bluuebunny/crossref_metadata_2025 huggingface dataset:
The physiology of rodent beta‐cells in pancreas slices
Authors: Rupnik M.
Published: November 2008

Beta‐cells in pancreatic islets form complex syncytia. Sufficient cell‐to‐cell electrical coupling seems to ensure coordinated depolarization pattern and insulin release that can be further modulated by rich innervation. The complex structure and coordinated action develop after birth during fast proliferation of the endocrine tissue. These emergent properties can be lost due to various reasons later in life and can lead to glucose intolerance and diabetes mellitus. Pancreas slice is a novel method of choice to study the physiology of beta‐cells still embedded in their normal cellulo‐social context. I present major advantages, list drawbacks and provide an overview on recent advances in our understanding of the physiology of beta‐cells using the pancreas slice approach.
Decoding epithelial signals: critical role for the epidermal growth factor receptor in controlling intestinal transport function
Authors: McCole D. F. , Barrett K. E.
Published: November 2008

The intestinal epithelium engages in bidirectional transport of fluid and electrolytes to subserve the physiological processes of nutrient digestion and absorption, as well as the elimination of wastes, without excessive losses of bodily fluids that would lead to dehydration. The overall processes of intestinal ion transport, which in turn drive the secretion or absorption of water, are accordingly carefully regulated. We and others have identified the epidermal growth factor receptor (EGFr) as a critical regulator of mammalian intestinal ion transport. In this article, we focus on our studies that have uncovered the intricate signalling mechanisms downstream of EGFr that regulate both chloride secretion and sodium absorption by colonocytes. Emphasis will be placed on the EGFr‐associated regulatory pathways that dictate the precise outcome to receptor activation in response to signals that may seem, on their face, to be quite similar if not identical. The concepts to be discussed underlie the ability of the intestinal epithelium to utilize a limited set of signalling effectors to produce a variety of outcomes suitable for varying physiological and pathophysiological demands. Our findings therefore are relevant not only to basic biological principles, but also may ultimately point to new therapeutic targets in intestinal diseases where ion transport is abnormal.
The lateral intercellular space as osmotic coupling compartment in isotonic transport
Authors: Larsen E. H. , Willumsen N. J. , Møbjerg N. , Sørensen J. N.
Published: November 2008

Solute‐coupled water transport and isotonic transport are basic functions of low‐ and high‐resistance epithelia. These functions are studied with the epithelium bathed on the two sides with physiological saline of similar composition. Hence, at transepithelial equilibrium water enters the epithelial cells from both sides, and with the reflection coefficient of tight junction being larger than that of the interspace basement membrane, all of the water leaves the epithelium through the interspace basement membrane. The common design of transporting epithelia leads to the theory that an osmotic coupling of water absorption to ion flow is energized by lateral Na+/K+ pumps. We show that the theory accounts quantitatively for steady‐ and time dependent states of solute‐coupled fluid uptake by toad skin epithelium. Our experimental results exclude definitively three alternative theories of epithelial solute–water coupling: stoichiometric coupling at the molecular level by transport proteins like SGLT1, electro‐osmosis and a ‘junctional fluid transfer mechanism’. Convection‐diffusion out of the lateral space constitutes the fundamental problem of isotonic transport by making the emerging fluid hypertonic relative to the fluid in the lateral intercellular space. In the Na+ recirculation theory the ‘surplus of solutes’ is returned to the lateral space via the cells energized by the lateral Na+/K+ pumps. We show that this theory accounts quantitatively for isotonic and hypotonic transport at transepithelial osmotic equilibrium as observed in toad skin epithelium in vitro. Our conclusions are further developed for discussing their application to solute–solvent coupling in other vertebrate epithelia such as small intestine, proximal tubule of glomerular kidney and gallbladder. Evidence is discussed that the Na+ recirculation theory is not irreconcilable with the wide range of metabolic cost of Na+ transport observed in fluid‐transporting epithelia.
Downstream from calcium signalling: mitochondria, vacuoles and pancreatic acinar cell damage
Authors: Voronina S. , Sherwood M. , Barrow S. , Dolman N. , Conant A. , Tepikin A.
Published: November 2008

Ca2+ is one of the most ancient and ubiquitous second messengers. Highly polarized pancreatic acinar cells serve as an important cellular model for studies of Ca2+ signalling and homeostasis. Downstream effects of Ca2+ signalling have been and continue to be an important research avenue. The primary functions regulated by Ca2+ in pancreatic acinar cells – exocytotic secretion and fluid secretion – have been defined and extensively characterized in the second part of the last century. The role of cytosolic Ca2+ in cellular pathology and the related question of the interplay between Ca2+ signalling and bioenergetics are important current research lines in our and other laboratories. Recent findings in these interwoven research areas are discussed in the current review.
Applicatives
Authors: McGinnis Martha
Published: November 2008

An applicative is a syntactic element adding an extra object to a clause. In some cases, the direct and applied objects are generated within a small clause; in others, the applied object is generated outside the main verb phrase. Symmetric applicatives allow either object to move to the subject position of a passive clause; asymmetric applicatives allow only one object to move. Within Minimalist theory, syntactic movement is constrained by the Minimal Link Condition (MLC). In the simplest case, the MLC allows only the highest argument to move to subject position. However, the lower object can do so if the higher object is ineligible for movement, or if the lower one moves over it via a syntactic escape hatch. A surprising interaction of binding and movement provides independent evidence for this analysis. A new phase‐based approach seeks to illuminate the nature of syntactic domains by connecting movement in applicatives with their semantic and phonological properties.
Can Language Politics Ensure Languages Survival? Evidence from Italy
Authors: Perta Carmela
Published: November 2008

