bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Events and Labour Mobility: Relocations in the Wake of the Ansett Airlines Collapse
Authors: WELLER SALLY
Published: August 2009

Migration plays an important role in neo‐liberal regional adjustment. This paper explores the role of economic shocks in stimulating internal migration within Australia. Drawing on the experiences of retrenched Ansett Airlines employees, it argues that economic crisis impels some households to relocate but traps others in places with restricted employment prospects. For some, the crisis of retrenchment triggers inter‐state migration to take up new jobs. For others, it prompts relocation to less expensive housing, often in a geographically proximate location. These opposing responses, which are different outcomes of similar causal processes, exacerbate regional inequalities since they selectively encourage younger skilled workers to enter growing regions. The combination of high housing costs and insecure employment discourages speculative migration. The paper concludes with a brief discussion of the policy implications of these findings.
The Tung Oil Boom in Australasia: a Network Perspective
Authors: ROCHE MICHAEL
Published: August 2009

Ideas about networks are explored in the context of the interest within the British Empire and the United States of America in planting Tung Oil trees (Aleurites fordii) during the 1920s and 1930s. Closer attention is paid to the Australian and New Zealand experience and short‐lived enthusiasm for the search for seeds, the collation of information on growth rates, and the planting of Tung trees. The paper briefly distinguishes various types of network research in human geography and concludes by raising some questions about space and time in network approaches in the social sciences more generally.
Geographical Influences on Settlement‐Location Choices by Initial Colonizers: a Case Study of the Fiji Islands
Authors: NUNN PATRICK D.
Published: August 2009

From 3200 to 2850 cal BP (1250–900 BCE), the Lapita people of the Bismarck Archipelago (Papua New Guinea) undertook voyages eastward that led to their colonization of the eastern outer Solomon Islands, Vanuatu, New Caledonia, Fiji, Tonga and Samoa. The earliest (Lapita) settlements in Fiji were along the Rove Peninsula in southwest Viti Levu Island. At the time of colonization, sea level was 1.5 m higher than today. The Rove Peninsula was then a smaller island off the coast of larger Viti Levu, with a broad, fringing reef along its windward coasts, which was probably the main attraction for Lapita colonizers. As elsewhere during Lapita times in the western tropical Pacific Islands, settlement choice for the initial colonizers of the Fiji Islands was at one level driven by site access, at another by the presence of broad, fringing coral reefs suitable for marine foraging.

The earliest settlement along the Rove Peninsula was at Bourewa, occupied first in 3050 cal BP (1100 BCE), where people lived in houses on stilt platforms built along the axis of a subtidal sand barrier; on one side was a broad coral reef, on the other a partly‐enclosed tidal inlet. There is no evidence that the Bourewa settlers practised horticulture or agriculture at this time, their subsistence being predominantly marine foraging. After some 300 years of following this subsistence strategy, the inhabitants of Bourewa responded to sea‐level fall and the arrival of cultivars (of taro and yam) by including horticulture. As sea level fell further, a total of 550 mm during the Lapita era, the tidal inlet dried up and marine‐food resources diminished to a point where the natural environment of the Rove Peninsula could no longer sustain its Lapita inhabitants. All Lapita sites in the area were abandoned about 2500 cal BP (550 BCE), at the same time as the Lapita culture, marked by the end of dentate‐pottery manufacture, came to an end in Fiji.
Chiari‐like malformation in the Griffon Bruxellois
Authors: Rusbridge C. , Knowler S. P. , Pieterse L. , McFadyen A. K.
Published: August 2009

Objectives: This study describes Chiari‐like malformation and syringomyelia in the Griffon Bruxellois and establishes if skull radiographs are useful for disease prediction.

Methods: Magnetic resonance imaging from 56 Griffon Bruxellois dogs was assessed for Chiari‐like malformation and cerebrospinal fluid pathway abnormalities. Skull radiographs were obtained in 33 dogs. Two rostrocaudal and two ventrodorsal measurements were made, and ratios of one length to another were compared.

Results: In this selected sample, 60·7 per cent had Chiari‐like malformation. Syringomyelia occurred with and without Chiari‐like malformation (37·5 and 8·9 per cent study population, respectively). The radiographic study demonstrated that one measurement ratio could be used to predict Chiari‐like malformation (sensitivity of 87 per cent and specificity of 78 per cent) and that there were significant interaction factors between sex and syringomyelia for two measurement ratios.

Clinical Significance: The study suggests that Chiari‐like malformation is characterised by a shortening of the basicranium and supra‐occipital bone with a compensatory lengthening of the cranial vault, especially the parietal bone. We described a simple radiographic technique, which may be useful as a screening test until a more definite genetic test for Chiari‐like malformation is available.
Barbiturate intoxication in two dogs confirmed by toxicological urinalysis
Authors: Brauer C. , Tipold A. , Desel H. , Stein V. M.
Published: August 2009

Two dogs were presented within 24 hours to the Department of Small Animal Medicine and Surgery at the University of Veterinary Medicine Hannover for investigation of the sudden onset of neurological abnormalities following a walk in the same park. One dog was observed ingesting a piece of meat. Analysis of urine by gas chromatography‐mass spectrometry from each of the dogs identified the presence of barbiturates. Both dogs recovered with supportive treatment. This is the first report to describe the use of toxicological urinalysis with gas chromatography‐mass spectrometry for the diagnosis of barbiturate intoxication in dogs.
Unusually rapid growth and adult stature in an American hairless terrier puppy
Authors: Lyon S. D. , Toll J. , Schermerhorn T.
Published: August 2009

A puppy was evaluated for rapid growth and large stature. Extensive diagnostic evaluation suggested a growth hormone independent disorder. As the sole detected abnormality was elevated leptin concentration, an obesity syndrome causing leptin resistance was speculated to explain the puppy's condition but was not confirmed. Except for large body size, the puppy remained clinically normal.
Association between cervical and intracranial dimensions and syringomyelia in the cavalier King Charles spaniel
Authors: Carruthers H. , Rusbridge C. , Dubé M.‐P. , Holmes M. , Jeffery N.
Published: August 2009

Objectives: To investigate the possible association between caudal fossa area and cervical vertebral dimensions and the presence of syringomyelia in cavalier King Charles spaniels.

