bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of cerebral cranium volumes between cavalier King Charles spaniels with Chiari‐like malformation, small breed dogs and Labradors
Authors: Cross H. R. , Cappello R. , Rusbridge C.
Published: August 2009

Objectives: To ascertain whether cavalier King Charles spaniels (CKCSs) have a proportionately smaller caudal fossa compared with other small dogs and with Labradors. To evaluate if cerebellar herniation in CKCS correlates with caudal fossa volume.

Methods: In this retrospective study, three‐dimensional images were created from magnetic resonance imaging brain series of 117 dogs (split into three groups: CKCS, Labradors and small breeds) from which the volumes of the fossae and brain parenchyma were calculated. These volumes were transformed into percentages of total cranial cavity and parenchyma volumes, respectively. The percentages were statistically compared among the groups. The percentage of herniated cerebellum in the CKCS was compared using linear regression with the caudal fossa and parenchyma percentages.

Results: Cavalier King Charles spaniels had a proportionately smaller caudal fossa compared with Labradors (P=0·002) but not to small breeds (P=0·103). Their caudal fossa parenchyma was proportionately the same volume as Labradors (P=0·976) but greater than small breeds (P=0·005). No relationship was found for the per cent of cerebellum herniated.

Clinical Significance: The results support mesoderm insufficiency or craniosynostosis as the pathogenesis of Chiari‐like malformation (CM) in CKCS. It presents evidence for overcrowding of the caudal fossa due to a mismatch of brain parenchyma and fossa volumes as to why CKCS and not other small dogs are affected.
BSAVA Manual of Canine and Feline Thoracic Imaging
Authors: Maddox Thomas W.
Published: August 2009

BSAVA Manual of Canine and Feline Thoracic Imaging

Edited by Tobias Schwarz and Victoria Johnson

Published by the British Small Animal Veterinary Association, 2008, 1st edition, paperback, 396 pages. Price £80, ISBN‐13: 978‐0905214979
Poverty, Relationship Conflict, and the Regulation of Cortisol in Small and Large Group Contexts at Child Care
Authors: Rappolt‐Schlichtmann Gabrielle , Willett John B. , Ayoub Catherine C. , Lindsley Robert , Hulette Annmarie C. , Fischer Kurt W.
Published: August 2009

The purpose of this research is to explore the dynamics of cortisol regulation in the context of center‐based child care by examining the impact of social context (large classroom vs. small group) and relationship quality with caregivers (conflict with mothers and teachers). We extend the research on children's physiologic stress system functioning in center‐based child care by focusing on morning cortisol levels among young children living in poverty. While in high‐quality center‐based child care, children's cortisol levels decreased over the course of the morning—a result that contrasts with findings in previous research with middle‐class children, for whom cortisol typically increased over the course of the day while attending center‐based child care. Cortisol levels were further reduced when children were moved from a large classroom environment to a small group context. Relationship conflict with mothers and teachers moderated these effects. Children who had high conflict with their mother exhibited cortisol levels that remained higher (decreased less) over the course of the morning, and children who had high conflict with their teacher exhibited cortisol levels that remained higher (decreased less) in response to the small group context. These results indicate that high‐quality child care has the potential to support reduced stress among children living in poverty, at least as indicated by adrenocortical activity.
The Logarithmic‐To‐Linear Shift: One Learning Sequence, Many Tasks, Many Time Scales
Authors: Siegler Robert S. , Thompson Clarissa A. , Opfer John E.
Published: August 2009

The relation between short‐term and long‐term change (also known as learning and development) has been of great interest throughout the history of developmental psychology. Werner and Vygotsky believed that the two involved basically similar progressions of qualitatively distinct knowledge states; behaviorists such as Kendler and Kendler believed that the two involved similar patterns of continuous growth; Piaget believed that the two were basically dissimilar, with only development involving qualitative reorganization of existing knowledge and acquisition of new cognitive structures. This article examines the viability of these three accounts in accounting for the development of numerical representations. A review of this literature indicated that Werner's and Vygotsky's position (and that of modern dynamic systems and information processing theorists) provided the most accurate account of the data. In particular, both changes over periods of years and changes within a single experimental session indicated that children progress from logarithmic to linear representations of numerical magnitudes, at times showing abrupt changes across a large range of numbers. The pattern occurs with representations of whole number magnitudes at different ages for different numerical ranges; thus, children progress from logarithmic to linear representations of the 0–100 range between kindergarten and second grade, whereas they make the same transition in the 0–1,000 range between second and fourth grade. Similar changes are seen on tasks involving fractions; these changes yield the paradoxical finding that young children at times estimate fractional magnitudes more accurately than adults do. Several different educational interventions based on this analysis of changes in numerical representations have yielded promising results.
Capturing the Complexity of Moral Development and Education
Authors: Nucci Larry , Turiel Elliot
Published: August 2009

This article discusses challenges educators face when attempting to sequence moral education. Two factors are identified as primary sources hindering efforts to engage in effective moral education: (a) the premature application of research findings from developmental psychology to classroom practices and (b) the underestimation of the complexity of interactions between development in students' social and moral understandings and their applications in social contexts. Research is reviewed demonstrating that morality develops alongside concepts about societal conventions and zones of personal discretion and privacy. Results of an ongoing study are presented pointing toward a U‐shaped pattern in moral development in which frequency of moral choices is higher among younger children and older adolescents than among early adolescents. Research examining contextual moral decision making is discussed in relation to efforts to sequence moral education.
On Grandmother Neurons and Grandfather Clocks
Authors: Perkins David
Published: August 2009