In light of the minority language revitalization trend, which has spread throughout Europe, encouraged by International and European legislation, at the end of the last century, an Italian law was approved to give a national framework to minority language preservation and renaissance. The status and prestige of minority languages thus appeared to be strengthened, though several theoretical and practical problems continue to impede national implementation of the law. Some of these problems – the different language minorities present in Italy, the linguistic variety that should be used in public settings and the nature of the language that is the object of the national language policy – are examined in this article. The purpose of this article is to consider the pros and cons of Italian language policies and politics through case studies representative of Italian sociolinguistic diversity, thus highlighting the roadblocks to protecting minority languages.
The Effect of Class Size Reduction on Foreign Language Learning: A Case Study1
Authors: Yi Heejong
Published: November 2008

The effect of class size reduction (CSR) has been a frequent topic in educational policy over the past decades. Although previous studies yield inconclusive results, the expectation has been that implementing CSR would improve students’ academic achievement. This article studies the effects of CSR in adult foreign language classrooms at a single institution. Language proficiency data from students learning Modern Standard Arabic, Chinese, or Korean in a class of reduced size (5–6 students per classroom) are compared to those in the standard size classroom for this institution (9–10 students per classroom). At the midpoint in the course, the effects of CSR are evident in the areas of pronunciation and communicative skills. At the end of the course, the students in a CSR classroom reach higher proficiency in reading, listening, and speaking.
Discourse Impairments Following Right Hemisphere Brain Damage: A Critical Review
Authors: Johns Clinton L. , Tooley Kristen M. , Traxler Matthew J.
Published: November 2008

Right hemisphere brain damage (RHD) rarely causes aphasias marked by clear and widespread failures of comprehension or extreme difficulty producing fluent speech. Nonetheless, subtle language comprehension deficits can occur following unilateral RHD. In this article, we review the empirical record on discourse function following right hemisphere damage, as well as relevant work on non‐brain damaged individuals that focuses on right hemisphere function. The review is divided into four sections that focus on discourse processing, inferencing, humor, and non‐literal language. While the exact role that the right hemisphere plays in language processing, and the exact way that the two cerebral hemispheres coordinate their linguistic processes are still open to debate, our review suggests that the right hemisphere plays a critical role in managing inferred or implied information by maintaining relevant information and/or suppressing irrelevant information. Deficits in one or both of these mechanisms may account for discourse deficits following RHD.
Why All Counter‐Evidence to the Critical Period Hypothesis in Second Language Acquisition Is not Equal or Problematic
Authors: Rothman Jason
Published: November 2008

That adult and child language acquisitions differ in route and outcome is observable. Notwithstanding, there is controversy as to what this observation means for the Critical Period Hypothesis’ (CPH) application to adult second language acquisition (SLA). As most versions of the CPH applied to SLA claim that differences result from maturational effects on in‐born linguistic mechanisms, the CPH has many implications that are amendable to empirical investigation. To date, there is no shortage of literature claiming that the CPH applies or does not apply to normal adult SLA. Herein, I provide an epistemological discussion on the conceptual usefulness of the CPH in SLA (cf. Singleton 2005) coupled with a review of Long's (2005) evaluation of much available relevant research. Crucially, I review studies that Long did not consider and conclude differently that there is no critical/sensitive period for L2 syntactic and semantic acquisition.
Stanislas Dehaene’s Les neurones de la lecture
Authors: Battro Antonio M.
Published: November 2008

ABSTRACT— Stanislas Dehaene has published a remarkable book on the neurons of reading. It is a comprehensive description of the main issues related to the “paradox of reading”: how humans process linguistic information using the visual brain path while the brain has not evolved in the short period of time since the invention of writing. The article presents a powerful “neuronal recycling” hypothesis to explain the remarkable properties of our cultural neuroplasticity. Scientists and educators will find a trove of information and deep discussions regarding the universal challenge of teaching and learning to read.
Quandaries for Neuroeducators
Authors: Gardner Howard
Published: November 2008

ABSTRACT— Ethical quandaries abound in the emerging field of neuroeducation. Concepts and findings from the GoodWork® Project may help neuroeducators deal ethically with these quandaries. In particular, ethical work is easier to carry out when all stakeholders concur on the means and goals of the profession. Similarly, when professionals wear only one occupational hat, ethical work is more readily achieved than when the professionals need to reconcile two conflicting hats. Such quandaries need not be tackled alone. An organization like the International Mind, Brain, and Education Society is a promising venue for discussing and perhaps resolving these quandaries.
Performance on Middle School Geometry Problems With Geometry Clues Matched to Three Different Cognitive Styles
Authors: Anderson Karen L. , Casey M. Beth , Thompson William L. , Burrage Marie S. , Pezaris Elizabeth , Kosslyn Stephen M.
Published: November 2008

