bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD23b Isoform Expression in Human Schistosomiasis Identifies a Novel Subset of Activated B Cells
Authors: Onguru Daniel , Liang YanMei , Elliot Jennifer , Mwinzi Pauline , Ganley-Leal Lisa 
Published: June 2011

ABSTRACTResistance to schistosomiasis is associated with increased levels of serum parasite-specific IgE. IgE exerts its functions through its cellular receptors, FcεRI and FcεRII/CD23; however, its functional significance in humans requires further characterization. We previously reported that increased levels of CD23+B cells correlate with resistance to schistosomiasis in hyperexposed populations and sought to define their potential function and relationship with IgE. We found that CD23+B cells are a heterogeneous cell population with functional and phenotypic differences. Circulating CD23+B cells are uniquely activated in schistosomiasis and express the CD23b isoform and CXCR5, the homing receptor for lymphoid follicles. High CXCR5 expression by CD23+B cells was associated with the capacity to home to the cognate ligand CXCL13. CD23-bound IgE cross-linking increased surface expression of CXCR5, suggesting that CD23+B cells home directly into the lymphoid follicles upon antigen capture. As human schistosomiasis is an intravascular parasitic infection associated with a high antigenic burden in the blood, circulating CD23+B cells may play a role in the capture and shuttling of antigens directly to splenic follicles, highlighting a new role for circulating B cells. This function likely plays an important role in the development of protective immunity to infection with schistosomes.
Differential Response of the Human Renal Proximal Tubular Epithelial Cell Line HK-2 to Shiga Toxin Types 1 and 2
Authors: Lentz Erin K. , Leyva-Illades Dinorah , Lee Moo-Seung , Cherla Rama P. , Tesh Vernon L. 
Published: June 2011

ABSTRACT

Shiga toxins (Stxs) are expressed by the enteric pathogens
Shigella dysenteriae
serotype 1 and certain serotypes of
Escherichia coli
. Stx-producing bacteria cause bloody diarrhea with the potential to progress to acute renal failure. Stxs are potent protein synthesis inhibitors and are the primary virulence factors responsible for renal damage that may follow diarrheal disease. We explored the use of the immortalized human proximal tubule epithelial cell line HK-2 as an
in vitro
model of Stx-induced renal damage. We showed that these cells express abundant membrane Gb
3
and are differentially susceptible to the cytotoxic action of Stxs, being more sensitive to Shiga toxin type 1 (Stx1) than to Stx2. At early time points (24 h), HK-2 cells were significantly more sensitive to Stxs than Vero cells; however, by 72 h, Vero cell monolayers were completely destroyed while some HK-2 cells survived toxin challenge, suggesting that a subpopulation of HK-2 cells are relatively toxin resistant. Fluorescently labeled Stx1 B subunits localized to both lysosomal and endoplasmic reticulum (ER) compartments in HK-2 cells, suggesting that differences in intracellular trafficking may play a role in susceptibility to Stx-mediated cytotoxicity. Although proinflammatory cytokines were not upregulated by toxin challenge, Stx2 selectively induced the expression of two chemokines, macrophage inflammatory protein-1α (MIP-1α) and MIP-1β. Stx1 and Stx2 differentially activated components of the ER stress response in HK-2 cells. Finally, we demonstrated significant poly(ADP-ribose) polymerase (PARP) cleavage after exposure to Stx1 or Stx2. However, procaspase 3 cleavage was undetectable, suggesting that HK-2 cells may undergo apoptosis in response to Stxs in a caspase 3-independent manner.
Analysis of the Networks Controlling the Antimicrobial-Peptide-Dependent Induction of Klebsiella pneumoniae Virulence Factors
Authors: Llobet Enrique , Campos Miguel A. , Giménez Paloma , Moranta David , Bengoechea José A. 
Published: June 2011

