bluuebunny/crossref_metadata_2025 huggingface dataset:
Gangliosides of the retina
Authors: MASSON E , BRETILLON L
Published: December 2011

Purpose Gangliosides are glycosphingolipids particularly abundant in the brain and nervous system, including the retina. A large variety of gangliosides have been described and the profile is specific to the organ or cell type. It has been shown that ganglioside composition of the retina changes during development. Also, it is known that mouse models accumulating specific gangliosides exhibit retinal abnormalities associated with impaired vision. However, the precise role of gangliosides in this organ and its pathologies is still poorly understood. We aimed to determine ganglioside profile of the retina and different retinal cell types.

Methods Three techniques of ganglioside extraction and purification based on solvent phase partition and solid phase extraction were compared and applied to retina samples. Gangliosides were then analyzed by high performance thin layer chromatography and colorimetric revelation, and identified by comigration with standards.

Results Rat whole retina mainly contained complex polysialogangliosides. GD3 appeared to be the major one, followed by GD1b, GT1b and GD1a. In contrast, retinal pigment epithelium cells (ARPE) and Müller cells exhibited a simpler ganglioside profile with a great majority of monosialoganglioside GM3. Small amounts of GM1 and GD3 were also detected, as well as GD1a specifically in Müller cells. Moreover, Müller cells contained larger amounts of gangliosides than ARPE cells.

Conclusion We showed here the specific ganglioside profile of the rat retina and two specialized retinal cell types: ARPE and Müller cells. It will be interesting to identify specific modifications of ganglioside profile associated with pathological conditions in these cells, which are affected during the development of age‐related macular degeneration and glaucoma, respectively.
Pasireotide (SOM230) protects the retina from ischemia induced retinopathies
Authors: KOKONA D , MASTRODIMOU N , PEDIADITAKIS S , CHARALAMPOPOULOS I , SCHMID HA
Published: December 2011

Purpose The aim of the present study was to investigate the neuroprotective properties of SOM230, a new metabolically stable analogue of somatostatin, with a 12h plasma half‐life and high affinity for the sst1,2,3,5 receptor subtypes.

Methods Female Sprague‐Dawley rats (250‐300g) were employed in an ex vivo model of retinal chemical ischemia and an in vivo model of retinal AMPA excitotoxicity. Immunohistochemistry, TUNEL staining, FACS and western blot analysis were employed to examine retinal cell loss and neuroprotection.

Results Chemical ischemia led to the loss of ChAT, bNOS, and PKC immunoreactivity which was reversed by SOM230 in a concentration dependent manner (10‐4‐10‐7 M). Partial protection was observed even at the low concentration of 10‐7M. CYN‐154806 (10‐5M; sst2 antagonist) reversed SOM230 (10‐5M) neuroprotective actions. Similarly, SOM230 (10‐5, 10‐6, 10‐7 M) was neuroprotective (dose‐dependent) in vivo, as was shown by bNOS immunoreactivity studies. An approximate 80% neuroprotection was observed with the dose of 10‐7M. These data were substantiated by TUNEL staining and FACS analysis. The anti‐apoptotic Bcl2 protein was found to be involved in the neuroprotection.

Conclusion SOM230 appears very efficacious in its anti‐apoptotic neuroprotective properties, in both models of retinal ischemia, affording neuroprotection at the concentration or dose of 100nM. These data suggest that sst2/5 analogs with similar pharmacokinetic properties may play an important role alone or in a multi drug treatment in ensuring the most efficacious retinal therapy. [This study was funded by the Graduate Program of Neuroscience to K.T, and the C. Spyraki award to D.K.]
A novel device for the measurement of intraocular pressure, ocular rigidity and pulsatile blood flow.
Authors: KARYOTAKIS NG , GINIS H , TSILIMBARIS MK , SIGGELAKI EM , PALLIKARIS IG
Published: December 2011

Purpose Several instruments and methods are applied for the non invasive measurement of intraocular pressure, ocular rigidity and pulsatily blood flow. Most of this instruments and methods are based on the deformation force‐area principle. The purpose of this study was to present a novel device for the measurement of intraocular pressure, ocular rigidity and pulsatily blood flow.

Methods The device consists of an opto‐mechanical head comprising a deformation sensor and a force sensor, a camera and a microstepping motor. The deformation sensor is an optoelectronic device consisting of two beamsplitters a plano‐convex lens, an illuminating fiber and a receiving fiber. Eighty three eyes were enrolled in a preliminary study, the intraocular pressure was measured with the novel device followed by a Goldman applanation tonometer measurement.

