results, they were less restrictive and more varied than RF and ME. Cross‐model correlations were the highest for species with the most records and declined with record numbers. Model assessment using a separate dataset confirmed that RF provided the best predictions of appropriate habitat. Use of RF output to prioritize search areas resulted in the discovery of 16 new populations of the target species.

Main conclusions Species distribution models, such as RF and ME, which use presence data and information about the background matrix where species do not occur, may be an effective tool for new population discovery of rare plant species, but there does appear to be a lower threshold in the number of occurrences required to build a good model.
More species, fewer specialists: 100 years of changes in community composition in an island biogeographical study
Authors: Christian Kerbiriou , Isabelle Le Viol , Frédéric Jiguet , Vincent Devictor
Published: March 2009

Aim  We measured the changes in an island avifauna over more than 100 years (1898–2006), using community indices accounting for difference in expected species sensitivity to land‐use and climate changes.

Location  Ouessant Island, France, Great Britain.

Methods  We assessed the temporal trend of the relative proportion of generalist species breeding on Ouessant island and whether high‐temperature tolerant species have replaced less tolerant species over this time period. We further tested the relationship between the observed change in the avifauna composition, and long‐term population species’ trends measured independently in potential source regions of colonist species (France and Great Britain).

Results  During the whole study period, Ouessant island has experienced a strong increase in species richness (+41%), but a severe decline in specialist species. In contrast, we found no change in species composition in terms of their temperature‐tolerance. The observed trend was highly correlated with species trends measured in the Great Britain.

Main conclusions  Our results revealed an ongoing biotic homogenization process towards more generalist species, coupled with a strong local increase in species richness. The observed trend was most likely driven by a strong habitat change in the island occurring during the period considered, favouring the colonization of generalist species. Our results show that an increase in species richness can be misinterpreted as a sign of conservation improvement and that assessing change in community composition using species‐specific ecological traits provides more accurate insights for conservation planning purposes.
Staff perceptions of e‐learning for teaching delivery in healthcare
Authors: Blake Holly
Published: March 2009

Background  Web‐based e‐learning methods are increasingly used in higher education to support learning in pre‐ and post‐registration healthcare subjects. Although new technologies are central to teaching and learning strategies, e‐learning is not currently accepted universally by academic staff.

Aim  The aim of the study was to determine the attitudes towards and use of e‐learning among academic staff in nursing and midwifery.

Methods  A questionnaire survey was completed by 102 teaching staff to determine their opinions towards and use of e‐learning in teaching.

Results  Staff opinions were divergent with most acknowledging the benefits of e‐learning but many also expressing concerns over barriers such as lack of time, resources or technical support. Staff did not fully utilize the range of technologies available.

Conclusion  Most staff exhibited positive attitudes towards the pedagogical value of technology in teaching and learning, though some remained hesitant or lacking in confidence to embark on e‐learning teaching developments or delivery. Barriers exist that may be partially addressed through better understanding of e‐learning tools and their potential application, and additional support and resources. E‐learning strategies need to focus on improving staff awareness of e‐learning methods to supplement rather than replace traditional teaching methods, while providing ongoing support and mentoring for development and delivery, technological training and incentives for staff involvement.
Sustained virological response is associated with clearance of hepatitis C virus RNA and a decrease in hepatitis C virus antibody
Authors: Maylin Sarah , Martinot‐Peignoux Michelle , Ripault Marie‐Pierre , Moucari Rami , Cardoso Ana Carolina , Boyer Nathalie , Giuily Nathalie , Castelnau Corinne , Pouteau Michelle , Asselah Tarik , Nicolas‐Chanoine Marie Hélène , Marcellin Patrick
Published: March 2009

Background/Aim: Viral eradication in chronic hepatitis C patients with sustained virological response (SVR) after interferon (IFN) therapy remains controversial.