Methods: From magnetic resonance imaging scans of 78 cavalier King Charles spaniels, measurements were made of the widest vertical spinal width at C1/C2, C2, C2/C3 and C3; angulation of the C2/C3 spine; and estimated caudal fossa area. A correlation between these measurements and syringomyelia was sought.

Results: A total of 59 dogs with and 19 without syringomyelia were compared. Older dogs had a significantly higher incidence of syringo‐myelia. No difference in incidence was noted between genders. There was no significant difference in vertebral canal width at C1/C2 and C2, or angulation of C2/C3 between syringomyelia and non‐syringomyelia groups. The width of the canal at C2/C3 and C3 was significantly increased in syringomyelia dogs. There was no significant difference in the caudal fossa area between groups.

Clinical Significance: Although syringomyelia was shown to be more prevalent in older dogs, the age beyond which dogs were considered at greater risk was not deducible from the dataset. The association identified between wider spinal canal at C3, and C2/C3 and syringomyelia presence is of questionable clinical significance, as the difference between syringomyelia and non‐syringomyelia groups is too small to be measured in a clinical setting.
A secure Aberdeen knot: in vitro assessment of knot security in plasma and fat
Authors: Schaaf O. , Glyde M. , Day R. E.
Published: August 2009

Objectives: To determine the minimum number of throws/turns to form a secure Aberdeen knot and the maximum ear slippage for these knots using three metric polydioxanone coated in fat or plasma. To compare plasma and novel canine liquefied fat as suture coating mediums for in vitro knot security testing.

Methods: Throws/turns were incrementally added until a secure knot was found for plasma and fat. Knots were tensioned until failure and remaining ear length measured. A secure knot was defined as ear slippage 3 mm or less in 20 consecutively tested knots. Ear slippages were statistically analysed.

Results: Minimum secure configuration was a 3+1 knot in plasma and fat, and its ear slipped a maximum of 2 mm in plasma and 2·5 mm in fat. A secure 4+1 knot had a maximum ear slippage of 0·5 mm, which was significantly less than that of the 3+1 knot (P<0·0001). Fat coating suture significantly decreases in vitro knot security compared with plasma (P=0·0035).

Clinical Significance: The novel fat coating medium should be considered when testing in vitro knot security as it simulates a clinical knot tying environment. A 4+1 Aberdeen knot with a 3 mm ear is recommended to tie a secure Aberdeen knot in any body fluid environment.
BSAVA Manual of Canine and Feline Emergency and Critical Care
Authors: Goggs Robert
Published: August 2009

BSAVA Manual of Canine and Feline Emergency and Critical Care

Edited by Lesley G. King and Amanda K. Boag

Published by the British Small Animal Veterinary Association, 2007, 2nd edition, paperback, 380 pages, Price £85.00, ISBN‐13: 978‐0905214993
Developmental Pathways of Emotion Regulation in Childhood: A Neuropsychological Perspective
Authors: Woltering Steven , Lewis Marc D.
Published: August 2009

This article presents a model featuring two types of emotion regulation—reactive and deliberate—and discusses the developmental trajectory of both types. We argue that the later‐developing capacity for deliberate control builds on and coevolves with earlier‐developing reactive control. Findings from the field of developmental neuroscience are mapped onto this model. The focus is on specific neural “hubs,” such as the anterior cingulate cortex and the orbitofrontal cortex, which serve as epicenters for the coupling of cortical and subcortical processes. We propose that an increasing coordination between brain regions during emotional situations subserves more effective and efficient regulation with development. This framework can be used to explain different developmental pathways of regulatory styles that can, for example, lead to aggressive versus anxious modes of emotion regulation. The implications of this framework can help guide educational policy by supporting prevention and intervention strategies for children exhibiting difficulties with emotion regulation.
Stem cell factor rescues tyrosinase expression and pigmentation in discreet anatomic locations in albino mice
Authors: Vanover Jillian C , Spry Malinda L , Hamilton Laura , Wakamatsu Kazumasa , Ito Shosuke , D’Orazio John A
Published: August 2009