ABSTRACT

Antimicrobial peptides (APs) impose a threat to the survival of pathogens, and it is reasonable to postulate that bacteria have developed strategies to counteract them. Polymyxins are becoming the last resort to treat infections caused by multidrug-resistant Gram-negative bacteria and, similar to APs, they interact with the anionic lipopolysaccharide. Given that polymyxins and APs share the initial target, it is possible that bacterial defense mechanisms against polymyxins will be also effective against host APs. We sought to determine whether exposure to polymyxin will increase
Klebsiella pneumoniae
resistance to host APs. Indeed, exposure of
K. pneumoniae
to polymyxin induces cross-resistance not only to polymyxin itself but also to APs present in the airways. Polymyxin treatment upregulates the expression of the capsule polysaccharide operon and the loci required to modify the lipid A with aminoarabinose and palmitate with a concomitant increase in capsule and lipid A species containing such modifications. Moreover, these surface changes contribute to APs resistance and also to polymyxin-induced cross-resistance to APs. Bacterial loads of lipid A mutants in trachea and lungs of intranasally infected mice were lower than those of wild-type strain. PhoPQ, PmrAB, and the Rcs system govern polymyxin-induced transcriptional changes, and there is a cross talk between PhoPQ and the Rcs system. Our findings support the notion that
Klebsiella
activates a defense program against APs that is controlled by three signaling systems. Therapeutic strategies directed to prevent the activation of this program could be a new approach worth exploring to facilitate the clearance of the pathogen from the airways.
Long Polar Fimbriae of Enterohemorrhagic Escherichia coli O157:H7 Bind to Extracellular Matrix Proteins
Authors: Farfan Mauricio J. , Cantero Lidia , Vidal Roberto , Botkin Douglas J. , Torres Alfredo G. 
Published: June 2011

ABSTRACT

Adherence to intestinal cells is a key process in infection caused by enterohemorrhagic
Escherichia coli
(EHEC). Several adhesion factors that mediate the binding of EHEC to intestinal cells have been described, but the receptors involved in their recognition are not fully characterized. Extracellular matrix (ECM) proteins might act as receptors involved in the recognition of enteric pathogens, including EHEC. In this study, we sought to characterize the binding of EHEC O157:H7 to ECM proteins commonly present in the intestine. We found that EHEC prototype strains as well as other clinical isolates adhered more abundantly to surfaces coated with fibronectin, laminin, and collagen IV. Further characterization of this phenotype, by using antiserum raised against the LpfA1 putative major fimbrial subunit and by addition of mannose, showed that a reduced binding of EHEC to ECM proteins was observed in a long polar fimbria (
lpf
) mutant. We also found that the two regulators, H-NS and Ler, had an effect in EHEC Lpf-mediated binding to ECM, supporting the roles of these tightly regulated fimbriae as adherence factors. Purified Lpf major subunit bound to all of the ECM proteins tested. Finally, increased bacterial adherence was observed when T84 cells, preincubated with ECM proteins, were infected with EHEC. Taken together, these findings suggest that the interaction of Lpf and ECM proteins contributes to the EHEC colonization of the gastrointestinal tract.
Protective Efficacy and Safety of Brucella melitensis 16MΔmucRagainst Intraperitoneal and Aerosol Challenge in BALB/c Mice
Authors: Arenas-Gamboa A. M. , Rice-Ficht A. C. , Kahl-McDonagh M. M. , Ficht T. A. 
Published: June 2011

ABSTRACTBrucellosis is a zoonosis of nearly worldwide distribution. Vaccination against this pathogen is an important control strategy to prevent the disease. Currently licensed vaccine strains used in animals are unacceptable for human use due to undesirable side effects and modest protection. Substantial progress has been made during the past 10 years toward the development of improved vaccines for brucellosis. In part, this has been achieved by the identification and characterization of live attenuated mutants that are safer in the host but still can stimulate an adequate immune response. In the present study, the identification and characterization of themucRmutant (BMEI 1364) as a vaccine candidate for brucellosis was conducted. BALB/c mice were vaccinated intraperitoneally at a dose of 105CFU with the mutant to evaluate safety and protective efficacy against intraperitoneal and aerosol challenge. All animals vaccinated with the vaccine candidate demonstrated a statistically significant degree of protection against both intraperitoneal and aerosol challenge. Safety was revealed by the absence ofBrucellaassociated pathological changes, including splenomegaly, hepatomegaly, or granulomatous disease. These results suggest that the 16MΔmucRvaccine is safe, elicits a strong protective immunity, and should be considered as a promising vaccine candidate for human use.
Context-Dependent Activation Kinetics Elicited by Soluble versus Outer Membrane Vesicle-Associated Heat-Labile Enterotoxin
Authors: Chutkan Halima , Kuehn Meta J. 
Published: June 2011