ABSTRACT— This study investigated the relationship between 3 ability‐based cognitive styles (verbal deductive, spatial imagery, and object imagery) and performance on geometry problems that provided different types of clues. The purpose was to determine whether students with a specific cognitive style outperformed other students, when the geometry problems provided clues compatible with their cognitive style. Students were identified as having a particular cognitive style when they scored equal to or above the median on the measure assessing this ability. A geometry test was developed in which each problem could be solved on the basis of verbal reasoning clues (matching verbal deductive cognitive style), mental rotation clues (matching spatial imagery cognitive style), or shape memory clues (matching object imagery cognitive style). Straightforward cognitive style–clue‐compatibility relationships were not supported. Instead, for the geometry problems with either mental rotation or shape memory clues, students with a combination of both verbal and spatial cognitive styles tended to do the best. For the problems with verbal reasoning clues, students with either a verbal or a spatial cognitive style did well, with each cognitive style contributing separately to success. Thus, both spatial imagery and verbal deductive cognitive styles were important for solving geometry problems, whereas object imagery was not. For girls, a spatial imagery cognitive style was advantageous for geometry problem solving, regardless of type of clues provided.
United Kingdom myeloma forum position statement on the use of lenalidomide in multiple myeloma
Authors: DAVIES F. , MORRIS C. , BIRD J. , COOK G. , WILLIAMS C. , TIGHE J. , CAVENAGH J. , BEHRENS J. , SCHEY S. , MORGAN G. ,   On Behalf Of The United Kingdom Myeloma Forum
Published: November 2008

Lenalidomide is an immunomodulatory drug, which has anti‐myeloma activity in vitro. Phase II clinical trials have demonstrated lenalidomide in combination with dexamethasone is effective for the treatment of both relapsed refractory myeloma and newly diagnosed patients. Two large phase III studies comparing lenalidomide and dexamethasone to dexamethasone alone in relapsed patients showed superiority in response, progression free and overall survival. It is administered orally for 21 days in a 28 day cycle. Side effects are manageable and include neutropenia and venous thrombotic events. It is currently approved, in combination with dexamethasone, for the treatment of multiple myeloma patients who have received at least one prior therapy. Studies in front line patients and with other drug combinations are ongoing. Given the strength of this data the UK Myeloma Forum believe that lenalidomide in combination with dexamethasone should be available for prescription by UK haematologists according to its licensed indication in patients with relapsed myeloma.
Distal Embolic Protection During Renal Artery Stenting: Impact on Hypertensive Patients With Renal Dysfunction
Authors: Singer Gregory M. , Setaro John F. , Curtis Jeptha P. , Remetz Michael S.
Published: November 2008

Distal embolic protection (DEP) may prevent embolization of atherosclerotic debris during renal artery stenting. The authors retrospectively identified 48 hypertensive patients with chronic kidney disease (CKD) who underwent renal artery stenting between 2002 and 2005 and compared stenting alone (n=17) to stenting/DEP (n=31). Blood pressure (BP) and estimated glomerular filtration rate (eGFR) (mL/min/1.73m2) at baseline at 6 and 12 months were compared. Overall, eGFR improved by 4.7 (P=.005) at 6 months and 3.8 (P=.003) at 12 months compared with baseline. Comparing stent to stent/DEP patients, eGFR improvement did not differ at 6 months (7.6 vs 2.9; P=.15) or at 12 months (4.4 vs 3.5; P=.74). Systolic BP reduction was similar between stent and stent/DEP patients at 6 months (−9 vs −14 mm Hg; P=.59) and at 12 months (−18 vs −16 mm Hg; P=.89). Renal artery stenting improved eGFR and systolic BP in patients with hypertension and CKD; however, DEP did not enhance these effects.
Serum Phosphate, Blood Pressure, and the Metabolic Syndrome—20‐Year Follow‐Up of Middle‐Aged Men
Authors: Gudmundsdottir Helga , Strand Arne H. , Kjeldsen Sverre E. , Høieggen Aud , Os Ingrid
Published: November 2008

The authors investigated the relationship between serum phosphate (S‐phosphate) and the metabolic syndrome in a group of middle‐aged hypertensive and normotensive men during 20‐year follow‐up. Fifty‐six men participated. Of the original 34 normotensive men, hypertension developed in 17. In the group as a whole and in those in whom hypertension developed, there was a significant negative relationship between S‐phosphate at baseline and mean blood pressure (MBP) at follow‐up. A significant relationship was observed between S‐phosphate at baseline and components of the metabolic syndrome in the group as a whole, in individuals with hypertension, and in individuals with the lowest S‐phosphate levels at follow‐up. S‐phosphate at baseline predicted MBP 20 years later in a group of hypertensive and normotensive men. When grouped according to the number of components of the metabolic syndrome, individuals with the lowest serum phosphate levels had the highest number of risk factors. These findings may suggest a role of low S‐phosphate in the development of hypertension and the metabolic syndrome.
Management of High Blood Pressure in Clinical Practice: Perceptible Qualitative Differences in Approaches Utilized by Clinicians
Authors: Nwachuku Chuke E. , Bastien Arnaud , Cutler Jeffrey A. , Grob Glenda M. , Margolis Karen L. , Roccella Edward J. , Pressel Sara , Davis Barry R. , Caso Michael , Sheps Sheldon , Weber Michael
Published: November 2008

The authors recruited a group of physicians from among the investigators participating in the Antihypertensive and Lipid‐Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) with a greater (more successful) or lesser (less successful) proportion of trial patients meeting blood pressure (BP) control goals. The authors utilized qualitative focus group methods to identify similarities and differences in practice behaviors. Successful and less successful physicians had similarities in knowledge and practice behaviors regarding awareness of treatment guidelines, approaches to diagnosis, use of pharmacologic management, and the opinion that systolic BP guidelines should consider a patient’s age. However, there were discernible differences between the two physician groups in their views on doctor‐patient relationships: physicians from the less successful group were more paternalistic with their patients, while physicians from the more successful group were more likely to use a patient‐centered clinical approach to BP awareness and management.
Evaluation and Treatment of Resistant or Difficult‐to‐Control Hypertension
Authors: Wojciechowski David , Papademetriou Vasilios , Faselis Charles , Fletcher Ross
Published: November 2008