The K14‐SCF transgenic murine model of variant pigmentation is based on epidermal expression of stem cell factor (SCF) on the C57BL/6J background. In this system, constitutive expression of SCF by epidermal keratinocytes results in retention of melanocytes in the interfollicular basal layer and pigmentation of the epidermis itself. Here, we extend this animal model by developing a compound mutant transgenic amelanotic animal defective at both the melanocortin 1 receptor (Mc1r) and tyrosinase (Tyr) loci. In the presence of K14‐Scf, tyrosinase‐mutant animals (previously thought incapable of synthesizing melanin) exhibited progressive robust epidermal pigmentation with age in the ears and tails. Furthermore, K14‐SCF Tyrc2j/c2j animals demonstrated tyrosinase expression and enzymatic activity, suggesting that the c2j Tyr defect can be rescued in part by SCF in the ears and tail. Lastly, UV sensitivity of K14‐Scf congenic animals depended mainly on the amount of eumelanin present in the skin. These findings suggest that c‐kit signaling can overcome the c2j Tyr mutation in the ears and tails of aging animals and that UV resistance depends on accumulation of epidermal eumelanin.
On Explanatory Relata in Singular Causal Explanation
Authors: ZELEŇÁK EUGEN
Published: August 2009

Explanation is usually taken to be a relation between certain entities. The aim of this paper is to discuss what entities are suitable as explanatory relata of singular causal explanations, i.e., explanations concerning singular causality relating particular events or other appropriate entities. I outline three different positions. The purely causal approach stipulates that the same entities that are related in the singular causal relation are also linked by the explanatory relation. This position, however, has a problem to distinguish between causation and explanation, two distinct relations allegedly obtaining between the same entities. The linguistic approach states that explanatory relata are linguistic entities of some sort, e.g., statements, propositions, etc. There are various versions of this position. I deal with two of them and try to show that they are unsatisfactory because they transform explanation into some other type of relation. On the first version, explanation is very close to interpretation or clarification of intension and on the second version it seems to be indistinguishable from an evidential relation or justification. I consider these transformations in understanding explanation unnecessary, and consequently reject linguistic views of explanatory relata. The most promising proposal concerning explanatory relata seems to be the mixed view, according to which propositions explain events or other fitting extra‐linguistic entities.
Am I a Series?
Authors: JOHANSSON JENS
Published: August 2009

Scott Campbell has recently defended the psychological approach to personal identity over time by arguing that a person is literally a series of mental events. Rejecting four‐dimensionalism about the persistence of physical objects, Campbell regards constitutionalism as the main rival version of the psychological approach. He argues that his “series view” has two clear advantages over constitutionalism: it avoids the “two thinkers” objection and it allows a person to change bodies. In addition, Campbell suggests a reply to the objection, often raised against views such as his, that thoughts must be distinct from their thinker. In this paper, I argue that Campbell's responses to the “two thinkers” and the “thoughts/thinker” objections are unsuccessful. Furthermore, his reply to the latter leads to four‐dimensionalism of the kind he wanted to avoid – and this view too allows a person to change bodies. Moreover, I argue that it speaks against the series view that generalised versions of it fare much more poorly than do generalised versions of constitutionalism and four‐dimensionalism.
Multiple Realizations, Diverse Implementations and Antireductionism
Authors: KIM SUNGSU
Published: August 2009

It has been debated what implications multiple realizability has for reductionism. I claim that more explicit attention needs to be paid to the distinction between multiple realizations of kinds and diverse implementations of laws. In this paper, I distinguish two different theses on the relations between multiple realization and diverse implementation: one thesis states that multiple realizations imply diverse implementations and the other states the converse. I claim that although antireductionism might turn out to be false if the first thesis is accepted, this “realization‐based” antireductionism is not the only option for antireductionism. For the antireductionists who accept the second thesis, multiple realizations only provide evidence for diverse implementations. I defend this “implementation‐based” antireductionism again Shapiro's dilemma. I argue that one horn of the dilemma does not pose any problem and that the other horn simply begs the question.
Moore‐Paradoxicality and the Principle of Charity
Authors: BRUECKNER ANTHONY
Published: August 2009

In a recent article in Theoria, Hamid Vahid offered an explanation of the phenomenon of Moore‐paradoxicality which employed Davidson's Principle of Charity regarding radical interpretation. I argue here that Vahid's explanation fails.
Differences in Medical Treatment of Chronic Coronary Heart Disease Patients According to Medical Specialities
Authors: Cordero Alberto , Bertomeu‐Martínez Vicente , Mazón Pilar , Quiles Juan , Aznar Joaquín , Bueno Héctor
Published: August 2009

Coronary heart disease (CHD) patients are currently attended by many different medical specialities. CHD patients must achieve the highest grade of treatment implementation and risk factors control. The aims were to describe differences in medical treatment of CHD according to the medical specialities. For this purpose we conducted an observational, cross‐sectional, and multicenter study of CHD patients attended by internal medicine (IM), outpatient clinic cardiologist (OCC), hospital cardiologist (HC), and general practitioners (PC). Burden of noncardiac diseases was evaluated by the Charlson index. Joint prescription of antiplatelets, statins, beta‐blockade agents and blockade of the renin–angiotensin system by angiotensin‐converting enzyme inhibitors (ACEI) or angiotensin receptors blockers (ARB) was considered optimal medical treatment (OMT). A total of 2987 patients, mean age 67.4 (11.5) years and 71.5% males, were analyzed. Patients visited by IM physicians had slightly higher mean age and higher prevalence of hypertension, diabetes, and noncardiac diseases (median Charlson index 3.0, 1.0–5.0, vs. 2.0, 1.0–4.0, of total sample). OMT was prescribed in 25.9% (95% CI 25.6–26.2) of the patients and was statistically more frequently carried out by HC (32.1%) and OCC (29.0%) compared to IM (22.0%) and PC practitioners (21.5%). Multivariate analysis showed an independent association between OMT prescription and HC (OR 1.42; 95% CI 1.08–1.87) or OCC (OR 1.31; 95% CI 1.04–1.67); this association remained after including the Charlson index. Noncardiac diseases are the main clinical differences in CHD patients visited by different medical specialist although it does not explain the higher prescription of OMT by cardiologist.
NEEDLE‐STICK INJURY: A NOVEL INTERVENTION TO REDUCE THE OCCUPATIONAL HEALTH AND SAFETY RISK IN THE HAEMODIALYSIS SETTING
Authors: Chow Josephine , Rayment Glenda , Wong Jeff , Jefferys Andrew , Suranyi Michael
Published: August 2009