Results The average IOP measured by the device was 17 (std 5.38) mmHg and the average rigidity coefficient was 0.01013 (std 0.039)μl‐1, the IOP measured by the GAT was 13.9 (std 3.23) mmHg. The statistical analysis indicated a significant statistical difference (p=9*10‐8) between the two devices.

Conclusion Significant errors of the measurement are related to the centration of the optical head and the hand driven indentation. To overcome these limitations the device was upgraded with the addition of a coaxial camera for centration control and a microstepping motor for the applanation movement. An investigation of the accuracy and repeatability of the system with these new additions is underway.
Effect of lacritin, a novel glycoprotein, on ocular surface and tear film integrity
Authors: SAMUDRE S , LATTANZIO F , WILLIAMS P , MCKOWN R , LAURIE G
Published: December 2011

Purpose Dry eye is extremely common and debilitating. Treatment options are palliative at best and do not address the underlying pathology. Lacritin, a newly discovered glycoprotein, is secreted naturally in human tears by the lacrimal gland. Human recombinant lacritin stimulated tear secretion in normal rabbits and is well tolerated, leading us to hypothesize that topical application of lacritin will not adversely affect ocular surface and tear film integrity.

Methods We compared full length lacritin construct with cyclosporin (Restasis®), in terms of tear break up time (TBUT) and goblet cell density using impression cytology. Lacritin (10, 50 μg/ml), or cyclosporin (0.05%), were administered bilaterally to New Zealand white rabbits three times daily for 14d (n=4/group).

Results TBUT after lacritin (10 or 50 μg/ml) treatment was 12±2sec, which was similar to vehicle alone, but significantly decreased after cyclosporine treatment for 14d (6±3sec, p<0.001). Preliminary results indicate that goblet cell density decreased by 7±8% after cyclosporine but was not decreased after lacritin. No local irritant effects were noted by slit lamp examination after lacritin treatment, but redness and mild congestion were present in the cyclosporin group.

Conclusion Thus, treatment with lacritin was better tolerated than cyclosporin. This data suggests that lacritin does not adversely ocular surface and tear film integrity when compared to cyclosporine. Evaluation with inflammatory markers, such as CD‐11c, is currently ongoing. Glycoproteins, such as, lacritin, represent a new, unique therapeutic approach that may more closely address the pathology of dry eye.

Commercial interest
Glare visual performance in young subjects under night driving conditions
Authors: PEREZ CARRASCO MJ , PUELL MC , PALOMO‐ALVAREZ C , BARRIO AR , GONZALEZ‐RUGARCIA A , LOPEZ‐SERRANO T
Published: December 2011

Purpose Purpose: Under night driving conditions visual performance is compromised and become worse with disability glare, age and certain ocular pathologies. The aim of this study was to analyze mesopic visual function of young subjects.

Methods Methods: The sample included 37 right eyes of healthy young adults (22.2 ± 1.8 years). The selected criteria were: Best‐corrected VA of at least 0.04 logMAR, and refraction ≤± 3.75. Under mesopic (0.1 to 0.2 cd/m2) luminance conditions and with the best‐optical correction in the right eye, the logMAR VA was measured using high‐contrast (HC‐96%) and low‐contrast (LC‐10%) logMAR Bailey‐Lovie letter charts, and the mesopic contrast sensitivity (CS) without / with glare was assessed with Mesotest II. The intraocular straylight was measured with the C‐Quant.

Results Results: Under mesopic conditions, the HC and LC logMAR VA was 0.28 ± 0.1 and 0.70 ± 0.1 respectively, showing a significant correlation between them (Pearson’s correlation = 0.75; p< 0.00); The mesopic log CS without glare was 0.19 ± 0.1 and with glare was 0.11 ± 0.1. Disability glare induced a 42% decrease in mesopic log CS (p < 0.00). LC logMAR VA was significant correlated with mesopic log CS without and with glare (Pearson’s correlation = 0.4, p< 0.02, and 0.42, p< 0.02 respectively). The intraocular straylight Log (s) was 0.87 ± 0.1, but did not show any significant association with logMAR VA nor the log CS without and with glare under mesopic luminance conditions.

Conclusion Conclusions: The results indicated that mesopic assessment of the low contrast logMAR VA and log CS without and with glare might potentially predict the glare visual performance under night driving conditions.
Halo size in healthy subjects
Authors: PUELL MC , RODRIGUEZ‐ORTEGA J , PEREZ‐CARRASCO MJ , PALOMO‐ALVAREZ C , BARRIO AR
Published: December 2011

Purpose The measurement of the halo size has been proposed as an objective method to characterize the quality of vision in refractive surgery patients who complain of night vision problems. Our purpose was to know the size of halo in the visual field of healthy subjects using a commercial campimeter and to analyze the effect of age.