Methods: During a long‐term follow‐up study, 157 patients with SVR to IFN‐α‐2b‐based therapy were investigated with a transcription‐mediated amplification (TMA) assay in serum. The hepatitis C virus (HCV) antibody was assessed by measuring the optical density (OD) (Axsym HCV v3.0) and the semiquantitative titres (RIBA HCV v3.0) of the HCV antibodies directed against the core, NS3, NS4 and NS5 proteins. A control group included 23 untreated patients with persistently normal serum alanine aminotransferase and detectable serum HCV‐RNA.

Results: The median duration of follow‐up was 4.0 (0–10) years. Serum HCV‐RNA remained undetectable in all patients. The mean HCV antibody OD were 93 ± 19 and 45 ± 21 before therapy and in the last available serum sample respectively (P=0.001). There was a marked decrease in the HCV antibodies directed against the NS3, NS4 and NS5 proteins (P=0.001), while the core protein titre remained strongly positive. The 23 control patients were followed for a median of 5 (2–14) years. The mean HCV antibody OD were 65 ± 14 and 64 ± 19 in the first and the last measurements, respectively (NS), and HCV antibody titres for structural and non‐structural proteins remained unchanged.

Conclusion: This long‐term study evaluating 157 patients demonstrated that SVR assessed by TMA is durable, and HCV antibodies were markedly decreased (mainly those directed against the non‐structural proteins), emphasizing an absence of ongoing infection. These results strongly suggest that HCV infection cured in patients who achieve an SVR.
Comparing and Integrating Community‐Based and Science‐Based Approaches to Prioritizing Marine Areas for Protection
Authors: BAN NATALIE C. , PICARD CHRIS R. , VINCENT AMANDA C. J.
Published: March 2009

Abstract:  We compared and integrated marine protected areas proposed through community and scientific assessments in 2 regions of British Columbia, Canada. The community priorities were identified during individual and group interviews with knowledgeable resource users. The scientific priorities were developed with abiotic and biotic data in Marxan, a decision‐support tool. The resulting maps of community‐based and science‐based priorities were very similar for the inshore areas, which lent credibility to both approaches. The resource users thought the science‐based maps were fairly good at highlighting areas important for conservation, but preferred the scenarios that integrated the 2 maps to either constituent map. Incorporating spatial variation in human impacts on the marine areas and commercial fishing, which are both costs of protection, into our Marxan analyses led to scenarios that were different from either constituent map. Our results show the value of integrating community‐based and science‐based approaches in conservation planning to achieve community acceptance and conservation utility. They also reveal that people's assessments on the basis of their traditional ecological knowledge may serve as a reasonable proxy for scientific approaches in selecting areas of ecological value.
A Genomewide Assessment of Inbreeding Depression: Gene Number, Function, and Mode of Action
Authors: AYROLES JULIEN F. , HUGHES KIMBERLY A. , ROWE KEVIN C. , REEDY MELISSA M. , RODRIGUEZ‐ZAS SANDRA L. , DRNEVICH JENNY M. , CÁCERES CARLA E. , PAIGE KEN N.
Published: March 2009

Abstract:  Although the genetic basis of inbreeding depression is still being debated, most fitness effects are thought to be the result of increased homozygosity for recessive or partially recessive deleterious alleles rather than the loss of overdominant genes. It is unknown how many loci are associated with inbreeding depression, the genes or gene pathways involved, or their mode of action. To uncover genes associated with variation in fitness following inbreeding, we generated a set of inbred lines of Drosophila melanogaster for which only the third chromosome varied among lines and measured male competitive reproductive success among these lines to estimate inbreeding depression. Male competitive reproductive success for different lines validated our prediction that equally inbred lines show variation in inbreeding depression. To begin to assess the molecular basis of inbreeding depression for male competitive reproductive success, we detected variation in whole‐genome gene expression across these inbred lines with commercially available high‐density oligonucleotide microarrays. A total of 567 genes were differentially expressed among these inbred lines, indicating that inbreeding directly or indirectly affects a large number of genes: genes that are disproportionately involved in metabolism, stress and defense responses. Subsequently, we generated a set of outbred lines by crossing the highest inbreeding depression lines to each other and contrasted gene expression between parental inbred lines and F1 hybrids with transcript abundance as a quantitative phenotype to determine the mode of action of the genes associated with inbreeding depression. Although our results indicated that approximately 75% of all genes involved in inbreeding depression were additive, partially additive, or dominant, about 25% of all genes expressed patterns of overdominance. These results should be viewed with caution given that they may be confounded by issues of statistical inference or associative overdominance.
Contribution of the Live‐Vertebrate Trade toward Taxonomic Homogenization
Authors: ROMAGOSA CHRISTINA M. , GUYER CRAIG , WOOTEN MICHAEL C.
Published: March 2009