What does contemporary neuroscience offer educational practice? The promise seems immense, as we come to understand better how the brain learns. However, critics caution that only a few concrete implications for practice have emerged, nowhere near a rewrite of the craft of teaching and learning. How then can we understand better the relationship between neuroscience and educational practice? It is argued here that to speak to the classroom neuroscience has to shout across two gaps. The first and most familiar are different levels of explanation. The second concerns the epistemological contrast between explanation theories and action theories, roughly the contrast between basic science on the one hand and engineering science and craft on the other. Just as we do not expect Newton's laws in their fundamental generality to deliver specific designs for pocket watches and grandfather clocks, neither should we expect fundamental neuroscience to radically redesign particular practices of teaching and learning grounded in educational research and experience.
Mind, Brain, and Literacy: Biomarkers as Usable Knowledge for Education
Authors: Goswami Usha
Published: August 2009

Neuroscience has the potential to make some very exciting contributions to education and pedagogy. However, it is important to ask whether the insights from neuroscience studies can provide “usable knowledge” for educators. With respect to literacy, for example, current neuroimaging methods allow us to ask research questions about how the brain develops networks of neurons specialized for the act of reading and how literacy is organized in the brain of a reader with developmental dyslexia. Yet quite how these findings can translate to the classroom remains unclear. One of the most exciting possibilities is that neuroscience could deliver “biomarkers” that could identify children with learning difficulties very early in development. In this review, I will illustrate how the field of mind, brain, and education might develop biomarkers by combining educational, cognitive, and neuroscience research paradigms. I will argue that all three kinds of research are necessary to provide usable knowledge for education.
The assessment of insemination success in yellow dung flies using competitive PCR
Authors: BUSSIÈRE L. F. , DEMONT M. , PEMBERTON A. J. , HALL M. D. , WARD P. I.
Published: August 2009

In spite of considerable interest in postcopulatory sexual selection, separating the effects of sperm competition from cryptic female choice remains difficult because mechanisms underlying postcopulatory processes are poorly understood. One methodological challenge is to quantify insemination success for individual males within the sperm stores of multiply mated females to discover how insemination translates into eventual paternity. Any proposed method must be applicable in organisms without extensive DNA sequence information (which include the majority of model species for sexual selection). Here, we describe the development and application of microsatellite competitive‐multiplex‐PCR for quantifying relative contributions to a small number of sperm in storage. We studied how DNA template characteristics affect PCR amplification of known concentrations of mixed DNA and generated regressions for correcting observations of allelic signal strength based on such characteristics. We used these methods to examine patterns of sperm storage in twice‐mated female yellow dung flies, Scathophaga stercoraria. We confirm previous findings supporting sperm displacement and demonstrate that average paternity for the last mate accords with the mean proportion of sperm stored. We further find consistent skew in storage across spermathecae, with more last male sperm stored in the singlet spermatheca on one side of the body than in the doublet on the opposite side. We also show that the time between copulations may be important for effectively sorting sperm. Finally, we demonstrate that male size may influence the opportunity for sperm choice, suggesting future work to disentangle the roles of male competition and cryptic female choice.
Locke on Sensitive Knowledge as Knowledge1
Authors: STAPLEFORD SCOTT
Published: August 2009

This article is an extended analysis of the most recent scholarly work on Locke's account of sensitive knowledge. Lex Newman's “dual cognitive relations” model of sensitive knowledge is examined in detail. The author argues that the dual cognitive relations model needs to be revised on both philosophical and historical grounds. While no attempt is made to defend Locke's position, the aim is to show that it is at least consistent, contrary to the received view. The final section provides textual support for the interpretation.
Two Notions of Epistemic Normativity
Authors: Klausen Søren Harnow
Published: August 2009

The overwhelmingly dominant view of epistemic normativity has been an extreme form of deontology. I argue that although the pull towards deontology is quite understandable, given the traditional concerns of epistemology, there is no good reason for not also adopting a complementary consequentialist notion of epistemic normativity, which can be put to use in applied epistemology. I further argue that this consequentialist notion is not, despite appearances and popular sentiment to the contrary, any less genuinely epistemic than the deontological notion and that it may even be considered more genuinely normative.
Prasugrel: A Novel Platelet ADP P2Y12 Receptor Antagonist
Authors: Wilson William , Gurvitch Ronen , Ajani Andrew E.
Published: August 2009

The antiplatelet drug prasugrel is one of the new generations of thienopyridines, drugs that inhibit the platelet P2Y12 receptor. It is becoming clear that there is variability in individual responses to antiplatelet agents such as clopidogrel, which may limit their efficacy and widespread utility. A number of controversies remain, such as varied definitions of “nonresponders” to antiplatelet therapy, the optimal means of assessing platelet function, and the potential capacity of in vivo platelet function studies to predict future clinical events. Prasugrel provides more rapid and consistent platelet inhibition than does clopidogrel, yet its clinical utility is under scrutiny. We aim to review the available data evaluating the efficacy and safety of this novel antiplatelet agent.
Secondary Prevention in Concurrent Coronary Artery, Cerebrovascular, and Chronic Kidney Disease: Focus on Pharmacological Therapy
Authors: Notaro Lawrence A. , Usman Mohammed H. , Burke James F. , Siddiqui Aqeel , Superdock Keith R. , Ezekowitz Michael D.
Published: August 2009