Methods Measurements were obtained in the better eye of 90 healthy subjects (mean age 46.5±19.4). Halo was measured using the MON CV‐3 campimeter that is equipped with high luminance light sources (200,000 cd/m2) which generated the halo source. The test was performed using optotypes of low luminance (1 cd/m2 and 5 cd/m2) presented over a dark background at a distance of 2.5 m. Optotypes were viewed under a visual angle of 15 arc minutes. Three measurements were taken starting from the side opposite to the light source. The outer limit of the halo was recorded and the visual angle subtended by the radius of the halo was then calculated in arc minutes. Furthermore, the pupil size was evaluated under mesopic conditions with the Colvard pupillometer.

Results Mean halo size was 111.7 ± 41.4 arc min using optotypes of 1 cd/m2 and 44.5 ± 30.3 arc min with 5 cd/m2. A significant positive correlation was found between halo and age at both luminance levels: 1 cd/m2 (r = 0.56; p = 0.00001) and 5cd/m2 (r = 0.57; p = 0.00001). With age there was a significant increase of halo size of 10 arc min per decade at both luminance levels. The halo size did not depend on the pupil diameter.

Conclusion In healthy eyes, halo size in the visual field increased significantly across the lifespan. Measuring the size of the halo using a campimeter is a useful tool for assessing visual impairment caused by glare.
A new method for assessing central and peripheral visual acuity
Authors: CHUNG H , LEE YW , SEO JM
Published: December 2011

Purpose This research aims to assess central and peripheral visual acuity in human.

Methods We assume that visual acuity will decrease in peripheral vision because the density of human photoreceptor cone cells diminishes exponentially. We designed a program to measure visual acuity in two different models (minimum discernible, minimum separable) According to the distance between subject’s eye and screen, this program has 3 cases (basic, release, accumulate model), which are classified by position of nodal points. In addition, there is a selection of four different line patterns to define visual field. After all these options are selected, the program displays various‐sized circles (discernible model) and Landolt rings (separable model) on the locations of screen corresponding to the visual angle.

Results Distribution of visual acuity according to the visual angle could be acquired by proposed method. Central visual acuity was nearly 20/20 and the peripheral visual acuity was diminished according to the increment of visual angle in normal volunteers.

Conclusion Distribution of the visual acuity according to the visual angle corresponded to the density of the photoreceptor cone cells, not to the density of the rod cells. Developed program and system might be useful for other researches concerning visual acuity.
COMPLEXITIES OF THE “TRANSACTIONAL SEX” MODEL: NON‐PROVIDING MEN, SELF‐PROVIDING WOMEN, AND HIV RISK IN RURAL MALAWI
Authors: Verheijen Janneke
Published: December 2011

The “transactional sex” model, which is increasingly used to explain the continued spread of HIV throughout sub‐Saharan Africa and consequently inform policy, overlooks certain important cultural and socioeconomic aspects of women's sexual choices. This chapter is based on a one‐year anthropological field study in rural Malawi on the impacts of improved economic security on women's sexual choices. While confirming the widespread assumption that the direct need for material support plays a role in poor women's decisions to readily accept sexual proposals from men, findings reveal that the depiction of women as powerless victims forced to transactional sex by acute destitution does not necessarily hold. It is argued that the model should be expanded to acknowledge women's agency, and include less direct gains such as community membership and social security.
Resistive switching properties of plasma enhanced-ALD La2O3 for novel nonvolatile memory application
Authors: Chen Lin , Yang Wen , Li Ye , Sun Qing-Qing , Zhou Peng , Lu Hong-Liang , Ding Shi-Jin , Zhang David Wei
Published: December 2011