Abstract: The process of taxonomic homogenization occurs through two mechanisms, extinctions and introductions, and leads to a reduction of global biodiversity. We used available U.S. trade data as a proxy for global trade in live vertebrates to assess the contribution of trade to the process of taxonomic homogenization. Data included all available U.S. importation and exportation records, estimation of extinction risk, and reports of establishment outside the native range for species within six vertebrate groups. Based on Monte Carlo sampling, the number of species traded, established outside of the native range, and threatened with extinction was not randomly distributed among vertebrate families. Twenty‐eight percent of vertebrate families that were traded preferentially were also established or threatened with extinction, an unusually high percentage compared with the 7% of families that were not traded preferentially but that became established or threatened with extinction. The importance of trade in homogenization of vertebrates suggests that additional efforts should be made to prevent introductions and extinctions through this medium.
The history of status epilepticus and its treatment
Authors: Neligan Aidan , Shorvon Simon D.
Published: March 2009

Despite the fact that status epilepticus was been recognized since antiquity, its existence was largely ignored until the mid‐nineteenth century. In this review we cover the medical literature of status epilepticus from the late nineteenth century until the early 1970s when the modern era of status epilepticus began. We pay particular attention to the impact of the ILAE and its principal members on the understanding and awareness of status epilepticus. We also cover the evolution of treatment regimens advocated for status epilepticus from the late nineteenth century to the early 1970s when the benzodiazepines were established as first line treatments.
Characteristics of blood donors and donated blood in sub‐Saharan Francophone Africa
Authors: Tagny Claude Tayou , Diarra Amadou , Yahaya Rakia , Hakizimana Marc , Nguessan Antoine , Mbensa Guy , Nébié Yacouba , Dahourou Honorine , Mbanya Dora , Shiboski Caroline , Murphy Edward , Lefrère Jean Jacques
Published: March 2009

BACKGROUND: The importance of blood safety in public health was recognized long ago, and data are essential to plan strategies to improve the status. This study aims to obtain data on blood donor and blood donation characteristics that would complement blood safety data from national and international organizations.

MATERIALS AND METHODS: A questionnaire was sent to seven Francophone countries (Burkina Faso, Cameroon, Congo, Ivory Coast, Mali, Niger, and Rwanda) and was structured to obtain objective data on blood donors and donated blood and in administrative and technical organization.

RESULTS: The results reflect a poor level of organization of blood transfusion centers in large regions of the African continent, insufficient supply of blood products, high prevalence of transfusion‐transmitted infections, limited financial resources, a lack of well‐trained personnel, and cultural obstacles. Six countries had less than 50% of their personnel trained in transfusion medicine. Only one country had the entire standard operating procedure written. Female donors represented less than 30% of the donors and the range of percentage of hepatitis B found in donors was 2.76% to 18.96%.

CONCLUSION: The inclusion of these regions in future blood safety surveys and in the development of national blood transfusion programs is essential and will undoubtedly require the assistance of international organizations.
Paravahlkampfia francinae n. sp. Masquerading as an Agent of Primary Amoebic Meningoencephalitis
Authors: VISVESVARA GOVINDA S. , SRIRAM RAMA , QVARNSTROM YVONNE , BANDYOPADHYAY KAKALI , DA SILVA ALEXANDRE J. , PIENIAZEK NORMAN J. , CABRAL GUY A.
Published: March 2009