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is the leading cause of traveler's diarrhea and children's diarrhea worldwide. Among its virulence factors, ETEC produces heat-labile enterotoxin (LT). Most secreted LT is associated with outer membrane vesicles that are rich in lipopolysaccharide. The majority of prior studies have focused on soluble LT purified from ETEC periplasm. We investigated the hypothesis that the extracellular vesicle context of toxin presentation might be important in eliciting immune responses. We compared the polarized epithelial cell responses to apically applied soluble LT and LT-containing vesicles (LT+vesicles) as well as controls using a catalytically inactive mutant of LT and vesicles lacking LT. Although vesicle treatments with no or catalytically inactive LT induced a modest amount of interleukin-6 (IL-6), samples containing catalytically active LT elicited higher levels. A combination of soluble LT and LT-deficient vesicles induced significantly higher IL-6 levels than either LT or LT+vesicles alone. The responses to LT+vesicles were found to be independent of the canonical LT pathway, because the inhibition of cyclic AMP response element (CRE)-binding protein (CREB) phosphorylation did not lead to a decrease in cytokine gene expression levels. Furthermore, soluble LT caused earlier phosphorylation of CREB and activation of CRE compared with LT+vesicles. Soluble LT also led to the activation of activator protein 1, whereas LT+vesicle IL-6 responses appeared to be mediated by NF-κB. In summary, the results demonstrate that soluble LT and vesicle-bound LT elicit ultimately similar cytokine responses through distinct different activation pathways.
Elbow flexor and extensor muscle weakness in lateral epicondylalgia
Authors: Coombes Brooke K , Bisset Leanne , Vicenzino Bill 
Published: June 2011

ObjectiveTo evaluate whether deficits of elbow flexor and extensor muscle strength exist in lateral epicondylalgia (LE) in comparison with a healthy control population.DesignCross-sectional study.Participants150 participants with unilateral LE were compared with 54 healthy control participants.Main outcome measuresMaximal isometric elbow flexion and extension strength were measured bilaterally using a purpose-built standing frame such that gripping was avoided.ResultsThe authors found significant side differences in elbow extensor (−6.54 N, 95% CI −11.43 to −1.65, p=0.008, standardised mean difference (SMD) −0.45) and flexor muscle strength (−11.26 N, 95% CI −19.59 to −2.94, p=0.009, SMD −0.46) between LE and control groups. Within the LE group, only elbow extensor muscle strength deficits between sides was significant (affected–unaffected: −2.94 N, 95% CI −5.44 to −0.44).ConclusionSmall significant deficits of elbow extensor and flexor muscle strength exist in the affected arm of unilateral LE in comparison with healthy controls. Notably, comparing elbow strength between the affected and unaffected sides in unilateral epicondylalgia is likely to underestimate these deficits.Trial RegistrationAustralian New Zealand Clinical Trials Register ACTRN12609000051246.
Social and cultural influences on tobacco-related health disparities among South Asians in the USA
Authors: Mukherjea Arnab , Morgan Patricia A , Snowden Lonnie R , Ling Pamela M , Ivey Susan L 
Published: June 2011

ObjectiveTo explore and understand key cultural contexts of tobacco use among South Asian communities in the USA.DesignFocus groups, with homogeneous compositions of gender, generational status and length of time in the USA, were conducted in two distinct South Asian ethnic enclaves. Focus group findings were triangulated with observational data regarding the availability of culturally specific tobacco from commercial ethnic outlets and cultural events.SubjectsRespondents included 88 men and women of South Asian descent, aged 18–65 years, immigrant and native born, representing diversity of religion, socioeconomic status and region of origin, with the use of at least one culturally specific tobacco product in previous 24 months.ResultsA large number of culturally specific products were commonly used by community members. Knowledge of product-specific health risks was lacking or inaccurate. Many culturally specific tobacco products were considered to have beneficial properties. South Asian tobacco items were used to preserve cultural traditions and express ethnic identity in a new dominant culture. The social and cultural values ascribed to use helped distinguish community members from mainstream society and from other minority populations.ConclusionsMany cultural factors govern tobacco use among diverse global populations. Especially for migrants with a common regional origin, the role of ethnic identity may strongly influence culturally specific tobacco patterns. Qualitative inquiry helps elucidate such culturally framed behaviour in culturally diverse populations. These cultural contexts should be integrated into research and practice. Understanding multidimensional factors influencing non-traditional tobacco use is essential to ensure that comprehensive tobacco control strategies address tobacco-related disparities.
Structural and stratigraphic evolution of the Savu Basin, Indonesia
Authors: Rigg James W. D. , Hall Robert 
Published: June 2011