Plasma enhanced (PE) atomic layer deposition (ALD) of lanthanum oxide films on silicon and platinum substrates were examined using lanthanum-2,2,6,6-tetramethyl-3,5-heptanedione, and O2 plasma as precursors. The effect of pulse time and deposition temperature on the growth rate was investigated. Resistive switching behaviors of La2O3 prepared by PE-ALD were investigated as a promising candidate for next generation nonvolatile memory technology. The crystalline structure of the obtained film was found to be polycrystalline by transmission electron microscope and the chemical composition of the film was estimated to be stoichiometric La2O3 by x ray photoelectron spectroscopy. The low resistance ON state and high resistance OFF state can be reversibly altered under a low voltage about 1.5 and −0.6 V. More than 1000 reproducible switching cycles by dc voltage sweep were observed with a resistance ratio above 100, which was large enough to read out without obvious degradation. Moreover, the estimated working characteristics such as set and reset voltages distribution were sufficiently stable to fulfill requirement for memory application. Considering the excellent memory switching behavior, resistance switch device composed of a promising ALD high-k La2O3 dielectric film is a possible candidate to be integrated into future memory processes.
Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell
Authors: Semonin Octavi E. , Luther Joseph M. , Choi Sukgeun , Chen Hsiang-Yu , Gao Jianbo , Nozik Arthur J. , Beard Matthew C.
Published: December 2011

An experimental solar cell productively uses an extra fraction of high-energy light typically lost as heat.
Flattering to Deceive
The Folly of Fools
The Logic of Deceit and Self-Deception in Human Life

by Robert Trivers

Basic Books (Perseus), New York, 2011. 413 pp. $28, C$32.50. ISBN 9780465027552.
Authors: Bolhuis Johan J.
Published: December 2011

Trivers argues that selection has favored the ability to hide reality from ourselves because doing so makes us better at deceiving others.
Arranging Reactive Meetings of Cold Radicals
Authors: Sims Ian R.
Published: December 2011

The challenging determination of the rate of reaction of nitrogen atoms with hydroxyl radicals at low temperatures may affect models of interstellar dinitrogen formation.
Closing the Cycle
Authors: Meeks John C.
Published: December 2011

Identification of two proteins closes a key metabolic cycle previously thought to be incomplete in cyanobacteria.
Autophagy in Tumor Immunity
Authors: Amaravadi Ravi K.
Published: December 2011

Chemotherapeutic drugs can induce cancer cells to release a chemoattractant that draws immune cells into the tumor microenvironment.
Science and Law: Rattled by Quakes
Authors: Cohen Joel E.
Published: December 2011

When good risk assessments improve financial, environmental, or health decisions, society often does not recognize the combined efforts of stakeholders who brought good management to bear. But when disaster strikes, the interface between science and public policy can come into question. A recent example is the 6.3-magnitude earthquake that struck the Italian city of L'Aquila in early April 2009, destroying 20,000 buildings, displacing 65,000 people, injuring more than 1500, and killing more than 300. This region suffered earlier severe earthquakes and experienced swarms of tremors beginning in 2008. A National Commission for Prediction and Prevention of Major Risks met briefly in late March 2009 to evaluate and communicate the risks in L'Aquila. In September 2011, the six scientists and one bureaucrat comprising this commission were put on trial in Italy. The charges are not simple, and the trial is expected to last months or years. The indictment raised outcries from many geoscientists and some scientific organizations, who pointed out that no scientific method reliably predicts the occurrence of an earthquake. The controversy also raised questions about how well scientific information is conveyed to the public and how well policymakers and lawyers understand the nature of science.
Committee Recommends NIH Continue Chimpanzee Research, With New Limits
Authors: Cohen Jon
Published: December 2011

A committee commissioned by the U.S. National Institutes of Health has recommended that NIH should continue funding biomedical and behavioral research with chimpanzees, but with new stipulations.
Piercing the Veil of Ayurveda
Authors: Bagla Pallava
Published: December 2011

Enthusiasts hope that clinical trials of Ayurvedic medicines will buff the ancient art's tarnished reputation.
Real-Time PCR Using Mycobacteriophage DNA for Rapid Phenotypic Drug Susceptibility Results for Mycobacterium tuberculosis
Authors: Pholwat Suporn , Ehdaie Beeta , Foongladda Suporn , Kelly Kimberly , Houpt Eric
Published: December 2011

Managing drug-resistant
Mycobacterium tuberculosis
requires drug susceptibility testing, yet conventional drug susceptibility testing is slow, and molecular testing does not yield results for all antituberculous drugs. We addressed these challenges by utilizing real-time PCR of mycobacteriophage D29 DNA to evaluate the drug resistance of clinical
M. tuberculosis
isolates. Mycobacteriophages infect and replicate in viable bacterial cells faster than bacterial cells replicate and have been used for detection and drug resistance testing for
M. tuberculosis
either by using reporter cells or phages with engineered reporter constructs. Our primary protocol involved culturing
M. tuberculosis
isolates for 48 h with and without drugs at critical concentrations, followed by incubation with 10
3
PFU/ml of D29 mycobacteriophage for 24 h and then real-time PCR. Many drugs could be incubated instantly with
M. tuberculosis
and phage for 24 h alone. The change in phage DNA real-time PCR cycle threshold (