ABSTRACT. Paravahlkampfia francinae n. sp., a new species of the free‐living amoeba genus Paravahlkampfia, designated as CDC:V595, was isolated from the cerebrospinal fluid of a patient with headache, sore throat, and vomiting, typical symptoms of primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri. The isolate grew at 33 °C, 37 °C, 40 °C, and 42 °C and destroyed mammalian cell cultures. However, it did not kill young mice upon intranasal inoculation. P. francinae does not produce flagellates and does not grow on agar plates coated with Gram‐negative bacteria such as Escherichia coli, the usual food source of Paravahlkampfia ustiana, the type species of the genus. The trophozoite at light microscopy exhibited eruptive locomotion and possessed a single vesicular nucleus. Ultrastructurally, the trophozoites had numerous mitochondria with discoidal cristae but did not have a Golgi apparatus. The trophozoites differentiated into cysts after consuming most of the monolayer. The cyst had an inner well‐differentiated endocyst and an outer thin, wrinkled, and wavy ectocyst with no pores. During excystation trophozoites ruptured the cyst wall and emerged from the cysts. A unique feature seen in the cysts was the presence of bacterial endosymbionts, both in the endoplasm and within the cyst wall. Full‐length sequencing analysis of the 18S and 5.8S RNA genes of P. francinae showed that they were distinct from those of other Paravahlkampfia species. The patient recovered within a few days indicating that some of the previously reported cases of PAM that survived may have been due to P. francinae.
A Call to Promote Indigenous Rights
Authors: Lutz Ellen L
Published: March 2009

Ellen Lutz is the outgoing contributing editor of “Human Rights Forum”, the AAA Committee for Human Rights column in Anthropology News. Shannon Speed is the incoming contributing editor.
A randomized study of massed three‐week cognitive behavioural therapy schedule for panic disorder
Authors: Bohni M. K. , Spindler H. , Arendt M. , Hougaard E. , Rosenberg N. K.
Published: March 2009

Objective:  To compare the efficacy of massed vs. spaced group cognitive behavioural therapy (CBT) for patients with panic disorder with or without agoraphobia (PD).

Method:  Thirty‐nine PD patients were randomly assigned to massed group CBT (daily 4‐h sessions in week 1, two 2‐h sessions in week 2 and one 2‐h session in week 3) or traditional spaced weekly group CBT (13 consecutive, weekly 2‐h sessions). The content and number of hours in the two treatment schedules were identical. Outcome was assessed after treatment, and at 3, 6 and 18 months of follow‐up.

Results:  Both treatment groups achieved significant improvement on all measures with large pre‐ to post‐treatment and pre‐treatment to follow‐up effect sizes. No between‐group differences were registered. Adherence and patient satisfaction did not differ between groups.

Conclusion:  The massed, 3‐week group CBT schedule proved to be effective and feasible for PD patients with outcomes comparable with that of standard, spaced group CBT.
Mandibular single‐implant overdentures: a review with surgical and prosthodontic perspectives of a novel approach
Authors: Alsabeeha Nabeel , Payne Alan G. T. , De Silva Rohana K. , Swain Michael V.
Published: March 2009

Objectives: To review the literature on mandibular single‐implant overdentures (opposing complete maxillary dentures), and present surgical and prosthodontic perspectives of a novel approach for this treatment option.

Material and methods: An electronic search through the databases of Pubmed, Embase and Medline using the linked key words ‘mandibular single implant overdentures’ was performed. The search was limited to English language articles published up to August 2008. Hand searches through articles retrieved from the electronic search, peer‐reviewed journals and recent conference proceedings were also conducted.

Results: A limited number of reports were identified on mandibular single‐implant overdentures (opposing maxillary complete dentures). They comprised of case‐series reports, short‐term prospective trials and current randomized‐controlled clinical trials. Different loading protocols with different implant systems have been used, but always with regular diameter implants. Specific anatomical and vascular dangers of the mandibular midline symphysis are identified including a novel surgical approach using a currently available short, wide diameter tapered implant. In addition, the prosthodontic rationale for using a larger attachment system (incorporating a platform switch) for mandibular single‐implant overdentures is described.