Abstract
The Savu Basin is located in the Sunda–Banda fore-arc at the position of change from oceanic subduction to continent–arc collision. It narrows eastward and is bounded to the west by the island of Sumba that obliquely crosses the fore-arc. New seismic data and published geological observations are used to interpret Australia–Sundaland convergence history. We suggest the basin is underlain by continental crust and was close to sea level in the Early Miocene. Normal faulting in the Middle Miocene and rapid subsidence to several kilometres was driven by subduction rollback. Arc-derived volcaniclastic turbidites were transported ESE, parallel to the Sumba Ridge, and then NE. The ridge was elevated as the Australian continental margin arrived at the Banda Trench, causing debris flows and turbidites to flow northwards into the basin which is little deformed except for tilting and slumping. South of the ridge fore-arc sediments and Australian sedimentary cover were incorporated in a large accretionary complex formed as continental crust was thrust beneath the fore-arc. This is bounded to the north by the Savu and Roti Thrusts and to the south by a trough connecting the Java Trench and Timor Trough which formed by south-directed thrusting and loading.
Tectonic post-collision processes in Timor
Authors: Audley-Charles M. G. 
Published: June 2011

Abstract

Indian Ocean crust subducted northwards at the Banda Trench from about 12 to 4 Ma. The Australian continental margin collided with the Asian fore-arc at about 4 Ma. Gradually the Banda Trench was transformed into the fold and thrust mountains of Timor Island. Tectonic collision processes developed when all ocean crust had been subducted and Australian continental crust was refused entry to the subduction path below the Asian fore-arc. The Banda Trench was then gradually converted into a Tectonic Collision Zone (TCZ) progressively filled by two highly deformed Australian continental upper crust mega-sequences. Slowing subduction of Australian sub-crustal lithosphere after
c
. 2.5 Ma led to uplift of the TCZ that raised Timor 3 km above sea level. Asian Banda fore-arc deformation is linked to
c
. 30 km southeastwards rollback of the subducting Australian mantle lithosphere. Two Asian fore-arc nappes were thrust southwards from the Banda fore-arc onto the older of two highly deformed Australian continental margin upper crust mega-sequences. The Wetar Suture was created as a thrust at the base of Australian partially detached continental lower crust propagated into the Asian fore-arc. Re-interpretation of BIRPS seismic and gravity data for the Timor region supports this collision model.
Physical oceanography of the present day Indonesian Throughflow
Authors: Tillinger Debra 
Published: June 2011

Abstract

The Indonesian Throughflow (ITF) transfers
c
. 15 Sv (1 Sv=10
6
m
3
s
−1
) of relatively cool, fresh water from the tropical Pacific Ocean to the tropical Indian Ocean. Additionally, the ITF is a key interocean component of the global ocean warm water route, which returns water from the Pacific Ocean to the Atlantic Ocean to close the loop of the thermohaline overturning circulation associated with North Atlantic Deep Water. That flow consequently freshens the Indian Ocean and transports heat between basins. The ITF can also be described by the island rule, which relates the winds over the entire South Pacific Ocean to the magnitude of the ITF. El Niño-Southern Oscillation (ENSO) dominates the regional variability in the Pacific Ocean and exerts a strong control over the variability of ITF transport. The Indian Ocean responds to the ENSO signal as well, but is also influenced by the Indian Ocean Dipole, a climate phenomenon that may act independently of ENSO to affect the ITF.
The impact of ocean gateways on ENSO variability in the Miocene
Authors: Von Der Heydt Anna S. , Dijkstra Henk A. 
Published: June 2011