C
T

) between control
M. tuberculosis
and
M. tuberculosis
treated with drugs was calculated and correlated with conventional agar proportion drug susceptibility results. Specifically, 9 susceptible clinical isolates, 22 multidrug-resistant (MDR), and 1 extensively drug-resistant (XDR)
M. tuberculosis
strains were used and

C
T

control-

C
T

drug cutoffs of between +0.3 and −6.0 yielded 422/429 (98%) accurate results for isoniazid, rifampin, streptomycin, ethambutol, amikacin, kanamycin, capreomycin, ofloxacin, moxifloxacin, ethionamide, para-aminosalicylic acid, cycloserine, and linezolid. Moreover, the Δ

C
T

values correlated with isolate MIC for most agents. This D29 quantitative PCR assay offers a rapid, accurate, 1- to 3-day phenotypic drug susceptibility test for first- and second-line drugs and may suggest an approximate MIC.
Staph ID/R: a Rapid Method for Determining Staphylococcus Species Identity and Detecting the
mecA
Gene Directly from Positive Blood Culture
Authors: Pasko Chris , Hicke Brian , Dunn John , Jaeckel Heidi , Nieuwlandt Dan , Weed Diane , Woodruff Evelyn , Zheng Xiaotian , Jenison Robert
Published: December 2011

Rapid diagnosis of staphylococcal bacteremia directs appropriate antimicrobial therapy, leading to improved patient outcome. We describe herein a rapid test (<75 min) that can identify the major pathogenic strains of
Staphylococcus
to the species level as well as the presence or absence of the methicillin resistance determinant gene,
mecA
. The test, Staph ID/R, combines a rapid isothermal nucleic acid amplification method, helicase-dependent amplification (HDA), with a chip-based array that produces unambiguous visible results. The analytic sensitivity was 1 CFU per reaction for the
mecA
gene and was 1 to 250 CFU per reaction depending on the staphylococcal species present in the positive blood culture. Staph ID/R has excellent specificity as well, with no cross-reactivity observed. We validated the performance of Staph ID/R by testing 104 frozen clinical positive blood cultures and comparing the results with
rpoB
gene or 16S rRNA gene sequencing for species identity determinations and
mecA
gene PCR to confirm
mecA
gene results. Staph ID/R agreed with
mecA
gene PCR for all samples and agreed with
rpoB
/16S rRNA gene sequencing in all cases except for one sample that contained a mixture of two staphylococcal species, one of which Staph ID/R correctly identified, for an overall agreement of 99.0% (
P
< 0.01). Staph ID/R could potentially be used to positively affect patient management for
Staphylococcus
-mediated bacteremia.
Real-Time Qualitative PCR for 57 Human Adenovirus Types from Multiple Specimen Sources
Authors: Buckwalter Seanne P. , Teo Rose , Espy Mark J. , Sloan Lynne M. , Smith Thomas F. , Pritt Bobbi S.
Published: December 2011

Human adenoviruses (HAdVs) are ubiquitous double-stranded DNA viruses that cause a wide array of diseases in humans including pharyngitis, pneumonia, gastroenteritis, hemorrhagic cystitis, and keratoconjunctivitis. They also cause life-threatening opportunistic infections in immunocompromised individuals and are responsible for outbreaks in certain populations. Diagnosis is traditionally by cell culture or antigen detection methods. However, some HAdVs can take up to 4 weeks to isolate, and diarrheagenic types 40 and 41 will not grow in routine cell culture. Therefore, the goal of this study was to design a rapid, real-time PCR assay to detect all known 57 HAdV types from multiple different specimen sources. Primers and fluorescence resonance energy transfer hybridization probes were designed to target a 185-bp region of the penton base gene of HAdV. The analytical sensitivity was determined to be 10 copies/μl for HAdV types showing exact primer/probe homology in specimen matrix. Using whole-virus strains, the analytical sensitivity for representative HAdV types ranged from 10
−1
to 10
3
50% tissue culture infective dose (TCID
50
)/ml. The assay demonstrated 100% sensitivity and 99% specificity. This real-time PCR assay provides a rapid method for the detection of all 57 known HAdV types from respiratory specimens, blood, stool, urine, and ocular swabs.
A New Real-Time Quantitative PCR for Diagnosis and Monitoring of HIV-1 Group O Infection
Authors: Gueudin Marie , Leoz Marie , Lemée Véronique , De Oliveira Fabienne , Vessière Aurélia , Kfutwah Anfumbom , Plantier Jean-Christophe
Published: December 2011