Patients with coronary artery disease (CAD) commonly have varying degrees of coexisting cerebrovascular disease (CVD) and chronic kidney disease (CKD), and proper management is complicated partly because of a lack of unifying guidelines. The aim of this article is to review the current literature and propose the optimal treatment regimen in patients with all three disease states. Angiotensin‐converting enzyme inhibitors (ACE‐I) should be universally administered. High‐dose statin therapy to reach a target low‐density lipoprotein (LDL) of 70–100 mg/dL is advocated, although patients with a history of cerebral bleeding must be carefully monitored for possible recurrence. Beta‐blockers are appropriate after a recent coronary event, and amlodipine or thiazide diuretics should be used after a recent stroke (within 6 months). Patients with a history of stroke (with or without coexisting CAD and CKD) should receive aspirin (75–150 mg/day) indefinitely. Clopidogrel or aspirin plus extended‐release dipyridamole (ER‐DP) may be prescribed in patients allergic or resistant to aspirin. If stroke is attributable to cardiogenic embolism, anticoagulation is indicated. In patients with acute coronary syndromes (ACS) (excluding ST‐elevated myocardial infarct) who undergo percutaneous coronary intervention (PCI), aspirin plus clopidogrel is indicated for secondary prevention for up to 12 months. There are no data supporting the use of aspirin plus clopidogrel in patients with CKD who develop ACS. Aspirin plus clopidogrel is contraindicated for stroke prevention.
The Effect of Beta‐Blockers on the Adaptive Immune System in Chronic Heart Failure
Authors: Shaw Steven M. , Coppinger Teresa , Waywell Carolyn , Dunne Louise , Archer Louise D. , Critchley William R. , Yonan Nizar , Fildes James E. , Williams Simon G.
Published: August 2009

It remains possible that the benefit from beta‐blockers (BBs) in chronic heart failure (CHF) may not entirely be derived from a class‐specific effect. Several experimental reports have alluded to the capability of immunomodulation by individual BBs. Given the increasingly recognized importance of the immune system in the pathogenesis of CHF, we studied the effects of BBs on the circulating immune system of these patients. Blood samples from CHF outpatients were prospectively analyzed using flow cytometry and gating software. Results were analyzed against comprehensive clinical details that were recorded during sample donation, including the type of BB administered. 273 blood samples were analyzed from 141 CHF patients, with an average ejection fraction of 31.9% and a mean age of 69.1 years. Patients taking carvedilol had a significantly lower expression of CD107a on cytotoxic T cells compared to bisoprolol (P= 0.001) and nebivolol (P= 0.008). They also had a significantly lower expression of HLA‐DR on lymphocytes (P < 0.001 and P= 0.009 for bisoprolol and nebivolol, respectively). Cytotoxic T cells and lymphocytes expressing HLA‐DR have been implicated in the pathogenesis of CHF. The fact that carvedilol, but not other commonly used beta‐blockers, appears to modulate these important parameters, supports the concept that important differences exist between these agents, which may affect outcomes in CHF.
Drug Treatment and Cost of Cardiovascular Disease in Australia
Authors: Ademi Zanfina , Liew Danny , Chew Derek , Conner Greg , Shiel Louise , Nelson Mark , Soman Ash , Steg Gabriel , Bhatt Deepak L. , Reid Christopher ,   on behalf of the REACH registry investigators
Published: August 2009

Australia's Pharmaceutical Benefits Scheme supports the use of effective drugs for the prevention and control of cardiovascular risk factors. However, there are little data available describing per person costs of medication in primary prevention and secondary prevention in the community. We aim to understand annual expenditure on cardiovascular medicines according to the level and extent of cardiovascular disease, using participants enrolled in the Reduction of Atherothrombosis for Continued Health (REACH) registry. 2873 participants were recruited into the REACH registry through 273 Australian general practices. Cardiovascular medicines review was undertaken at baseline. Average weighted costs of medications were estimated using government‐reimbursed prices. Annual costs were stratified by disease extent and location. The annual mean cost of pharmaceuticals per person was AU$1307. The average reported medicine use per person across all states and participants groups varied significantly. Participants with cerebrovascular or peripheral arterial disease were prescribed less cardiovascular medication than those with coronary artery disease (CAD) (mean number of drugs 3.5 vs. 4.5, P < 0.0001) and (3.6 vs. 4.5, P < 0.0001), while those with risk factor alone had the same medication use as those with CAD (mean number 4.5). Medication use was lower in Western Australia in comparison to eastern States. Participants with existing cerebrovascular disease and peripheral vascular disease receive less preventive therapy than those with CAD or even risk factors alone. This observation is consistent across all mainland states. Given the evidence of the effectiveness and cost‐effectiveness of treating all types of vascular diseases, the present study suggests that there is scope to improve the treatment of these high‐risk participants in Australia.
Neuroendocrine Effects on the Heart and Targets for Therapeutic Manipulation in Heart Failure
Authors: Chaggar Parminder S. , Malkin Chris J. , Shaw Steven M. , Williams Simon G. , Channer Kevin S.
Published: August 2009