Conclusion: The review reveals that there is a lack of published randomized clinical trials using mandibular single‐implant overdentures, opposing maxillary complete dentures. Without the evidence from randomized clinical trials, routine use of this novel approach cannot be recommended, compared with using regular diameter implants and matching attachment systems.
Influence of the surgical technique and surface roughness on the primary stability of an implant in artificial bone with a density equivalent to maxillary bone: a laboratory study
Authors: Tabassum Afsheen , Meijer Gert J. , Wolke Johannes G. C. , Jansen John A.
Published: March 2009

Objective: The aim of this biomechanical study was to assess the effect of surgical technique and surface roughness on primary implant stability in low‐density bone.

Material and methods: Eighty screw‐shaped (Biocomp®) implants with machined or etched surface topography were inserted into a low‐density bone equivalent. Solid rigid polyurethane blocks (Sawbones®) with two different bone densities (group A=0.32 g/cm3; group B=0.48 g/cm3) were used that are very similar to the density of the maxilla. The implant sites were prepared either by a press‐fit or by an undersized technique. Peak insertion and removal torques were measured using a Digital® torque gauge instrument.

Results: Independent of the surgical technique used, both implant types showed an increased mean insertion and removal torque value with increasing bone density. Insertion and removal torque values were 54.3±5.3 and 43.5±6.5 N cm for group A and 89.3±7.6 and 55±9.1 for group B, respectively. For group A and B, both implant types showed statistically higher insertion and removal torque mean values for the undersized compared with the press‐fit technique (P<0.01). In addition, etched implants showed statistically higher insertion and removal torque mean values compared with machined implants (P<0.01).

Conclusion: The placement of etched implants in synthetic bone models using an undersized preparation technique resulted in enhanced primary implant stability; further, a correlation was found between primary stability and bone density of the synthetic bone, implying that in case of an implant site with low bone density, by changing the surgical technique and choosing an implant with an optimal surface roughness, the primary stability can be enhanced significantly.
Bacteraemia due to dental flossing
Authors: Crasta Kenneth , Daly Christopher G. , Mitchell David , Curtis Brad , Stewart Douglas , Heitz‐Mayfield Lisa J. A.
Published: March 2009

Aims: The aims of this study were to (1) investigate the incidence of bacteraemia following flossing in subjects with chronic periodontitis or periodontal health; (2) identify the micro‐organisms in detected bacteraemias; and (3) identify any patient or clinical factors associated with such bacteraemia.

Material and Methods: Baseline blood samples were obtained from 30 individuals with chronic periodontitis (17 M:13 F, 29–75 years) and 30 with periodontal health (17 M:13 F, 28–71 years) following a non‐invasive examination. Each subject's teeth were then flossed in a standardized manner and blood samples obtained 30 s and 10 min. after flossing cessation. Blood samples were cultured in a BACTEC™ system and positive samples subcultured for identification.

Results: Forty per cent of periodontitis subjects and 41% of periodontally healthy subjects tested positive for bacteraemia following flossing. Viridans streptococci, which are commonly implicated in infective endocarditis (IE), were isolated from 19% of positive subjects and accounted for 35% of microbial isolates. Twenty per cent of subjects had a detectable bacteraemia at 10 min. post‐flossing. No patient or clinical factors were significantly associated with post‐flossing bacteraemia.

Conclusions: Dental flossing can produce bacteraemia in periodontally healthy and periodontally diseased individuals at a rate comparable with that caused by some dental treatments for which antibiotic prophylaxis is given to prevent IE.
TLR4 as a risk factor for periodontal disease: a reappraisal
Authors: Ozturk Ayla , Vieira Alexandre R.
Published: March 2009

Aim: To determine whether genetic variants of the TLR4 gene are associated with either chronic or aggressive periodontitis.

Methods: A systematic electronic search of literature was conducted to identify all published studies without any language restriction on the association between TLR4 and periodontal diseases, including chronic periodontitis and aggressive periodontitis. All case–control studies evaluating the TLR4 Asp299Gly and Thr399Ile polymorphisms in chronic or aggressive periodontitis were identified. A meta‐analysis of the studies that fulfilled the inclusion criteria was performed.