Abstract
The existence of El Niño/Southern Oscillation (ENSO) variability in past climates is still debated. Based on evidence from geological records indicating a different long-term mean climate in the tropical Pacific, a permanent El Niño state has been hyothesized to exist prior to the Plio-Pleistocene transition. However, model studies of past climate and geological records suggest that ENSO variability has existed on Earth as far back as in the Eocene and the Miocene. In the early-to-middle Miocene, climate was not only warmer than today, but oceanic gateways such as the Indonesian Passage and the Central American Seaway established deep connections between the main ocean basins. Here, we analyse the effect of increased levels of atmospheric greenhouse gases and open tropical gateways on the amplitude, period and pattern of ENSO variability using results of fully coupled climate model simulations. While our model shows only small changes in ENSO variability under increased greenhouse gas levels, it suggests a significantly stronger and less frequent ENSO due to altered oceanic gateways. In particular, a deeper and more open Indonesian Passage does not prevent a Western Pacific warm pool from developing, but it allows the warm pool to shift into the Indian Ocean.
Subsidence and uplift by slab-related mantle dynamics: a driving mechanism for the Late Cretaceous and Cenozoic evolution of continental SE Asia?
Authors: Clements Benjamin , Burgess Peter M. , Hall Robert , Cottam Michael A. 
Published: June 2011

Abstract

Continental SE Asia is the site of an extensive Cretaceous–Paleocene regional unconformity that extends from Indochina to Java, covering an area of
c
. 5 600 000 km
2
. The unconformity has previously been related to microcontinental collision at the Java margin that halted subduction of Tethyan oceanic lithosphere in the Late Cretaceous. However, given the disparity in size between the accreted continental fragments and area of the unconformity, together with lack of evidence for requisite crustal shortening and thickening, the unconformity is unlikely to have resulted from collisional tectonics alone. Instead, mapping of the spatial extent of the mid–Late Cretaceous subduction zone and the Cretaceous–Paleocene unconformity suggests that the unconformity could be a consequence of subduction-driven mantle processes. Cessation of subduction, descent of a northward dipping slab into the mantle, and consequent uplift and denudation of a sediment-filled Late Jurassic and Early Cretaceous dynamic topographic low help explain the extent and timing of the unconformity. Sediments started to accumulate above the unconformity from the Middle Eocene when subduction recommenced beneath Sundaland.
Basement character and basin formation in Gorontalo Bay, Sulawesi, Indonesia: new observations from the Togian Islands
Authors: Cottam M. A. , Hall R. , Forster M. A. , Boudagher-Fadel M. K. 
Published: June 2011

Abstract
We present a new stratigraphy for the Togian Islands, Sulawesi, and interpret the age, character and evolution of Gorontalo Bay. At its western end the bay is underlain by continental crust. The central part is underlain by Eocene to Miocene oceanic and arc rocks, although the area south of the Togian Islands could have continental crust of the Banggai-Sula microcontinent thrust beneath this and the East Arm ophiolite. Gorontalo Bay was not a significant deep bathymetric feature before the Miocene. Field relationships indicate a latest Miocene to Pliocene age for inception of the basin. Medium-K to shoshonitic volcanism in the Togian Islands is not due to subduction but reflects crustal thinning and extension in the Pliocene and Pleistocene, causing the underlying mantle to rise, decompress and melt. Extension is continuing today and is probably the cause of volcanism at Una-Una. Volcanic activity migrated west with time and volcanic products have been offset by dextral strike-slip displacement along the Balantak Fault. Extension and subsidence was driven by rollback of the subduction hinge at the North Sulawesi Trench with a possible contribution due to flow of the lower crust.
Large-scale integrated photonics for high-performance interconnects
Authors: Beausoleil Raymond G. 
Published: June 2011

Moore's Law has set great expectations that the performance of information technology will improve exponentially until at least the end of this decade. Although the physics of silicon transistors alone might allow these expectations to be met, the physics of the long metal wires that cross and connect packages almost certainly will not. Global-level interconnects incorporating large-scale integrated photonics fabricated on the same platform as silicon microelectronics hold the promise of revolutionizing computing by enabling parallel many-core and network switch architectures that combine unprecedented performance and ease of use with affordable power consumption.
Over the last decade, remarkable progress has been made in research on low-power silicon photonic devices for interconnect applications, and CMOS-compatible fabrication technologies promise a “Moore's Law for photonics” that could completely change the economics of integrated optics. In this survey, photonic technologies amenable to large-scale CMOS integration are reviewed from the perspective of high-performance interconnects operating over distance scales of 1mm to 100m. An overview of the requirements placed on integrated optical devices by a variety of modern computer applications leads to discussions of active and passive photonic components designed to generate, guide, filter, modulate, and detect light in the telecommunication bands. Critical challenges and prospects for large-scale integration are evaluated with an emphasis on silicon-on-insulator as a platform for photonics.