Chronic heart failure (CHF) involves derangements in multiple neurohormonal axes leading to a procatabolic state and wasting syndrome associated with significant mortality. Catabolic abnormalities include excess catecholamines and glucocorticoids. Anabolic defects include deficiencies of sex steroids, insulin resistance, and growth hormone (GH) resistance. These abnormalities are also correlated with increased morbidity and mortality in CHF. Anabolic axes have been augmented in pilot studies in CHF with testosterone, GH, insulin‐like growth factor‐1, and GH secretagogues. Results have been varied although some treatments have been associated with improved surrogate endpoints. This review article explores the current understanding of metabolic derangements in CHF and highlights potential neuroendocrine treatment strategies.
ASSESSING AND TRAINING PATIENTS ON PERITONEAL DIALYSIS IN THEIR OWN HOMES CAN INFLUENCE BETTER PRACTICE
Authors: Ozturk Savas , Yucel Lamia , Guvenc Sinem , Ekiz Serpil , Kazancioglu Rumeyza
Published: August 2009

Peritoneal dialysis (PD) offers the opportunity of a better quality of life for patients as long as they are able to perform dialysis according to the set procedures. Our aim in this study was to assess the change in PD patients’ knowledge about their treatment and practice through repeated home visits. This study was based on the findings of a previous study. Fifteen patients participated and received two visits post training. During the visits, a questionnaire was completed, and the answers were analysed. Data were analysed by percentage statistics and assessed for differences between the two visits. The correct number of answers given during the first visit was 25.5 ± 3.2/31 and was 27.8 ± 4.0/31.8 at the second visit. The mean infection section and medication scores had increased from the original study findings. The personal hygiene section was the least correctly answered section. Consecutive home visits revealed that as the time on PD increased, knowledge and practice regarding infections and medication increased. Personal hygiene scores did not improve. This study confirmed the importance of home visits in detecting the weakest point of PD practice.
A SURVEY OF STRESS, JOB SATISFACTION AND BURNOUT AMONG HAEMODIALYSIS STAFF
Authors: Ross Jamie , Jones Julia , Callaghan Patrick , Eales Sarah , Ashman Neil
Published: August 2009

Background: Burnout, psychological distress and job satisfaction experienced by healthcare workers in general are well documented in the literature; however, there is a paucity of research that focuses on the experiences of haemodialysis staff. Method: The study investigates burnout, psychological distress and job satisfaction in a sample of 50 haemodialysis staff from two units in one National Health Service (NHS) trust in London, England, using the Maslach Burnout Inventory (MBI), General Health Questionnaire (GHQ‐12) and the Minnesota Satisfaction Questionnaire (MSQ).

Results: The majority of staff did not experience burnout or psychological distress and were satisfied with their jobs. However, some participants had low personal accomplishment and were dissatisfied with certain areas of their jobs. Age and length of haemodialysis experience were associated with burnout, job satisfaction and psychological distress.

Conclusions: Older staff and staff with a greater length of service in haemodialysis have higher levels of burnout, psychological distress and job dissatisfaction.
“EVERYONE SHOULD BUTTONHOLE”: A NOVEL TECHNIQUE FOR A REGIONAL AUSTRALIAN RENAL SERVICE
Authors: Hartig Vicki , Smyth Wendy
Published: August 2009

The buttonhole, or constant‐site, cannulation technique, although used elsewhere, had not been used in North Queensland, Australia, prior to 2005. This paper reports the results from a survey of patients’ and nurses’ initial experiences with the buttonhole cannulation technique 20 months after its introduction into a renal service in North Queensland. The use of the buttonhole technique increased the ease and decreased the discomfort associated with access cannulation for both patients and nurses; both groups reported less anxiety associated with this technique. The patients were especially pleased with the improved cosmetic appearance and indicated that they would be more likely to become involved in self‐care, including self‐cannulation. The nursing service has implemented strategies to ensure that buttonhole cannulation continues to be used as one means of arteriovenous fistula access across the region. A current study is examining longer‐term outcomes of using the buttonhole technique within this regional service.
GABA blockade unmasks an OFF response in ON direction selective ganglion cells in the mammalian retina
Authors: Ackert Jessica M. , Farajian Reza , Völgyi Béla , Bloomfield Stewart A.
Published: August 2009

One unique subtype of retinal ganglion cell is the direction selective (DS) cell, which responds vigorously to stimulus movement in a preferred direction, but weakly to movement in the opposite or null direction. Here we show that the application of the GABA receptor blocker picrotoxin unmasks a robust excitatory OFF response in ON DS ganglion cells. Similar to the characteristic ON response of ON DS cells, the masked OFF response is also direction selective, but its preferred direction is opposite to that of the ON component. Given that the OFF response is unmasked with picrotoxin, its direction selectivity cannot be generated by a GABAergic mechanism. Alternatively, we find that the direction selectivity of the OFF response is blocked by cholinergic drugs, suggesting that acetylcholine release from presynaptic starburst amacrine cells is crucial for its generation. Finally, we find that the OFF response is abolished by application of a gap junction blocker, suggesting that it arises from electrical synapses between ON DS and polyaxonal amacrine cells. Our results suggest a novel role for gap junctions in mixing excitatory ON and OFF signals at the ganglion cell level. We propose that OFF inputs to ON DS cells are normally masked by a GABAergic inhibition, but are unmasked under certain stimulus conditions to mediate optokinetic signals in the brain.
Adenosine signalling at immature parallel fibre–Purkinje cell synapses in rat cerebellum
Authors: Atterbury Alison , Wall Mark J.
Published: August 2009