Results: Seven studies comprising 744 chronic periodontitis cases and 855 controls and four studies consisting of a total of 295 aggressive periodontitis cases and 456 controls were included in the meta‐analysis. In the pooled analysis, the TLR4 299Gly allele (TLR4+896 A>G) appeared to be a genetic risk factor for susceptibility to chronic periodontitis with a random effects and fixed effects odds ratio (OR) of 1.43 [95% confidence interval (CI):1.04–1.97; p=0.03]. On the other hand, the TLR4 399Ile polymorphism (TLR4+1196 C>T) showed a protective effect against aggressive periodontitis with a random effects OR of 0.29 (95% CI: 0.13–0.61; p=0.001).

Conclusion: Our results suggest that the alleles 299Gly and 399Ile in TLR4 can be a potential genetic marker for periodontal disease.
Essential oils in one‐stage full‐mouth disinfection: double‐blind, randomized clinical trial of long‐term clinical, microbial and salivary effects
Authors: Cortelli Sheila Cavalca , Cortelli José Roberto , Holzhausen Marinella , Franco Gilson Cesar Nobre , Rebelo Renato Zanotta , Sonagere Alan Salinas , Queiroz Celso da Silva , Costa Fernando Oliveira
Published: March 2009

Aim: This randomized clinical trial evaluated the effects of an essential oils‐containing mouthrinse for full‐mouth disinfection.

Material and Methods: Fifty patients were assigned to receive full‐mouth disinfection with either essential oils or placebo. At baseline, 2 and 6 months of treatment the primary outcomes probing depth (PD), plaque index (PlI) and modified gingival index (MGI) were monitored. Additional monitoring included bacterial presence (by polymerase chain reaction) in subgingival, saliva and tongue samples; flows, pH, total protein and alkaline phosphatase salivary levels. The following statistics were used: anova, Student's t‐test, χ2 and Kruskal–Wallis (p<0.05).

Results: Mean PD3.5 mm was reduced over time in both the placebo and the test groups, but there was no difference in PD reduction between groups at 2 and 6 months. At 2 and 6 months, PlI and MGI showed greater reductions in the test group than in the placebo group. Porphyromona gingivalis was not reduced in any site. At 6 months, Campylobacter rectus increased in both groups, while Tannerella forsythensis decreased subgingivally in the test group. S. sanguinis increased, except subgingivally, in the placebo group. Salivary pH and flows were not altered. Total protein reduced only in the test group. Alkaline phosphatase did not change in either group.

Conclusions: Essential oils for full‐mouth disinfection showed clinical benefits, namely reducing plaque and gingival inflammation without altering basic salivary parameters.
Dose–response relationship between periodontal inflamed surface area and HbA1c in type 2 Diabetics
Authors: Nesse Willem , Linde Annemiek , Abbas Frank , Spijkervet Frederik Karst Lucien , Dijkstra Pieter Ubele , De Brabander Eric Carl , Gerstenbluth Izzy , Vissink Arjan
Published: March 2009

Background: A dose–response relationship between the amount of inflamed periodontal tissue and HbA1c level, might be indicative for a causal association between periodontitis and type 2 diabetes.

Aim: To assess a dose–response relationship between the periodontal inflamed surface area (PISA), as a measure of the amount of inflamed periodontal tissue, and HbA1c levels in type 2 diabetics.

Material and Methods: Forty consecutive dentate type 2 diabetics attending their general practitioner for regular check‐up, underwent full‐mouth probing pocket depth and bleeding on probing assessment. From these data PISA was calculated. HbA1c levels were retrieved from patients' medical files. The dose–response relationship between PISA and HbA1c levels was assessed using multiple linear regression analyses, controlling for factors that might influence PISA or HbA1c levels.

Results: The higher the PISA of type 2 diabetics was, the higher their HbA1c levels were. On a group level, an increase of PISA with 333 mm2 was associated with a 1.0 percentage point increase of HbA1c, independent of the influence of other factors.