Needle‐stick injury (NSI) is a major occupational health and safety issue facing healthcare professionals. The administration of erythropoiesis‐stimulating agents (ESA) in haemodialysis patients represents a major cause for injections. The purpose of this initiative was to familiarise nursing staff with needle‐free administration of an ESA in haemodialysis patients to reduce the risk of NSI.

Epoetin beta comes in a commercial presentation with a detached needle. Epoetin beta was administered to 10 haemodialysis patients via the venous bubble trap short line of the haemodialysis circuit. An audit was conducted that included a retrospective assessment of NSI for the previous six months; and a prospective assessment for eight weeks to assess whether there is a nursing staff preference for needle‐free administration of ESA.

There were no reports of NSI in the needle‐free group. Haemoglobin levels were maintained. Ninety‐one percent of the nursing staff preferred needle‐free administration of ESA. In conclusion, the commercial presentation of epoetin beta with the detached needle presents an opportunity to reduce the potential risk of NSI in haemodialysis units.
CROHN'S DISEASE AND SECONDARY AMYLOIDOSIS: EARLY COMPLICATION? A CASE REPORT AND REVIEW OF THE LITERATURE
Authors: Basturk Taner , Ozagarı Aysım , Ozturk Tulım , Kusaslan Ramazan , Unsal Abdulkadır
Published: August 2009

Secondary amyloidosis is a rare but serious complication of inflammatory bowel disease (IBD), generally seen in Crohn's disease. At least 1% of patients with Crohn's disease develop amyloidosis. In the literature, the time lapse between the onset of Crohn's disease and the diagnosis of amyloidosis has been reported to range from one to 21 years. In most patients, protein‐uria heralded the onset of renal involvement from amyloid and occurred from three to 15 years after Crohn's disease diagnosis. In this case, we estimate secondary amyloidosis occurred before Crohn's disease or early Crohn's disease complication, based on the fact that hypoalbuminaemia and proteinuria was detected approximately one year after the start of gastrointestinal complaints.
CE: Continuing Education Article MANAGEMENT OF CO‐MORBID DISEASES IN A PATIENT WITH ESTABLISHED RENAL FAILURE
Authors: Chamney Melissa , Pugh‐Clarke Karen , Kafkia Theodora
Published: August 2009

This follows on from an article relating to chronic kidney disease (CKD) and co‐morbidities. Not only do these co‐morbid diseases cause problems to patients with CKD, they continue to impact upon them when they develop established renal failure (ERF). Various co‐morbid conditions can affect the patient including diabetes, hypertension, anaemia and cardiovascular issues. As nephrology nurses we play a fundamental role in patient education, monitoring and management of these factors.
THE BURNOUT AND EXHAUSTION LEVELS OF NURSES WORKING IN HAEMODIALYSIS UNITS
Authors: Kapucu Sevgi Sun , Akkuş Yeliz , Akdemir Nuran , Karacan Yasemin
Published: August 2009

Aim: The aim of the study was to determine the burnout and exhaustion levers of nurses working in haemodialysis units.

Method: The study was a cross‐sectional and descriptive one. A total of 95 nurses working at the 17 dialysis centres in the centre of the Ankara Province were included. The data were collected using a questionnaire defining the socioeconomic characteristics of the nurses and the Maslach Burnout Inventory (MBI) and evaluated using the Mann‐Whitney U test.

Results: Haemodialysis nurses’ emotional burnout score was 16.03 ± 6.28, the depersonalisation score 4.72 ± 3.20 and the personal accomplishment score 20.97 ± 4.61. Their emotional burnout and personal accomplishment level was significantly higher in those considering leaving the profession, nurses who did not find the profession suitable and those working in units where no precautions were taken against infectious disease (p < 0.05).

Conclusion: It may be suggested that taking precautions at units, providing better working conditions, defining the duties of nurses and providing further dialysis education for nurses may decrease burnout rates.
EVALUATION OF PSYCHOLOGICAL OUTCOMES FOLLOWING THE INTERVENTION ‘TEACHING GROUP’: STUDY ON PREDIALYSIS PATIENTS
Authors: Vilaplana Josep Maria Gutiérrez , Zampieron Alessandra , Craver Lourdes , Buja Alessandra
Published: August 2009

Goals: Aims of the study were to evaluate the effects of the intervention ‘Group education’ (NIC 5604) on patients’ coping, fear control, anxiety and the association between demographic and clinical variables with the outcomes.

Materials and Methods: We studied all predialysis patients treated, at Lleida University Hospital, from 1 January 2007 till 31 March 2008, who received the total intervention for six months.

Results: There were 41 patients, 33 male and 8 female. They had a mean age of 60.56 years (SD 13.96); 66% declared family support. Forty‐one percent had a low educational level. The Charlson Comorbidity test showed a mean of 5.07 (SD 1.77). All patients were independent, using the Karnofsky scale and Barthel index. Patients reported a significant improvement in all the outcomes evaluated (anxiety, coping and fear response). Logistic regression showed that the reduction in anxiety and the improved nursing outcomes were not related to demographic and clinical variables.