The purine adenosine is an extracellular signalling molecule involved in a large number of physiological and pathological conditions throughout the mammalian brain. However little is known about how adenosine release and its subsequent clearance change during brain development. We have combined electrophysiology and microelectrode biosensor measurements to investigate the properties of adenosine signalling at early stages of cerebellar development, when parallel fibre–Purkinje cell synapses have recently been formed (postnatal days 9–12). At this stage of development, we could detect little or no inhibitory A1receptor tone in basal conditions and during trains of stimuli. Addition of pharmacological agents, to inhibit adenosine clearance, had only minor effects on synaptic transmission suggesting that under basal conditions, the concentration of adenosine moving in and out of the extracellular space is small. Active adenosine release was stimulated with hypoxia and trains of electrical stimuli. Although hypoxia released significant concentrations of adenosine, the release was delayed and slow. No adenosine release could be detected following electrical stimulation in the molecular layer. In conclusion, at this stage of development, although adenosine receptors and the mechanisms of adenosine clearance are present there is very little adenosine release.
The Structure of the Dizinc Subclass B2 Metallo-β-Lactamase CphA Reveals that the Second Inhibitory Zinc Ion Binds in the Histidine Site
Authors: Bebrone Carine , Delbrück Heinrich , Kupper Michaël B. , Schlömer Philipp , Willmann Charlotte , Frère Jean-Marie , Fischer Rainer , Galleni Moreno , Hoffmann Kurt M. V.
Published: August 2009

Bacteria can defend themselves against β-lactam antibiotics through the expression of class B β-lactamases, which cleave the β-lactam amide bond and render the molecule harmless. There are three subclasses of class B β-lactamases (B1, B2, and B3), all of which require Zn
2+
for activity and can bind either one or two zinc ions. Whereas the B1 and B3 metallo-β-lactamases are most active as dizinc enzymes, subclass B2 enzymes, such as
Aeromonas hydrophila
CphA, are inhibited by the binding of a second zinc ion. We crystallized
A. hydrophila
CphA in order to determine the binding site of the inhibitory zinc ion. X-ray data from zinc-saturated crystals allowed us to solve the crystal structures of the dizinc forms of the wild-type enzyme and N220G mutant. The first zinc ion binds in the cysteine site, as previously determined for the monozinc form of the enzyme. The second zinc ion occupies a slightly modified histidine site, where the conserved His118 and His196 residues act as metal ligands. This atypical coordination sphere probably explains the rather high dissociation constant for the second zinc ion compared to those observed with enzymes of subclasses B1 and B3. Inhibition by the second zinc ion results from immobilization of the catalytically important His118 and His196 residues, as well as the folding of the Gly232-Asn233 loop into a position that covers the active site.
The Electricidal Effect Is Active in an Experimental Model of
Staphylococcus epidermidis
Chronic Foreign Body Osteomyelitis
Authors: Del Pozo Jose L. , Rouse Mark S. , Euba Gorane , Kang Cheol-In , Mandrekar Jayawant N. , Steckelberg James M. , Patel Robin
Published: August 2009

Treatment with low-amperage (200 μA) electrical current was compared to intravenous doxycycline treatment or no treatment in a rabbit model of
Staphylococcus epidermidis
chronic foreign body osteomyelitis to determine if the electricidal effect is active in vivo. A stainless steel implant and 10
4
CFU of planktonic
S. epidermidis
were placed into the medullary cavity of the tibia. Four weeks later, rabbits were assigned to one of three groups with treatment administered for 21 days. The groups included those receiving no treatment (
n
= 10), intravenous doxycycline (
n
= 14; 8 mg/kg of body weight three times per day), and electrical current (
n
= 15; 200 μA continuous delivery). Following treatment, rabbits were sacrificed and the tibias quantitatively cultured. Bacterial load was significantly reduced in the doxycycline (median, 2.55 [range, 0.50 to 6.13] log
10
CFU/g of bone) and electrical-current (median, 1.09 [range, 0.50 to 2.99] log
10
CFU/g of bone) groups, compared to the level for the control group (median, 4.16 [range, 3.70 to 5.66] log
10
CFU/g of bone) (
P
< 0.0001). Moreover, treatment with electrical current was statistically significantly more efficacious (
P
= 0.035) than doxycycline treatment. The electricidal effect (the bactericidal activity of low-amperage electrical current against bacterial biofilms) is active in vivo in the treatment of experimental
S. epidermidis
chronic foreign body osteomyelitis.
Impact of
sarA
on Daptomycin Susceptibility of
Staphylococcus aureus
Biofilms In Vivo
Authors: Weiss Elizabeth C. , Zielinska Agnieszka , Beenken Karen E. , Spencer Horace J. , Daily Sonja J. , Smeltzer Mark S.
Published: August 2009