An observational study was conducted in 164 patients with resistant or difficult‐to‐control hypertension. Treatment was adjusted to achieve blood pressure recommendations from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Patients were mostly male (95.73%) and African American (86.59%) and had an average age of 63.68 years. Comorbidities included diabetes (42.07%) and chronic kidney disease, with an average estimated glomerular filtration rate of 83.55 mL/min/1.73 m2. At the time of referral, average blood pressure was 160/87 mm Hg. The average number of antihypertensive medications per patient at baseline was 3.43, which increased to 4.06 and 4.18 at 3 and 6 months, respectively (P≤.0008), with about 80% of patients receiving a diuretic prior to intervention. Blood pressure decreased to 135.55/74.55 and 137.62/74.03 mm Hg at 3 and 6 months, respectively (P<.0001). By month 6, the blood pressure goal was reached in 45.10% of patients. At months 3 and 6, 100% of patients were now receiving a diuretic. The average estimated glomerular filtration rate at month 6 was 79.36 mL/min/1.73 m2 (P=NS). Patients referred for resistant or difficult‐to‐control hypertension may be controlled by making targeted adjustments to their medical regimen.
Regular use of non‐steroidal anti‐inflammatory drugs increases the risk of adult‐onset asthma: a population‐based follow‐up study
Authors: Thomsen Simon Francis , Kyvik Kirsten Ohm , Skadhauge Lars Rauff , Steffensen Ida , Backer Vibeke
Published: November 2008

Background:  Little is known about the relation between regular use of non‐steroidal anti‐inflammatory drugs (NSAIDs) and the risk of asthma at the population level. The aim of this study was to examine a possible association between intake of NSAIDs and risk of adult‐onset asthma.

Methods:  Using data from two multidisciplinary postal questionnaire surveys concerning health and lifestyle, we prospectively studied 19 349 adult twins enrolled in the nationwide Danish Twin Registry.

Results:  We found a higher prevalence of new‐onset asthma in subjects who used NSAIDs (other than aspirin) regularly compared with non‐users (7.7% vs 4.3%), OR = 1.87 (1.25–2.81), P = 0.002. The result remained significant after adjusting for sex, age, smoking, BMI, hay fever, eczema and intake of medications other than NSAIDs, OR = 1.90 (1.26–2.85), P = 0.002.

Conclusions:  Regular use of NSAIDs other than aspirin may be a risk factor for adult‐onset asthma. This observation must be accommodated in explanations of the relationship between use of analgesics and risk of asthma.

Please cite this paper as: Thomsen SF, Kyvik KO, Skadhauge LR, Steffensen I and Backer V. Regular use of non‐steroidal anti‐inflammatory drugs increases the risk of adult‐onset asthma: a population‐based follow‐up study. The Clinical Respiratory Journal 2009; 3: 82–84.
Use of heavy silicone oil (Densiron‐68®) in the treatment of persistent macular holes
Authors: Lappas Alexandra , Heinrich Foerster Andreas Michael , Kirchhof Bernd
Published: November 2008

Purpose:  In this retrospective case series, we studied the effect of ‘heavy’ silicone oil on persisting macular holes. Patients with macular holes that failed to close after conventional macular hole surgery were retreated with the longterm internal tamponade Densiron‐68®.

Methods:  Twelve patients with primary macular holes that persisted after pars plana vitrectomy, peeling of the internal limiting membrane and internal gas tamponade with SF6 (sulphur hexafluoride) were retreated with heavy silicone oil, Densiron‐68®, in the University Eye Hospital, Cologne. After 1.5–4 months the Densiron‐68® was removed. Best corrected visual acuity (VA), slit‐lamp examination, binocular fundus examination and optical coherence tomography (OCT) were used for evaluation pre‐ and postoperatively. The follow‐up period was 3–7 months.

Results:  Preoperatively, all patients displayed full‐thickness macular holes, with a mean size of 502.25 μm (± 129.39 μm). Postoperatively, 11 of 12 macular holes were closed. One patient experienced a reopening of the macular hole. Mean VA was 20/250 (1.07 ± 0.22 logMAR) prior to treatment with Densiron‐68® and 20/160 (0.84 ± 0.24 logMAR) postoperatively. Visual acuity increased from baseline in nine patients and decreased in one.