Conclusion: The group educational programme was effective on the defined psychological outcomes in predialysis patients. Hence, it should be available for all clients.
Outcome of Revision Total Elbow Replacement using the Acclaim Prosthesis
Authors: Hearnden Anthony J. , Desai Aravind S. , Harrison John W. , Dramis Asterios , Hayton Michael J. , Trail Ian A. , Stanley John K.
Published: August 2009

Background

This was a retrospective study presenting our results and survivorship of the Acclaim total elbow when used as a revision implant.

Methods

Between May 2001 and July 2005, 29 revision elbow replacements were carried out on 28 patients in our institution. Five were redo revisions and one received the fourth sequential implant. A variety of implants were removed for aseptic loosening (17), periprosthetic fracture (7), dislocation (3) and infection (2). Two patients had died and one was unavailable for follow-up.

Results

At a mean follow-up of 50 months (12 to 80 months) pain, functional assessment scores and radiographs were assessed and a Kaplan-Meier survival curve created. Symptoms were reliably relieved with 72% reporting no pain. Mean flexion was 128° with loss of full extension of 34°. Complications were noted in six cases of which three patients underwent further surgery. None of the 29 revisions has been re-revised till date.

Conclusion

The medium term results for this implant suggest it is an effective revision prosthesis.
The Qγ component of intra‐membrane charge movement is present in mammalian muscle fibres, but suppressed in the absence of S100A1
Authors: Prosser Benjamin L. , Hernández‐Ochoa Erick O. , Zimmer Danna B. , Schneider Martin F.
Published: August 2009

S100A1 is a Ca2+ binding protein that modulates excitation–contraction (EC) coupling in skeletal and cardiac muscle. S100A1 competes with calmodulin for binding to the skeletal muscle SR Ca2+ release channel (the ryanodine receptor type 1, RyR1) at a site that also interacts with the C‐terminal tail of the voltage sensor of EC coupling, the dihydropyridine receptor. Ablation of S100A1 leads to delayed and decreased action potential evoked Ca2+ transients, possibly linked to altered voltage sensor activation. Here we investigate the effects of S100A1 on voltage sensor activation in skeletal muscle utilizing whole‐cell patch clamp electrophysiology to record intra‐membrane charge movement currents in isolated flexor digitorum brevis (FDB) muscle fibres from wild‐type and S100A1 knock‐out (KO) mice. In contrast to recent reports, we found that FDB fibres exhibit two distinct components of intra‐membrane charge movement, an initial rapid component (Qβ), and a delayed, steeply voltage dependent ‘hump’ component (Qγ) previously recorded primarily in amphibian but not mammalian fibres. Surprisingly, we found that Qγ was selectively suppressed in S100A1 KO fibres, while the Qβ component of charge movement was unaffected. This result was specific to S100A1 and not a compensatory result of genetic manipulation, as transient intracellular application of S100A1 restored Qγ. Furthermore, we found that exposure to the RyR1 inhibitor dantrolene suppressed a similar component of charge movement in FDB fibres. These results shed light on voltage sensor activation in mammalian muscle, and support S100A1 as a positive regulator of the voltage sensor and Ca2+ release channel in skeletal muscle EC coupling.
Simultaneous recording of intramembrane charge movement components and calcium release in wild‐type and S100A1−/−muscle fibres
Authors: Prosser Benjamin L. , Hernández‐Ochoa Erick O. , Zimmer Danna B. , Schneider Martin F.
Published: August 2009

In the preceding paper, we reported that flexor digitorum brevis (FDB) muscle fibres from S100A1 knock‐out (KO) mice exhibit a selective suppression of the delayed, steeply voltage‐dependent component of intra‐membrane charge movement current termedQγ. Here, we use 50 μmof the Ca2+indicator fluo‐4 in the whole cell patch clamp pipette, in addition to 20 mmEGTA and other constituents included for the charge movement studies, and calculate the SR Ca2+release flux from the fluo‐4 signals during voltage clamp depolarizations. Ca2+release flux is decreased in amplitude by the same fraction at all voltages in fibres from S100A1 KO mice compared to fibres from wild‐type (WT) littermates, but unchanged in time course at each pulse membrane potential. There is a strong correlation between the time course and magnitude of release flux and the development ofQγ. The decreased Ca2+release in KO fibres is likely to account for the suppression ofQγin these fibres. Consistent with this interpretation, 4‐chloro‐m‐cresol (4–CMC; 100 μm) increases the rate of Ca2+release and restoresQγat intermediate depolarizations in fibres from KO mice, but does not increase Ca2+release or restoreQγat large depolarizations. Our findings are consistent with similar activation kinetics for SR Ca2+channels in both WT and KO fibres, but decreased Ca2+release in the KO fibres possibly due to shorter SR channel open times. The decreased Ca2+release at each voltage is insufficient to activateQγin fibres lacking S100A1.
Up‐regulation of GLT‐1 severely impairs LTD at mossy fibre–CA3 synapses
Authors: Omrani Azar , Melone Marcello , Bellesi Michele , Safiulina Victoria , Aida Tomomi , Tanaka Kohishi , Cherubini Enrico , Conti Fiorenzo
Published: August 2009