The correct diagnosis and monitoring of HIV-1 group O (HIV-O) infection are essential for appropriate patient management, for the prevention of mother-to-child transmission, and for the detection of dual HIV-M/HIV-O infections. HIV-O RNA quantification is currently possible with two commercial kits (from Abbott and Roche), which quantify HIV-M and HIV-O strains indifferently; therefore, they cannot be used for the specific identification of HIV-O infection. We designed a new real-time quantitative reverse transcription PCR (RT-qPCR assay) (INT-O), which we compared with our previous version, LTR-O, and with the Abbott RealTime HIV-1 kit. Specificity was assessed with 27 HIV-1 group M strains and the prototype strain of group P. Clinical performances were analyzed by using 198 stored plasma samples, representative of HIV-O genetic diversity. Analytical sensitivity, repeatability, and reproducibility were also determined. The detection limit of the INT-O assay was 40 copies/ml, and its specificity was 100%. The repeatability and reproducibility were excellent. Analysis of clinical samples showed a good correlation between the INT-O and LTR-O assays (
r
= 0.8240), with an improvement of analytical sensitivity. A good correlation was also obtained between the INT-O and Abbott assays (
r
= 0.8599) but with significantly higher values (0.19 logs) for the INT-O method, due to marked underquantifications for some patients. These results showed that HIV-O genetic diversity still has an impact on RNA quantification. The new assay, INT-O, allows both the specific diagnosis of HIV-O infection and the quantification of diverse HIV-O strains. Its detection limit is equivalent to that of commercial kits. This assay is cheap and suitable for use in areas in which strains of HIV-1 groups M and O cocirculate.
Occurrence of Putative Virulence Genes in Arcobacter Species Isolated from Humans and Animals
Authors: Douidah Laid , de Zutter Lieven , Baré Julie , De Vos Paul , Vandamme Peter , Vandenberg Olivier , Van den Abeele Anne-Marie , Houf Kurt
Published: December 2011

Interest in arcobacters in veterinary and human public health has increased since the first report of the isolation of arcobacters from food of animal origin. Since then, studies worldwide have reported the occurrence of arcobacters on food and in food production animals and have highlighted possible transmission, especially of
Arcobacter butzleri
, to the human population. In humans, arcobacters are associated with enteritis and septicemia. To assess their clinical relevance for humans and animals, evaluation of potential virulence factors is required. However, up to now, little has been known about the mechanisms of pathogenicity. Because of their close phylogenetic affiliation to the food-borne pathogen
Campylobacter
and their similar clinical manifestations, the presence of nine putative
Campylobacter
virulence genes (
cadF
,
ciaB
,
cj1349
,
hecA
,
hecB
,
irgA
,
mviN
,
pldA
, and
tlyA
) previously identified in the recent
Arcobacter butzleri
ATCC 49616 genome sequence was determined in a large set of human and animal
Arcobacter butzleri
,
Arcobacter cryaerophilus
, and
Arcobacter skirrowii
strains after the development of rapid and accurate PCR assays and confirmed by sequencing and dot blot hybridization.
Multidrug-Resistant Streptococcus pneumoniae Serotype 6D Clones in South Korea
Authors: Ko Kwan Soo , Baek Jin Yang , Song Jae-Hoon
Published: December 2011

To investigate the characteristics of mainStreptococcus pneumoniaeclones of serotype 6D (ST282 and ST3171) in South Korea, antimicrobial susceptibility testing was performed, and 11 genes around thecpslocus were sequenced on ST2826D, ST31716D, and ST816Aisolates. The antimicrobial susceptibility patterns were very similar between clones belonging to the same clonal complex, ST816Aand ST2826D; nonsusceptibilities to penicillin and cefuroxime, high MICs of ceftriaxone, and high resistance rates to trimethoprim-sulfamethoxazole. However, ST31716Disolates showed resistance to only macrolides and clindamycin. The sequences of 11 genes around thecpslocus indicated the same genetic backgrounds between the ST816Aand ST2826Disolates. On the other hand, ST31716Disolates showed nucleotide and amino acid differences from ST816Aand ST2826Disolates in most genes, indicating a different genetic background. The mosaic structure ofdexBgene in ST2826Disolates indicated that recombination might occur in thedexBgene. Our results suggest that the multidrug-resistant ST2826Dpneumococcal clone has emerged by serial genetic recombination, including capsular switch.
Effect of Pneumococcal Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in Fijian Children
Authors: Dunne Eileen M. , Manning Jayne , Russell Fiona M. , Robins-Browne Roy M. , Mulholland E. Kim , Satzke Catherine
Published: December 2011