Conclusions:  Retreatment of persisting macular holes with the heavy, longterm tamponade Densiron‐68® resulted in anatomical closure of the hole in 11 of 12 cases. This result was accompanied by a functional improvement in VA in nine of 12 patients.
Investigation of Bartonella henselae in Cats in Ankara, Turkey
Authors: Celebi B. , Kilic S. , Aydin N. , Tarhan G. , Carhan A. , Babur C.
Published: November 2008

The purpose of this study was to determine Bartonella henselae prevalance in cats in Ankara. Whole bloods and sera collected from 256 cats were investigated for the presence feline Bartonella species by culture and sera were tested for the presence of antibodies against B. henselae IgG using immunofluorescence assay. Bartonella species were isolated by blood culture from 24 (9.4%) cats. Bartonella isolates were subjected to restriction fragment length polymorphism (RFLP) by using TaqI and HhaI endonucleases to identify species. Twenty‐one isolates were determined as B. henselae and three of 24 isolates were determined as Bartonella clarridgeiae with RFLP. The bacteraemia prevalence and seroprevalence of B. henselae IgG antibodies in cats was detected as 8.2% and 18.6% respectively. This is the first report on B. henselea and B. clarridgeiae in cats in Turkey.
Experimental Infection withToxocara catiin BALB/c Mice, Migratory Behaviour and Pathological Changes
Authors: Cardillo N. , Rosa A. , Ribicich M. , López C. , Sommerfelt I.
Published: November 2008

Experimental inoculations of 1000Toxocara catilarval eggs were carried out in 18 BALB/c mice. TheT. catieggs used for inoculation were collected from the faeces of naturally infected cats. Euthanasia was performed on two mice on days 1, 2, 3, 4, 5, 6, 14, 21 and 28 post‐inoculation (p.i.). Tissue samples were taken for digestion and histopathology. Larvae were recovered from all infected mice and the average of all larvae recovered was 28.3% (95%; CI: 14.1–42.4). Maximum number was obtained from liver on days 1 and 2 p.i.; from the lung on day 2 p.i. and from the brain on day 28 p.i. In muscle, the recovery was high as from day 3 p.i., with the maximum obtained on day 28 p.i. Superficial foci of congestion and haemorrhage were macroscopically observed in the lungs between days 2 and 5 p.i. and in the brain between days 3 and 6 p.i. Microscopic lesions were observed in the liver between days 2 and 14 p.i., with periportal and subcapsule inflammatory infiltrates. In the lungs, haemorrhages and inflammatory infiltrates can be observed in the alveolar parenchyma, close to bronchioles and large blood vessels. In the brain, congestive areas without inflammatory reactions were seen. In muscle, the presence of inflammatory infiltrates and degenerated muscle can be observed surrounding a parasite larva. These same lesions were observed in myocardium and pericardium. The kidneys were congested with inflammatory infiltrates. The inflammatory cells present in all the tissues studied were lymphocytes, neutrophils and a few eosinophils. Formation of granulomas or signs of larva encapsulation were not observed. The migratory pattern ofT. catilarvae in BALB/c mice and its tendency to become concentrated in the muscle reinforce the importance of the mouse as a paratenic host for the parasite’s cycle in the environment.
Identification of Highly Specific and Cross‐Reactive Antigens of Leishmania Species by Antibodies from Leishmania (Leishmania) chagasi Naturally Infected Dogs
Authors: Vale A. M. , Fujiwara R. T. , Da Silva Neto A. F. , Miret J. A. , Alvarez D. C. C. , Da Silva J. C. F. , Campos‐Neto A. , Reed S. , Mayrink W. , Nascimento E.
Published: November 2008

The Leishmania species present a genetic homology that ranges from 69 to 90%. Because of this homology, heterologous antigens have been used in the immunodiagnosis and vaccine development against Leishmania infections. In the current work, we describe the identification of species‐specific and cross‐reactive antigens among several New World Leishmania species, using symptomatic and asymptomatic naturally Leishmania chagasi‐infected dog sera. Soluble antigens from five strains of New World Leishmania were separated by electrophoresis in SDS‐PAGE and immunoblotted. Different proteins were uniquely recognized in the L. chagasi panel by either symptomatic or asymptomatic dog sera suggesting their use as markers for the progression of disease and diagnosis of the initial (sub‐clinical) phase of the infection. Cross‐reactive antigens were identified using heterologous antigenic panels (L. amazonensis strains PH8 and BH6, L. guyanensis and L. braziliensis). L. guyanensis panel showed the highest cross‐reactivity against L. chagasi specific antibodies, suggesting that proteins from this extract might be suitable for the diagnosis of visceral canine leishmaniasis. Interestingly, the 51 and 97 kDa proteins of Leishmania were widely recognized (77.8% to 100%) among all antigenic panels tested, supporting their potential use for immunodiagnosis. Finally, we identified several leishmanial antigens that might be useful for routine diagnosis and seroepidemiological studies of the visceral canine leishmaniasis.
The Salmonella Enteritidis Lipopolysaccharide Biosynthesis Gene rfbH is Required for Survival in Egg Albumen
Authors: Gantois I. , Ducatelle R. , Pasmans F. , Haesebrouck F. , Van Immerseel F.
Published: November 2008

Salmonella Enteritidis is still a major cause of human food borne infections and can be associated with the consumption of meat and chicken eggs. It is the world’s most common cause of salmonellosis in part because it has the ability to colonize the oviduct and contaminate eggs. It was shown that when stored at room temperature, S. Enteritidis bacteria can multiply extensively in contaminated eggs. Using the in vivo expression technology, it was shown that the rfbH gene, involved in lipopolysaccharide O‐antigen synthesis, is transcriptionally induced during growth in whole eggs at room temperature. A S. Enteritidis ΔrfbH strain was unable to multiply in eggs at room temperature and did not survive in egg white at 42°C. The attenuation was most likely caused by an increased susceptibility of the ΔrfbH mutant to yet undefined antibacterial components of the egg albumen.
Dissociation between sensing and metabolism of glucose in sugar sensing neurones
Authors: Gonzàlez J. Antonio , Reimann Frank , Burdakov Denis
Published: November 2008