Glutamate transporters are responsible for clearing synaptically released glutamate from the extracellular space. By this action, they maintain low levels of ambient glutamate, thus preventing excitotoxic damage, and contribute to shaping synaptic currents. We show that up‐regulation of the glutamate transporter GLT‐1 by ceftriaxone severely impaired mGluR‐dependent long‐term depression (LTD), induced at rat mossy fibre (MF)–CA3 synapses by repetitive stimulation of afferent fibres. This effect involved GLT‐1, since LTD was rescued by the selective GLT‐1 antagonist dihydrokainate (DHK). DHK per se produced a modest decrease in fEPSP amplitude that rapidly regained control levels after DHK wash out. Moreover, the degree of fEPSP inhibition induced by the low‐affinity glutamate receptor antagonist γ‐DGG was similar during basal synaptic transmission but not during LTD, indicating that in ceftriaxone‐treated rats LTD induction did not alter synaptic glutamate transient concentration. Furthermore, ceftriaxone‐induced GLT‐1 up‐regulation significantly reduced the magnitude of LTP at MF–CA3 synapses but not at Schaffer collateral–CA1 synapses. Postembedding immunogold studies in rats showed an increased density of gold particles coding for GLT‐1a in astrocytic processes and in mossy fibre terminals; in the latter, gold particles were located near and within the active zones. In both CEF‐treated and untreated GLT‐1 KO mice used for verifying the specificity of immunostaining, the density of gold particles in MF terminals was comparable to background levels. The enhanced expression of GLT‐1 at release sites may prevent activation of presynaptic receptors, thus revealing a novel mechanism by which GLT‐1 regulates synaptic plasticity in the hippocampus.
Identification of Inhibitors of Yellow Fever Virus Replication Using a Replicon-Based High-Throughput Assay
Authors: Patkar Chinmay G. , Larsen Martha , Owston Michael , Smith Janet L. , Kuhn Richard J.
Published: August 2009

Flaviviruses cause severe disease in humans and are a public health priority worldwide. However, no effective therapies or drugs are commercially available yet. Several flavivirus replicon-based assays amenable to high-throughput screening of inhibitors have been reported recently. We developed and performed a replicon-based high-throughput assay for screening small-molecule inhibitors of yellow fever virus (YFV) replication. This assay utilized packaged pseudoinfectious particles containing a YFV replicon that expresses
Renilla
luciferase in a replication-dependent manner. Several small-molecule compounds with inhibitory activity at micromolar concentrations were identified in the high-throughput screen. These compounds were subsequently tested for their inhibitory activities against YFV replication and propagation in low-throughput assays. Furthermore, YFV mutants that escaped inhibition by two of the compounds were isolated, and in both cases, the mutations were mapped to the NS4B coding region, suggesting a novel inhibitory target for these compounds. This study opens up new avenues for pursuing the nonenzymatic nonstructural proteins as targets for antivirals against YFV and other flaviviruses.
The Proteasome Inhibitor Epoxomicin Has Potent
Plasmodium falciparum
Gametocytocidal Activity
Authors: Czesny Beata , Goshu Samrawit , Cook James L. , Williamson Kim C.
Published: August 2009

Malaria continues to be a major global health problem, but only a limited arsenal of effective drugs is available. None of the antimalarial compounds commonly used clinically kill mature gametocytes, which is the form of the parasite that is responsible for malaria transmission. The parasite that causes the most virulent human malaria,
Plasmodium falciparum
, has a 48-h asexual cycle, while complete sexual differentiation takes 10 to 12 days. Once mature, stage V gametocytes circulate in the peripheral blood and can be transmitted for more than a week. Consequently, if chemotherapy does not eliminate gametocytes, an individual continues to be infectious for several weeks after the clearance of asexual parasites. The work reported here demonstrates that nanomolar concentrations of the proteasome inhibitor epoxomicin effectively kill all stages of intraerythrocytic parasites but do not affect the viability of human or mouse cell lines. Twenty-four hours after treatment with 100 nM epoxomicin, the total parasitemia decreased by 78%, asexual parasites decreased by 86%, and gametocytes decreased by 77%. Seventy-two hours after treatment, no viable parasites remained in the 100 or 10 nM treatment group. Epoxomicin also blocked oocyst production in the mosquito midgut. In contrast, the cysteine protease inhibitors epoxysuccinyl-
l
-leucylamido-3-methyl-butane ethyl ester and
N
-acetyl-
l
-leucyl-
l
-leucyl-
l
-methioninal blocked hemoglobin digestion in early gametocytes but had no effect on later stages. Moreover, once the cysteine protease inhibitor was removed, sexual differentiation resumed. These findings provide strong support for the further development of proteasome inhibitors as antimalaria agents that are effective against asexual, sexual, and mosquito midgut stages of
P. falciparum
.
Borrelia burgdorferi
Resistance to a Major Skin Antimicrobial Peptide Is Independent of Outer Surface Lipoprotein Content
Authors: Sarkar Amit , Tilly Kit , Stewart Philip , Bestor Aaron , Battisti James M. , Rosa Patricia A.
Published: August 2009

We hypothesize a potential role for
Borrelia burgdorferi
OspC in innate immune evasion at the initial stage of mammalian infection. We demonstrate that
B. burgdorferi
is resistant to high levels (>200 μg/ml) of cathelicidin and that this antimicrobial peptide exhibits limited binding to the spirochetal outer membrane, irrespective of OspC or other abundant surface lipoproteins. We conclude that the essential role of OspC is unrelated to resistance to this component of innate immunity.
Large-Scale Sequence Analysis of M Gene of Influenza A Viruses from Different Species: Mechanisms for Emergence and Spread of Amantadine Resistance
Authors: Furuse Yuki , Suzuki Akira , Oshitani Hitoshi
Published: August 2009