We used a murine model of catheter-associated biofilm formation to determine whether the mutation of the staphylococcal accessory regulator (
sarA
) has an impact on the susceptibility of established
Staphylococcus aureus
biofilms to treatment with daptomycin in vivo. The experiments were done with two clinical isolates, one of which (UAMS-1) was obtained from the bone of a patient suffering from osteomyelitis, while the other (UAMS-1625) is an isolate of the USA300 clonal lineage of community-acquired methicillin (meticillin)-resistant
S. aureus
. UAMS-1625 had a reduced capacity to form a biofilm in vivo compared to that of UAMS-1 (
P
= 0.0015), but in both cases the mutation of
sarA
limited biofilm formation compared to that of the corresponding parent strain (
P
≤ 0.001). The mutation of
sarA
did not affect the daptomycin MIC for either strain, but it did result in increased susceptibility in vivo in the context of an established biofilm. Specifically, daptomycin treatment resulted in the clearance of detectable bacteria from <10% of the catheters colonized with the parent strains, while treatment with an equivalent daptomycin concentration resulted in the clearance of 46.4% of the catheters colonized with the UAMS-1
sarA
mutant and 69.1% of the catheters colonized with the UAMS-1625
sarA
mutant. In the absence of daptomycin treatment, mice with catheters colonized with the UAMS-1625 parent strain also developed skin lesions in the region adjacent to the implanted catheter. No such lesions were observed in any other experimental group, including untreated mice containing catheters colonized with the UAMS-1625
sarA
mutant.
Novel Antimalarial Aminoquinolines: Heme Binding and Effects on Normal orPlasmodium falciparum-Parasitized Human Erythrocytes
Authors: Omodeo-Salè Fausta , Cortelezzi Lucia , Basilico Nicoletta , Casagrande Manolo , Sparatore Anna , Taramelli Donatella
Published: August 2009

Two new quinolizidinyl-alkyl derivatives of 7-chloro-4-aminoquinoline, named AM-1 and AP4b, which are highly effective in vitro against both the D10 (chloroquine [CQ] susceptible) and W2 (CQ resistant) strains ofPlasmodium falciparumand in vivo in the rodent malaria model, have been studied for their ability to bind to and be internalized by normal or parasitized human red blood cells (RBC) and for their effects on RBC membrane stability. In addition, an analysis of the heme binding properties of these compounds and of their ability to inhibit beta-hematin formation in vitro has been performed. Binding of AM1 or AP4b to RBC is rapid, dose dependent, and linearly related to RBC density. Their accumulation in parasitized RBC (pRBC) is increased twofold compared to levels in normal RBC. Binding of AM1 or AP4b to both normal and pRBC is higher than that of CQ, in agreement with the lower pKaand higher lipophilicity of the compounds. AM1 or AP4b is not hemolytic per se and is less hemolytic than CQ when hemolysis is accelerated (induced) by hematin. Moreover, AM-1 and AP4b bind heme with a stoichiometry of interaction similar to that of CQ (about 1:1.7) but with a lower affinity. They both inhibit dose dependently the formation of beta-hematin in vitro with a 50% inhibitory concentration comparable to that of CQ. Taken together, these results suggest that the antimalarial activity of AM1 or AP4b is likely due to inhibition of hemozoin formation and that the efficacy of these compounds against the CQ-resistant strains can be ascribed to their hydrophobicity and capacity to accumulate in the vacuolar lipid (elevated lipid accumulation ratios).
In Vitro Activities of Panduratin A against Clinical
Staphylococcus
Strains
Authors: Rukayadi Yaya , Lee Kwanghyung , Han Sunghwa , Yong Dongeun , Hwang Jae-Kwan
Published: August 2009

In vitro antistaphylococcal activities of panduratin A, a natural chalcone compound isolated from
Kaempferia pandurata
Roxb, were compared to those of commonly used antimicrobials against clinical staphylococcal isolates. Panduratin A had a MIC at which 90% of bacteria were inhibited of 1 μg/ml for clinical staphylococcal isolates and generally was more potent than commonly used antimicrobials.
In Vitro Bactericidal Activity of Iclaprim in Human Plasma
Authors: Laue Heike , Valensise Tiziana , Seguin Aurélie , Lociuro Sergio , Islam Khalid , Hawser Stephen
Published: August 2009

This study evaluated the effect of human plasma on the in vitro bactericidal activity of the novel diaminopyrimidine iclaprim against methicillin (meticillin)-susceptible and -resistant
Staphylococcus aureus
strains. MICs and minimal bactericidal concentrations (MBCs) of iclaprim, with ∼93% protein binding, were similar in the absence and in the presence of 50% human plasma; MICs and MBCs ranged from 0.06 to 0.125 μg/ml. Furthermore, the activity of iclaprim was not affected by plasma, with ≥99.9% reduction in CFU after 5.0 to 7.6 h.
Porphyromonas gingivalis
Outer Membrane Vesicles Enter Human Epithelial Cells via an Endocytic Pathway and Are Sorted to Lysosomal Compartments
Authors: Furuta Nobumichi , Tsuda Kayoko , Omori Hiroko , Yoshimori Tamotsu , Yoshimura Fuminobu , Amano Atsuo
Published: August 2009

Porphyromonas gingivalis
, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including major fimbriae and proteases termed gingipains, although it is not confirmed whether MVs enter host cells. In this study, we analyzed the mechanisms involved in the interactions of
P. gingivalis
MVs with human epithelial cells. Our results showed that MVs swiftly adhered to HeLa and immortalized human gingival epithelial cells in a fimbria-dependent manner and then entered via a lipid raft-dependent endocytic pathway. The intracellular MVs were subsequently routed to early endosome antigen 1-associated compartments and then were sorted to lysosomal compartments within 90 min, suggesting that intracellular MVs were ultimately degraded by the cellular digestive machinery. However,
P. gingivalis
MVs remained there for over 24 h and significantly induced acidified compartment formation after being taken up by the cellular digestive machinery. In addition, MV entry was shown to be mediated by a novel pathway for transmission of bacterial products into host cells, a Rac1-regulated pinocytic pathway that is independent of caveolin, dynamin, and clathrin. Our findings indicate that
P. gingivalis
MVs efficiently enter host cells via an endocytic pathway and survive within the endocyte organelles for an extended period, which provides better understanding of the role of MVs in the etiology of periodontitis.
Characterization of a Unique ADP-Ribosyltransferase of
Mycoplasma penetrans
Authors: Johnson Coreen , Kannan T. R. , Baseman Joel B.
Published: August 2009