The 7-valent pneumococcal conjugate vaccine (PCV7) reduces carriage of vaccine type
Streptococcus pneumoniae
but leads to replacement by nonvaccine serotypes and may affect carriage of other respiratory pathogens. We investigated nasopharyngeal carriage of
S. pneumoniae
,
Haemophilus influenzae
,
Moraxella catarrhalis
, and
Staphylococcus aureus
in Fijian infants participating in a pneumococcal vaccine trial using quantitative PCR. Vaccination did not affect pathogen carriage rates or densities, whereas significant differences between the two major ethnic groups were observed.
The Vaccinia Virus O1 Protein Is Required for Sustained Activation of Extracellular Signal-Regulated Kinase 1/2 and Promotes Viral Virulence
Authors: Schweneker Marc , Lukassen Susanne , Späth Michaela , Wolferstätter Michael , Babel Eveline , Brinkmann Kay , Wielert Ursula , Chaplin Paul , Suter Mark , Hausmann Jürgen
Published: December 2011

Sustained activation of the Raf/MEK/extracellular signal-regulated kinase (ERK) pathway in infected cells has been shown to be crucial for full replication efficiency of orthopoxviruses in cell culture. In infected cells, this pathway is mainly activated by the vaccinia virus growth factor (VGF), an epidermal growth factor (EGF)-like protein. We show here that chorioallantois vaccinia virus Ankara (CVA), but not modified vaccinia virus Ankara (MVA), induced sustained activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in infected human 293 cells, although both viruses direct secretion of functional VGF. A CVA mutant lacking the O1L gene (CVA-ΔO1L) demonstrated that the O1 protein was required for sustained upregulation of the ERK1/2 pathway in 293 cells as well as in other mammalian cell lines. The highly conserved orthopoxvirus O1L gene encodes a predicted 78-kDa protein with a hitherto-unknown function. CVA-ΔO1L showed reduced plaque size and an attenuated cytopathic effect (CPE) in infected cell cultures and reduced virulence and spread from lungs to ovaries in intranasally infected BALB/c mice. Reinsertion of an intact O1L gene into MVA, which in its original form harbors a fragmented O1L open reading frame (ORF), restored ERK1/2 activation in 293 cells but did not increase replication and spread of MVA in human or other mammalian cell lines. Thus, the O1 protein was crucial for sustained ERK1/2 activation in CVA- and MVA-infected human cells, complementing the autocrine function of VGF, and enhanced virulence
in vivo
.
Natural Killer Cells Are Involved in Acute Lung Immune Injury Caused by Respiratory Syncytial Virus Infection
Authors: Li Fengqi , Zhu Hanqing , Sun Rui , Wei Haiming , Tian Zhigang
Published: December 2011

It is known that respiratory syncytial virus (RSV) is the main cause of bronchiolitis and pneumonia in young children. RSV infection often leads to severe acute lung immunopathology, but the underlying immune mechanisms are not yet fully elucidated. Here, we found that RSV infection induced severe acute lung immune injury and promoted the accumulation and activation of lung natural killer (NK) cells at the early stage of infection in BALB/c mice. Activated lung NK cells highly expressed activating receptors NKG2D and CD27 and became functional NK cells by producing a large amount of gamma interferon (IFN-γ), which was responsible for acute lung immune injury. NK cell depletion significantly attenuated lung immune injury and reduced infiltration of total inflammatory cells and production of IFN-γ in bronchoalveolar lavage fluid (BALF). These data show that NK cells are involved in exacerbating the lung immune injury at the early stage of RSV infection via IFN-γ secretion.
CRM1-Dependent Transport Supports Cytoplasmic Accumulation of Adenoviral Early Transcripts
Authors: Schmid Melanie , Gonzalez Ramon A. , Dobner Thomas
Published: December 2011