Influenza A virus infects many species, and amantadine is used as an antiviral agent. Recently, a substantial increase in amantadine-resistant strains has been reported, most of which have a substitution at amino acid position 31 in the M2 gene. Understanding the mechanism responsible for the emergence and spread of antiviral resistance is important for developing a treatment protocol for seasonal influenza and for deciding on a policy for antiviral stockpiling for pandemic influenza. The present study was conducted to identify the existence of drug pressure on the emergence and spread of amantadine-resistant influenza A viruses. We analyzed data on more than 5,000 virus sequences and constructed a phylogenetic tree to calculate selective pressures on sites in the M2 gene associated with amantadine resistance (positions 26, 27, 30, and 31) among different hosts. The phylogenetic tree revealed that the emergence and spread of the drug-resistant M gene in different hosts and subtypes were independent and not through reassortment. For human influenza virus, positive selection was detected only at position 27. Selective pressures on the sites were not always higher for human influenza virus than for viruses of other hosts. Additionally, selective pressure on position 31 did not increase after the introduction of amantadine. Although there is a possibility of drug pressure on human influenza virus, we could not find positive pressure on position 31. Because the recent rapid increase in drug-resistant virus is associated with the substitution at position 31, the resistance may not be related to drug use.
High-Throughput Identification of New Protective Antigens from a
Yersinia pestis
Live Vaccine by Enzyme-Linked Immunospot Assay
Authors: Li Bei , Zhou Lei , Guo JingYu , Wang Xiaoyi , Ni Bin , Ke Yuehua , Zhu Ziwen , Guo Zhaobiao , Yang Ruifu
Published: August 2009

Yersinia pestis
, the plague pathogen, is a facultative intracellular bacterium. Cellular immunity plays important roles in defense against infections. The identification of T-cell targets is critical for the development of effective vaccines against intracellular bacteria; however, the function of cellular immunity in protection from plague was not clearly understood. In this study, 261 genes from
Y. pestis
were selected on the basis of bioinformatics analysis and previous research results for expression in
Escherichia coli
BL21(DE3). After purification, 101 proteins were qualified for examination of their abilities to induce the production of gamma interferon in mice immunized with live vaccine EV76 by enzyme-linked immunospot assay. Thirty-four proteins were found to stimulate strong T-cell responses. The protective efficiencies for 24 of them were preliminarily evaluated using a mouse plague model. In addition to LcrV, nine proteins (YPO0606, YPO1914, YPO0612, YPO3119, YPO3047, YPO1377, YPCD1.05c, YPO0420, and YPO3720) may provide partial protection against challenge with a low dose (20 times the 50% lethal dose [20× LD
50
]) of
Y. pestis
, but only YPO0606 could partially protect mice from infection with
Y. pestis
at a higher challenge dosage (200× LD
50
). These proteins would be the potential components for
Y. pestis
vaccine development.
Use of
Moraxella catarrhalis
Lipooligosaccharide Mutants To Identify Specific Oligosaccharide Epitopes Recognized by Human Serum Antibodies
Authors: Schwingel Johanna M. , Edwards Katie J. , Cox Andrew D. , Masoud Hussein , Richards James C. , St. Michael Frank , Tekwe Carmen D. , Sethi Sanjay , Murphy Timothy F. , Campagnari Anthony A.
Published: August 2009

Moraxella catarrhalis
is a causative agent of otitis media in children and lower respiratory tract infections in adults suffering from chronic obstructive pulmonary disease (COPD). This strict human pathogen continues to be a significant cause of disease in this broad spectrum of patients because there is no available vaccine. Although numerous putative vaccine antigens have been described, little is known about the human immune response to
M. catarrhalis
infection in vivo. Human serum antibodies are directed at a number of surface proteins, and lipooligosaccharides (LOS) and detoxified LOS may be an effective immunogen in mice. In this study, we used a specific LOS-based enzyme-linked immunosorbent assay (ELISA), containing the three major
M. catarrhalis
serotypes together with a complete series of truncated LOS mutants, to detect the development of new antibodies to specific regions of the oligosaccharide molecule. We compared serum samples from COPD patients who had recently cleared an
M. catarrhalis
infection to serum samples collected prior to their infection. Variability in the antibody response to LOS was observed, as some patients developed serotype-specific antibodies, others developed antibodies to the LOS of each serotype, others developed broadly cross-reactive antibodies, and some did not develop new antibodies. These newly developed human antibodies are directed at both side chains and core structures in the LOS molecule. This LOS-based ELISA can be used to dissect the human antibody response to both internal and external carbohydrate epitopes, thus providing a better understanding of the humoral immune response to
M. catarrhalis
LOS epitopes developed during natural infection.
Establishment of SystemicBrucella melitensisInfection through the Digestive Tract Requires Urease, the Type IV Secretion System, and Lipopolysaccharide O Antigen
Authors: Paixão Tatiane A. , Roux Christelle M. , den Hartigh Andreas B. , Sankaran-Walters Sumathi , Dandekar Satya , Santos Renato L. , Tsolis Renée M.
Published: August 2009