Conclusion: On a group level, there is a dose–response relationship between PISA and HbA1c in type 2 diabetics. This might be an indication of a causal relationship between type 2 diabetes and periodontitis.
Interleukin‐2 in the development and control of inflammatory disease
Authors: Hoyer Katrina K. , Dooms Hans , Barron Luke , Abbas Abul K.
Published: March 2009

Summary: Interleukin‐2 (IL‐2) has multiple, sometimes opposing, functions during an inflammatory response. It is a potent inducer of T‐cell proliferation and T‐helper 1 (Th1) and Th2 effector T‐cell differentiation and provides T cells with a long‐lasting competitive advantage resulting in the optimal survival and function of memory cells. In a regulatory role, IL‐2 is important for the development, survival, and function of regulatory T cells, it enhances Fas‐mediated activation‐induced cell death, and it inhibits the development of inflammatory Th17 cells. Thus, in its dual and contrasting functions, IL‐2 contributes to both the induction and the termination of inflammatory immune responses.
Interleukin‐10: new perspectives on an old cytokine
Authors: Mosser David M. , Zhang Xia
Published: March 2009

Summary: Interleukin‐10 (IL‐10) has long been recognized to have potent and broad‐spectrum anti‐inflammatory activity, which has been unequivocally established in various models of infection, inflammation, and even in cancer. However, because of the marginal successes of the initial clinical trials using recombinant IL‐10, some of the interest in this cytokine as an anti‐inflammatory therapeutic has diminished. New work showing IL‐10 production from regulatory T cells and even T‐helper 1 T cells has reinvigorated the field and revealed the power of this cytokine to influence immune responses. Furthermore, new preclinical studies suggest that combination therapies, using antibodies to IL‐10 along with chemotherapy, can be effective in treating bacterial, viral, or neoplastic diseases. Studies to understand IL‐10 gene expression in the various cell types may lead to new therapeutics to enhance or inhibit IL‐10 production. In this review, we summarize what is known about the regulation of IL‐10 gene expression by various immune cells. We speculate on the promise that this cytokine holds to influence immune responses and mitigate immune pathologies.
Regulation and pro‐inflammatory function of interleukin‐17 family cytokines
Authors: Dong Chen
Published: March 2009

Summary: The interleukin‐17 (IL‐17) family consists of six cytokines in mammals. Among them, IL‐17 and IL‐17F are expressed by a novel subset of CD4+ helper T cells and play critical function in inflammation and autoimmunity. IL‐17E, also called IL‐25, has been associated with allergic responses. Here, I summarize recent work by my laboratory as well as other investigators in understanding the regulation and function of these three cytokines. From these studies, IL‐17 family cytokines may serve as novel targets for pharmaceutical intervention of immune and inflammatory diseases.
Early evolution of vertebrate photoreception: lessons from lampreys and lungfishes
Authors: COLLIN Shaun P.
Published: March 2009

Lampreys (Agnatha) and lungfish (Dipnoi) are representatives of the earliest and the intermediate stages in vertebrate evolution, respectively, and survived in the Cambrian (approximately 540 mA, lampreys) and Devonian (approximately 400 mA, lungfishes) Periods. The unique phylogenetic position of these two groups presents us with an exciting opportunity to understand life in ancient times and to begin to trace the evolution of vision and photoreception in vertebrates. Using a multidisciplinary approach employing anatomical and molecular techniques, the evolution of photoreception is explored in these extant, living fossils to predict the environmental lighting conditions to which our vertebrate ancestors were exposed. Contrary to expectations, the retinae of the southern hemisphere lamprey (Geotria australis Gray, 1851) and the Australian lungfish (Neoceratodus forsteri Krefft, 1870) are far from “primitive,” each possessing five types of photoreceptors, many with spectral filters for tuning the light. Detailed ultrastructural analysis reveals that all five receptor types in G. australis are cone‐like, whereas N. forsteri possesses four cone types and a single type of rod. Each receptor type also contains a different visual pigment (opsin gene); that is, LWS, SWS1, SWS2, RhA and RhB in G. australis and LWS, SWS1, SWS2, Rh1 and Rh2 in N. forsteri, all of which are expressed within the retina and are sensitive to different parts of the electromagnetic spectrum, providing the potential for pentachromatic and tetrachromatic color vision, respectively.