Some of the neurones controlling sleep, appetite and hormone release act as specialized detectors of ambient glucose. Their sugar sensing is conventionally thought to involve glucokinase‐dependent metabolism of glucose to ATP, which then alters membrane excitability by modulating ATP‐dependent channels or transporters, such as ATP‐inhibited K+ channels (KATP). However, recent studies also provide examples of both glucose‐excited (GE) and glucose‐inhibited (GI) neurones that sense glucose independently of such metabolic pathways. Two‐thirds of hypothalamic GE neurones in primary cultures are also excited by the non‐metabolizable glucose analogue α‐methylglucopyranoside (α‐MDG), which acts as a substrate for electrogenic (depolarizing) sodium–glucose cotransporter (SGLT). The excitatory responses to both glucose and α‐MDG are abolished by arresting SGLT activity by sodium removal or the SGLT inhibitor phloridzin. Direct depolarization and excitation by glucose‐triggered SGLT activity may ensure that GE neurones continue to sense glucose in ‘high‐energy’ states, when KATP channels are closed. A major class of hypothalamic GI neurones, the orexin/hypocretin cells, also appear to use a non‐metabolic sensing strategy. In these cells, glucose‐induced hyperpolarization and inhibition are unaffected by glucokinase inhibitors such as alloxan, d‐glucosamine, and N‐acetyl‐d‐glucosamine, and mimicked by the non‐metabolizable glucose analogue 2‐deoxyglucose, but not by stimulating intracellular ATP production with lactate. The dissociation between sensing and metabolism of sugar may allow the brain to predict and prevent adverse changes in extracellular glucose levels with minimal impact on the flow of intracellular fuel.
Sec- and Tat-Dependent Translocation of β-Lactamases across theEscherichia coliInner Membrane
Authors: Pradel N. , Delmas J. , Wu L. F. , Santini C. L. , Bonnet R.
Published: November 2008

β-Lactamases represent the major resistance mechanism of gram-negative bacteria against β-lactam antibiotics. The amino acid sequences of these proteins vary widely, but all are located in the periplasm of bacteria. In this study, we investigated the translocation mechanism of representative β-lactamases in anEscherichia colimodel. N-terminal signal sequence analyses, antibiotic activity assay, and direct measurement of translocation of a green fluorescent protein (GFP) reporter fused to β-lactamases revealed that most were exported via the Sec pathway. However, theStenotrophomonas maltophiliaL2 β-lactamase was exported via theE. coliTat translocase, while theS. maltophiliaL1 β-lactamase was Sec dependent. These results show the possible Tat-dependent translocation of β-lactamases in theE. colimodel system. In addition, the mutation of the cytoskeleton-encoding genemreB, which may be involved in the spatial organization of penicillin-binding proteins, decreased the MIC of β-lactams for β-lactamase-producingE. coli. These findings provide new knowledge about β-lactamase translocation, a putative new target for addressing β-lactamase-mediated resistance.
Diverse Cytomegalovirus UL27 Mutations Adapt to Loss of Viral UL97 Kinase Activity under Maribavir
Authors: Chou Sunwen
Published: November 2008

In vitro resistance to maribavir (MBV), a cytomegalovirus UL97 kinase inhibitor currently in clinical trials, is known to result from viral UL97 mutations that confer moderate to high-level resistance and UL27 mutations that confer low-level resistance. To add to the four reported UL27 mutations, cytomegalovirus isolates or strains were propagated under MBV. Four clinical isolates evolved UL27 mutations, which were first detected after 8 to 30 passages under drug selection. In three separate experiments, laboratory strain T2294, which contained an exonuclease mutation, developed UL27 mutations at 10 to 12 passages under MBV. Most of these isolates and strains also developed a UL97 mutation, commonly T409M, before or after the appearance of the UL27 mutation. The passage of two laboratory strains genetically defective in UL97, in the absence of MBV, likewise resulted in UL27 mutations. The nine UL27 mutations observed included multiple instances of point, stop, and frameshift mutations, which were individually transferred to a reference CMV strain and which were shown to confer two- to threefold increases in MBV inhibitory concentrations. In contrast, seven common UL27 amino acid changes found in baseline clinical isolates conferred no MBV resistance. The mutants with UL27 mutations had slightly attenuated growth. The frequent mutation of UL27 suggests that its normal expression is mildly disadvantageous to the virus in the absence of UL97 kinase activity, whether the latter results from MBV inhibition or a genetic defect. Although the function of UL27 is unknown, it does not appear to be a direct antiviral target for MBV.
Immunogenicity and Protective Efficacy of “
Mycobacterium w
” against
Mycobacterium tuberculosis
in Mice Immunized with Live versus Heat-Killed
M. w
by the Aerosol or Parenteral Route
Authors: Gupta Ankan , Geetha Nishamol , Mani Jiju , Upadhyay Pramod , Katoch V. M. , Natrajan M. , Gupta U. D. , Bhaskar Sangeeta
Published: November 2008