Human brucellosis is caused mainly byBrucella melitensis, which is often acquired by ingesting contaminated goat or sheep milk and cheese. Bacterial factors required for food-borne infection of humans byB. melitensisare poorly understood. In this study, a mouse model of oral infection was characterized to assess the roles of urease, the VirB type IV secretion system, and lipopolysaccharide for establishing infection through the digestive tract.B. melitensisstrain 16M was consistently recovered from the mesenteric lymph node (MLN), spleen, and liver beginning at 3 or 7 day postinfection (dpi). In the gut, persistence of the inoculum was observed up to 21 dpi. No inflammatory lesions were observed in the ileum or colon during infection. Mutant strains lacking theureABCgenes of theure1operon,virB2, orpmmencoding phosphomannomutase were constructed and compared to the wild-type strain for infectivity through the digestive tract. Mutants lacking thevirB2andpmmgenes were attenuated in the spleen (P< 0.05) and MLN (P< 0.001), respectively. The wild-type and mutant strains had similar levels of resistance to low pH and 5 or 10% bile, suggesting that the reduced colonization of mutants was not the result of reduced resistance to acid pH or bile salts. In an in vitro lymphoepithelial cell (M-cell) model,B. melitensistransited rapidly through polarized enterocyte monolayers containing M-like cells; however, transit through monolayers containing only enterocytes was reduced or absent. These results indicate thatB. melitensisis able to spread systemically from the digestive tract after infection, most likely through M cells of the mucosa-associated lymphoid tissue.
The NanI and NanJ Sialidases of
Clostridium perfringens
Are Not Essential for Virulence
Authors: Chiarezza Martina , Lyras Dena , Pidot Sacha J. , Flores-Díaz Marietta , Awad Milena M. , Kennedy Catherine L. , Cordner Leanne M. , Phumoonna Tongted , Poon Rachael , Hughes Meredith L. , Emmins John J. , Alape-Girón Alberto , Rood Julian I.
Published: August 2009

The essential toxin in
Clostridium perfringens
-mediated gas gangrene or clostridial myonecrosis is alpha-toxin, although other toxins and extracellular enzymes may also be involved. In many bacterial pathogens extracellular sialidases are important virulence factors, and it has been suggested that sialidases may play a role in gas gangrene.
C. perfringens
strains have combinations of three different sialidase genes, two of which,
nanI and nanJ
, encode secreted sialidases. The
nanI
and
nanJ
genes were insertionally inactivated by homologous recombination in derivatives of sequenced strain 13 and were shown to encode two functional secreted sialidases, NanI and NanJ. Analysis of these derivatives showed that NanI was the major sialidase in this organism. Mutation of
nanI
resulted in loss of most of the secreted sialidase activity, and the residual activity was eliminated by subsequent mutation of the
nanJ
gene. Only a slight reduction in the total sialidase activity was observed in a
nanJ
mutant. Cytotoxicity assays using the B16 melanoma cell line showed that supernatants containing NanI or overexpressing NanJ enhanced alpha-toxin-mediated cytotoxicity. Finally, the ability of
nanI
,
nanJ
, and
nanIJ
mutants to cause disease was assessed in a mouse myonecrosis model. No attenuation of virulence was observed for any of these strains, providing evidence that neither the NanI sialidase nor the NanJ sialidase is essential for virulence.
The Trehalose Synthesis Pathway Is an Integral Part of the Virulence Composite for
Cryptococcus gattii
Authors: Ngamskulrungroj Popchai , Himmelreich Uwe , Breger Julia A. , Wilson Christabel , Chayakulkeeree Methee , Krockenberger Mark B. , Malik Richard , Daniel Heide-Marie , Toffaletti Dena , Djordjevic Julianne T. , Mylonakis Eleftherios , Meyer Wieland , Perfect John R.
Published: August 2009

The trehalose pathway is essential for stress tolerance and virulence in fungi. We investigated the importance of this pathway for virulence of the pathogenic yeast
Cryptococcus gattii
using the highly virulent Vancouver Island, Canada, outbreak strain R265. Three genes putatively involved in trehalose biosynthesis,
TPS1
(trehalose-6-phosphate [T6P] synthase) and
TPS2
(T6P phosphatase), and degradation,
NTH1
(neutral trehalose), were deleted in this strain, creating the R265
tps1
Δ, R265
tps2
Δ, and R265
nth1
Δ mutants. As in
Cryptococcus neoformans
, cellular trehalose was reduced in the R265
tps1
Δ and R265
tps2
Δ mutants, which could not grow and died, respectively, at 37°C on yeast extract-peptone-dextrose agar, suggesting that T6P accumulation in R265
tps2
Δ is directly toxic. Characterizations of the cryptococcal hexokinases and trehalose mutants support their linkage to the control of glycolysis in this species. However, unlike
C. neoformans
, the
C. gattii
R265
tps1
Δ mutant demonstrated, in addition, defects in melanin and capsule production, supporting an influence of T6P on these virulence pathways. Attenuated virulence of the R265
tps1
Δ mutant was not due solely to its 37°C growth defect, as shown in worm studies and confirmed by suppressor mutants. Furthermore, an intact trehalose pathway controls protein secretion, mating, and cell wall integrity in
C. gattii
. Thus, the trehalose synthesis pathway plays a central role in the virulence composites of
C. gattii
through multiple mechanisms. Deletion of
NTH1
had no effect on virulence, but inactivation of the synthesis genes,
TPS1
and
TPS2
, has profound effects on survival of
C. gattii
in the invertebrate and mammalian hosts. These results highlight the central importance of this pathway in the virulence composites of both pathogenic cryptococcal species.