Mycoplasma penetrans
is a urogenital tract pathogen implicated in the deterioration of the immune system in human immunodeficiency virus-infected AIDS patients. Here, we describe a 78-kDa protein from
M. penetrans
, designated MYPE9110, that exhibits sequence similarity to known ADP-ribosyltransferases (ADPRTs) such as
Bordetella pertussis
pertussis toxin and
Mycoplasma pneumoniae
community-acquired respiratory distress syndrome toxin. MYPE9110 possesses key amino acid residues found in all ADPRTs that are essential for ADPRT activity. Several mammalian cell proteins are ADP-ribosylated by MYPE9110, and the full-length recombinant protein exhibits a strong auto-ADP-ribosylating activity. In the absence of target proteins, MYPE9110 demonstrates a NAD-glycohydrolase activity by hydrolyzing NAD. Furthermore, this toxin elicits cytopathology in HeLa cells by inducing cytoplasmic vacuolization in the presence of ammonium chloride. The deletion of the C-terminal region of MYPE9110 significantly diminishes its binding to host cells while still exhibiting an ADPRT activity, suggesting that MYPE9110 is a member of the family of A-B ADPRT toxins.
Expression of Nlrp1b Inflammasome Components in Human Fibroblasts Confers Susceptibility to Anthrax Lethal Toxin
Authors: Liao Kuo-Chieh , Mogridge Jeremy
Published: August 2009

Anthrax lethal toxin causes macrophages and dendritic cells from some mouse strains to undergo caspase-1-dependent cell death. Central to this process is the NOD-like receptor Nlrp1b (Nalp1b), which detects intoxication and then self-associates to form a complex, termed an inflammasome, that is capable of activating the procaspase-1 zymogen. The nature of the signal detected directly by Nlrp1b is not known, and the mechanisms of inflammasome assembly are poorly understood. Here, we demonstrate that transfection of human fibroblasts with plasmids encoding murine Nlrp1b and procaspase-1 was sufficient to confer susceptibility to lethal toxin-mediated death on the cells. As has been observed in murine macrophages, the enzymatic activities of lethal toxin and the proteasome were both required for activation of the Nlrp1b inflammasome and this activation led to prointerleukin-1β processing. Release of interleukin-1β from cells was not dependent on cell lysis, as its secretion was not affected by an osmoprotectant that prevented the appearance of lactate dehydrogenase in the culture medium. We generated constitutively active mutants of Nlrp1b by making amino-terminal deletions to the protein and observed that the ability to activate procaspase-1 was dependent on the CARD domain, which bound procaspase-1, and a region adjacent to the CARD domain that promoted self-association. Our results demonstrate that lethal toxin can activate Nlrp1b in a nonmyeloid cell line and are consistent with work that suggests that activation induces proximity of procaspase-1.
Nuclear Translocated
Ehrlichia chaffeensis
Ankyrin Protein Interacts with a Specific Adenine-Rich Motif of Host Promoter and Intronic
Alu
Elements
Authors: Zhu Bing , Nethery Kimberly A. , Kuriakose Jeeba A. , Wakeel Abdul , Zhang Xiaofeng , McBride Jere W.
Published: August 2009

Ehrlichiae are obligately intracellular bacteria that reside and replicate in phagocytes by circumventing host cell defenses and modulating cellular processes, including host cell gene transcription. However, the mechanisms by which ehrlichiae influence host gene transcription have largely remained undetermined. Numerous ankyrin and tandem repeat-containing proteins associated with host-pathogen interactions have been identified in
Ehrlichia
species, but their roles in pathobiology are unknown. In this study, we determined by confocal immunofluorescence microscopy and by immunodetection in purified nuclear extracts that the ankyrin repeat-containing protein p200 is translocated to the nuclei of
Ehrlichia-
infected monocytes. Chromatin immunoprecipitation (ChIP) with DNA sequencing revealed an
Ehrlichia chaffeensis
p200 interaction located within host promoter and intronic
Alu-Sx
elements, the most abundant repetitive elements in the human genome. A specific adenine-rich (mid-A-stretch) motif within
Alu-Sx
elements was identified using electrophoretic mobility shift and NoShift assays. Whole-genome analysis with ChIP and DNA microarray analysis (ChIP-chip) determined that genes (
n
= 456) with promoter
Alu
elements primarily related to transcription, apoptosis, ATPase activity, and structural proteins associated with the nucleus and membrane-bound organelles were the primary targets of p200. Several p200 target genes (encoding tumor necrosis factor alpha, Stat1, and CD48) associated with ehrlichial pathobiology were strongly upregulated during infection, as determined by quantitative PCR. This is the first study to identify a nuclear translocation of bacterially encoded protein by
E. chaffeensis
and to identify a specific binding motif and genes that are primary targets of a novel molecular strategy to reprogram host cell gene expression to promote survival of the pathogen.
Plasmodium falciparum-Specific Cellular Immune Responses after Immunization with the RTS,S/AS02D Candidate Malaria Vaccine in Infants Living in an Area of High Endemicity in Mozambique
Authors: Barbosa Arnoldo , Naniche Denise , Aponte John J. , Manaca M. Nelia , Mandomando Inacio , Aide Pedro , Sacarlal Jahit , Renom Montse , Lafuente Sarah , Ballou W. Ripley , Alonso Pedro L.
Published: August 2009