As the disease caused by
Mycobacterium tuberculosis
continues to be a burden, there is a concerted effort to find new vaccines to combat this problem. One of the important vaccine strategies is whole bacterial vaccines. This approach relies on multiple antigens and built-in adjuvanticity. Other mycobacterial strains which share cross-reactive antigens with
M. tuberculosis
have been considered as alternatives to
M. bovis
for vaccine use. One such strain, “
Mycobacterium w
”, had been evaluated for its immunomodulatory properties in leprosy. A vaccine against leprosy based on killed
M. w
is approved for human use, where it has resulted in clinical improvement, accelerated bacterial clearance, and increased immune responses to
Mycobacterium leprae
antigens.
M. w
shares antigens not only with
M. leprae
but also with
M. tuberculosis
, and initial studies have shown that vaccination with killed
M. w
induces protection against tuberculosis in
Mycobacterium bovis
BCG responder, as well as BCG nonresponder, strains of mice. Hence, we further studied the protective potential of
M. w
and the underlying immune responses in the mouse model of tuberculosis. We analyzed the protective efficacy of
M. w
immunization in both live and killed forms through the parenteral route and by aerosol immunization, compared with that of BCG. Our findings provide evidence that
M. w
has potential protective efficacy against
M. tuberculosis. M. w
activates macrophage activity, as well as lymphocytes.
M. w
immunization by both the parenteral route and aerosol adminstration gives higher protection than BCG given by the parenteral route in the mouse model of tuberculosis.
Discriminating Virulence Mechanisms amongBacillus anthracisStrains by Using a Murine Subcutaneous Infection Model
Authors: Chand Hitendra S. , Drysdale Melissa , Lovchik Julie , Koehler Theresa M. , Lipscomb Mary F. , Lyons C. Rick
Published: November 2008

Bacillus anthracisstrains harboring virulence plasmid pXO1 that encodes the toxin protein protective antigen (PA), lethal factor, and edema factor and virulence plasmid pXO2 that encodes capsule biosynthetic enzymes exhibit different levels of virulence in certain animal models. In the murine model of pulmonary infection,B. anthracisvirulence was capsule dependent but toxin independent. We examined the role of toxins in subcutaneous (s.c.) infections using two different genetically complete (pXO1+pXO2+) strains ofB. anthracis, strains Ames and UT500. Similar to findings for the pulmonary model, toxin was not required for infection by the Ames strain, because the 50% lethal dose (LD50) of a PA-deficient (PA−) Ames mutant was identical to that of the parent Ames strain. However, PA was required for efficient s.c. infection by the UT500 strain, because the s.c. LD50of a UT500 PA−mutant was 10,000-fold higher than the LD50of the parent UT500 strain. This difference between the Ames strain and the UT500 strain could not be attributed to differences in spore coat properties or the rate of germination, because s.c. inoculation with the capsulated bacillus forms also required toxin synthesis by the UT500 strain to cause lethal infection. The toxin-dependent phenotype of the UT500 strain was host phagocyte dependent, because eliminating Gr-1+phagocytes restored virulence to the UT500 PA−mutant. These experiments demonstrate that the dominant virulence factors used to establish infection byB. anthracisdepend on the route of inoculation and the bacterial strain.
The C-Type Lectin SIGNR1 BindsSchistosoma mansoniAntigens In Vitro, but SIGNR1-Deficient Mice Have Normal Responses during Schistosome Infection
Authors: Saunders Sean P. , Walsh Caitriona M. , Barlow Jillian L. , Mangan Niamh E. , Taylor Philip R. , McKenzie Andrew N. J. , Smith Philip , Fallon Padraic G.
Published: November 2008

The de novo immune response to infectious organisms arises from the innate recognition of pathogen-associated molecular patterns (PAMPs) by the host's pattern recognition receptors (PRRs). As the generation of type 2 cytokine responses by the human trematode parasiteSchistosoma mansoniis glycan mediated, there is a particular potential role for a C-type lectin receptor (CLR) to mediate the innate recognition of schistosome PAMPs. One such CLR, dendritic cell-specific intracellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN; CD209), has been shown to recognize glycans expressed byS. mansonieggs. We show that SIGNR1 (SIGN-related 1; CD209b), a murine homologue of DC-SIGN that is expressed on macrophages, also binds both schistosome-soluble egg antigens and worm antigens in vitro. The generation of schistosome egg-induced pulmonary egg granulomas was not altered in SIGNR1-deficient mice. FollowingS. mansoniinfection, the SIGNR1-deficient mice had an unaltered phenotype with an intact immunological response and no difference in pathology. In this study we demonstrate that although SIGNR1 recognizesS. mansoniantigens in vitro, this CLR is redundant during infection. This study highlights the finding that although there was binding of SIGNR1 to immunogenic factors produced in theS. mansonilife cycle, this recognition does not translate to a functional in vivo role for the PRR during infection.
Sequential B-Cell Epitopes ofBacillus anthracisLethal Factor Bind Lethal Toxin-Neutralizing Antibodies
Authors: Nguyen Melissa L. , Crowe Sherry R. , Kurella Sridevi , Teryzan Simon , Cao Brian , Ballard Jimmy D. , James Judith A. , Farris A. Darise
Published: November 2008