Results from clinical trials in areas where malaria is endemic have shown that immunization with RTS,S/AS02A malaria vaccine candidate induces partial protection in adults and children and cellular effector and memory responses in adults. For the first time in a malaria vaccine trial, we sought to assess the cell-mediated immune responses to RTS,S antigen components in infants under 1 year of age participating in a clinical phase I/IIb trial of RTS,S/AS02D in Mozambique. Circumsporozoite protein (CSP)-specific responses were detected in approximately half of RTS,S-immunized infants and included gamma interferon (IFN-γ), interleukin-2 (IL-2), and combined IL-2/IL-4 responses. The median stimulation indices of cytokine-producing CD4+and CD8+cells were very low but significantly higher in RTS,S-immunized infants than in infants that received the comparator vaccine. Protection against subsequent malarial infection tended to be associated with a higher percentage of individuals with CSP-specific IL-2 in the supernatant (P= 0.053) and with higher CSP-specific IFN-γ-producing CD8+T-cell responses (P= 0.07). These results report for the first time the detection of malaria-specific cellular immune responses after vaccination of infants less than 1 year of age and pave the way for future field studies of cellular immunity to malaria vaccine candidates.
Nitrite Reductase NirS Is Required for Type III Secretion System Expression and Virulence in the Human Monocyte Cell Line THP-1 by
Pseudomonas aeruginosa
Authors: Van Alst Nadine E. , Wellington Melanie , Clark Virginia L. , Haidaris Constantine G. , Iglewski Barbara H.
Published: August 2009

The nitrate dissimilation pathway is important for anaerobic growth in
Pseudomonas aeruginosa
. In addition, this pathway contributes to
P. aeruginosa
virulence by using the nematode
Caenorhabditis elegans
as a model host, as well as biofilm formation and motility. We used a set of nitrate dissimilation pathway mutants to evaluate the virulence of
P. aeruginosa
PA14 in a model of
P. aeruginosa
-phagocyte interaction by using the human monocytic cell line THP-1. Both membrane nitrate reductase and nitrite reductase enzyme complexes were important for cytotoxicity during the interaction of
P. aeruginosa
PA14 with THP-1 cells. Furthermore, deletion mutations in genes encoding membrane nitrate reductase (Δ
narGH
) and nitrite reductase (Δ
nirS
) produced defects in the expression of type III secretion system (T3SS) components, extracellular protease, and elastase. Interestingly, exotoxin A expression was unaffected in these mutants. Addition of exogenous nitric oxide (NO)-generating compounds to Δ
nirS
mutant cultures restored the production of T3SS phospholipase ExoU, whereas nitrite addition had no effect. These data suggest that NO generated via nitrite reductase NirS contributes to the regulation of expression of selected virulence factors in
P. aeruginosa
PA14.
Role of Phosphatidylinositol Mannosides in the Interaction between Mycobacteria and DC-SIGN
Authors: Driessen Nicole N. , Ummels Roy , Maaskant Janneke J. , Gurcha Sudagar S. , Besra Gurdyal S. , Ainge Gary D. , Larsen David S. , Painter Gavin F. , Vandenbroucke-Grauls Christina M. J. E. , Geurtsen Jeroen , Appelmelk Ben J.
Published: August 2009

The C-type lectin dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) is the major receptor on DCs for mycobacteria of theMycobacterium tuberculosiscomplex. Recently, we have shown that although the mannose caps of the mycobacterial surface glycolipid lipoarabinomannan (ManLAM) are essential for the binding to DC-SIGN, genetic removal of these caps did not diminish the interaction of whole mycobacteria with DC-SIGN and DCs. Here we investigated the role of the structurally related glycolipids phosphatidylinositol mannosides (PIMs) as possible ligands for DC-SIGN. In a binding assay with both synthetic and natural PIMs, DC-SIGN exhibited a high affinity for hexamannosylated PIM6, which contains terminal α(1→2)-linked mannosyl residues identical to the mannose cap on ManLAM, but not for di- and tetramannosylated PIM2and PIM4, respectively. To determine the role of PIM6in the binding of whole mycobacteria to DC-SIGN, a mutant strain ofM. bovisbacillus Calmette-Guérin deficient in the production of PIM6(ΔpimE) was created, as well as a double knockout deficient in the production of both PIM6and the mannose caps on LAM (ΔpimEΔcapA). Compared to the wild-type strain, both mutant strains bound similarly well to DC-SIGN and DCs. Furthermore, the wild-type and mutant strains induced comparable levels of interleukin-10 and interleukin-12p40 when used to stimulate DCs. Hence, we conclude that, like ManLAM, PIM6represents a bona fide DC-SIGN ligand but that other, as-yet-unknown, ligands dominate in the interaction between mycobacteria and DCs.