The bipartite anthrax lethal toxin (LeTx) consisting of protective antigen (PA) and lethal factor (LF) is a major virulence factor contributing to death from systemicBacillus anthracisinfection. The current vaccine elicits antibodies directed primarily to PA; however, in experimental settings serologic responses to LF can neutralize LeTx and contribute to protection against infection. The goals of the present study were to identify sequential B-cell epitopes of LF and to determine the capacity of these determinants to bind neutralizing antibodies. Sera of recombinant LF-immunized A/J mice exhibited high titers of immunoglobulin G anti-LF reactivity that neutralized LeTx in vitro 78 days after the final booster immunization and protected the mice from in vivo challenge with 3 50% lethal doses of LeTx. These sera bound multiple discontinuous epitopes, and there were major clusters of reactivity on native LF. Strikingly, all three neutralizing, LF-specific monoclonal antibodies tested bound specific peptide sequences that coincided with sequential epitopes identified in polyclonal antisera from recombinant LF-immunized mice. This study confirms that LF induces high-titer protective antibodies in vitro and in vivo. Moreover, the binding of short LF peptides by LF-specific neutralizing monoclonal antibodies suggests that generation of protective antibodies by peptide vaccination may be feasible for this antigen. This study paves the way for a more effective anthrax vaccine by identifying discontinuous peptide epitopes of LF.
Role of RpoS in the Virulence of
Citrobacter rodentium
Authors: Dong Tao , Coombes Brian K. , Schellhorn Herb E.
Published: November 2008

Citrobacter rodentium
is a mouse enteropathogen that is closely related to
Escherichia coli
and causes severe colonic hyperplasia and bloody diarrhea.
C. rodentium
infection requires expression of genes of the locus of enterocyte effacement (LEE) pathogenicity island, which simulates infection by enteropathogenic
E. coli
and enterohemorrhagic
E. coli
in the human intestine, providing an effective model for studying enteropathogenesis. In this study we investigated the role of RpoS, the stationary phase sigma factor, in virulence in
C. rodentium
. Sequence analysis showed that the
rpoS
gene is highly conserved in
C. rodentium
and
E. coli
, exhibiting 92% identity. RpoS was critical for survival under heat shock conditions and during exposure to H
2
O
2
and positively regulated the expression of catalase KatE (HPII). The development of the RDAR (
r
ed
d
ry
a
nd
r
ough) morphotype, an important virulence trait in
E. coli
, was also mediated by RpoS in
C. rodentium
. Unlike
E. coli, C. rodentium
grew well in the mouse colon, and the wild-type strain colonized significantly better than
rpoS
mutants. However, a mutation in
rpoS
conferred a competitive growth advantage over the wild type both in vitro in Luria-Bertani medium and in vivo in the mouse colon. Survival analysis showed that the virulence of an
rpoS
mutant was attenuated. The expression of genes on the LEE pathogenicity island, which are essential for colonization and virulence, was reduced in the
rpoS
mutant. In conclusion, RpoS is important for the stress response and is required for full virulence in
C. rodentium
.
Direct and Indirect Impairment of Human Dendritic Cell Function by VirulentFrancisella tularensisSchu S4
Authors: Chase Jennifer C. , Celli Jean , Bosio Catharine M.
Published: November 2008

The gram-negative, facultative intracellular bacteriumFrancisella tularensiscauses acute, lethal pneumonic disease following infection with only 10 CFU. The mechanisms used by the bacterium to accomplish this in humans are unknown. Here, we demonstrate that virulent, type AF. tularensisstrain Schu S4 efficiently infects and replicates in human myeloid dendritic cells (DCs). Despite exponential replication over time, Schu S4 failed to stimulate transforming growth factor β, interleukin-10 (IL-10), IL-6, IL-1β, IL-12, tumor necrosis factor alpha, alpha interferon (IFN-α), and IFN-β throughout the course of infection. Schu S4 also suppressed the ability of directly infected DCs to respond to different Toll-like receptor agonists. Furthermore, we also observed functional inhibition of uninfected bystander cells. This inhibition was mediated, in part, by a heat-stable bacterial component. Lipopolysaccharide (LPS) from Schu S4 was present in Schu S4-conditioned medium. However, Schu S4 LPS was weakly inflammatory and failed to induce suppression of DCs at concentrations below 10 μg/ml, and depletion of Schu S4 LPS did not significantly alleviate the inhibitory effect of Schu S4-conditioned medium in uninfected human DCs. Together, these data show that type AF. tularensisinterferes with the ability of a central cell type of the immune system, DCs, to alert the host of infection both intra- and extracellularly. This suggests that immune dysregulation byF. tularensisoperates on a broader and more comprehensive scale than previously appreciated.
β
2
-Microglobulin-Dependent Bacterial Clearance and Survival during Murine
Klebsiella pneumoniae
Bacteremia
Authors: Cogen Anna L. , Moore Thomas A.
Published: November 2008

Klebsiella pneumoniae
is a leading cause of both community-acquired and nosocomial gram-negative bacterial pneumonia. A significant clinical complication of
Klebsiella
pulmonary infections is peripheral blood dissemination, resulting in a systemic infection concurrent with the localized pulmonary infection. We report here on the critical importance of β
2
-microglobulin expression during murine
K. pneumoniae
bacteremia. β
2
-Microglobulin knockout mice displayed significantly increased mortality upon intravenous inoculation that correlated with increased bacterial burden in the blood, liver, and spleen. As β
2
-microglobulin knockout mice lack both CD8
+
T cells and invariant NK T cells, mouse models specifically deficient in either cell population were examined to see if this would account for the increased mortality noted in β
2
-microglobulin knockout mice. Surprisingly, neither CD8 T-cell-deficient (TAP-1 knockout; in vivo anti-CD8 antibody treatment) nor invariant NK (iNK) T-cell-deficient (CD1d knockout, Jα281 knockout) mice were more susceptible to
K. pneumoniae
bacteremia. Combined, these studies clearly indicate the importance of a β
2
-microglobulin-dependent but CD8 T-cell- and iNK T-cell-independent mechanism critical for survival during
K. pneumoniae
bacteremia.