The life cycle of adenoviruses is divided by convention into early and late phases, separated by the onset of viral genome replication. Early events include virus adsorption, transport of the genome into the nucleus, and the expression of early genes. After the onset of viral DNA replication, transcription of the major late transcription unit (MLTU) and thereby synthesis of late proteins is induced. These steps are controlled by an orchestra of regulatory processes and require import of the genome and numerous viral proteins into the nucleus, as well as active transport of viral transcripts and proteins from the nucleus to the cytoplasm. The latter is achieved by exploiting the shuttling functions of cellular transport receptors, which normally stimulate the nuclear export of cellular mRNA and protein cargos. A set of adenoviral early and late proteins contains a leucine-rich nuclear export signal of the HIV-1 Rev type, known to be recognized by the cellular export receptor CRM1. However, a role for CRM1-dependent export in supporting adenoviral replication has not been established. To address this issue in detail, we investigated the impact of two different CRM1 inhibitors on several steps of the adenoviral life cycle. Inhibition of CRM1 led to a reduction in viral early and late gene expression, viral genome replication, and progeny virus production. For the first time, our findings indicate that CRM1-dependent shuttling is required for the efficient export of adenoviral early mRNA.
Role of O-Glycosylation and Expression of CD43 and CD45 on the Surfaces of Effector T Cells in Human T Cell Leukemia Virus Type 1 Cell-to-Cell Infection
Authors: Mazurov Dmitriy , Ilinskaya Anna , Heidecker Gisela , Filatov Alexander
Published: December 2011

We used replication-dependent retroviral vectors to identify cell surface antigens involved in the cell-to-cell transmission of human T cell leukemia virus type 1 (HTLV-1). We generated monoclonal antibodies (MAbs) against Jurkat T cells and selected several IgM MAbs that strongly inhibited HTLV-1 but not human immune deficiency virus type 1 (HIV-1) cell-to-cell infection. These MAbs recognized the so-called Tn antigen (GalNAcα1-O-Ser/Thr) that arises on Jurkat cells from a mutation in the T-synthase-specific chaperone Cosmc and the consequent loss ofO-glycan elongation. Anti-Tn MAbs precipitated two majorO-glycan carrier proteins, CD43 and CD45, and caused a strong aggregation of Jurkat cells. The restoration of O-glycosylation in Jurkat cells by stably transducing the wild-typeCosmcgene resulted in a 3- to 4-fold increase in the level of surface expression of CD43 and enhanced HTLV-1 transmission 10-fold in comparison to that of parental cells. The short hairpin RNA (shRNA) knockdown of CD43 or CD45 expression in Jurkat-Cosmc, HBP-ALL, and CEM T cells decreased HTLV-1 infection severalfold. The knockdown of CD45 in Jurkat cells severely reduced both HTLV-1 and HIV-1 infections, but Cosmc coexpression partially rescued infection. HTLV-1 proteins, which assembled in small patches on Jurkat cells, formed large clusters on the surface of Jurkat-Cosmc cells. These data indicate that large aggregates of HTLV-1 assemblies are more infectious than multiple clustered virions. We suggest that heavily O-glycosylated CD43 and CD45 molecules render cells less adhesive, prevent inappropriate cell-cell contacts, and favor the assembly of HTLV-1 particles into large, highly infectious structures on the surface of T cells.
Core groups, antimicrobial resistance and rebound in gonorrhoea in North America
Authors: Chan Christina H , McCabe Caitlin J , Fisman David N
Published: December 2011

Background

Genital tract infections caused byNeisseria gonorrhoeaeare a major cause of sexually transmitted disease worldwide. Surveillance data suggest that incidence has increased in recent years after initially falling in the face of intensified control efforts.

Objectives

The authors sought to evaluate the potential contribution of antimicrobial resistance to such rebound and to identify optimal treatment strategies in the face of resistance using a mathematical model of gonorrhoea.

Methods

The authors built risk-structured ‘susceptible–infectious–susceptible’ models with and without the possibility of antibiotic resistance and used these models as a platform for the evaluation of competing plausible treatment strategies, including changing antimicrobial choice when resistance prevalence surpassed fixed thresholds, random assignment of treatment and use of combination antimicrobial therapy.

Results

Absent antimicrobial resistance, strategies that focus on treatment of highest risk individuals (the so-called core group) result in collapse of disease transmission. When antimicrobial resistance exists, a focus on the core group causes rebound in incidence, with maximal dissemination of antibiotic resistance. Random assignment of antimicrobial treatment class outperformed the use of fixed resistance thresholds with respect to sustained reduction in gonorrhoea prevalence.

Conclusions

Gonorrhoea control is achievable only when core groups are treated, but treatment of core groups maximises dissemination of antimicrobial-resistant strains. This paradox poses a great dilemma to the control and prevention of gonorrhoea and underlines the need for gonococcal vaccines.
SUPERLUMINAL NEUTRINOS FROM GAUGE FIELD
Authors: ODA ICHIRO , TAIRA HAJIME
Published: December 2011

We consider a possibility that the recent OPERA results on neutrinos' superluminality could be caused by a local effect of a new gauge field sourced by the earth. If neutrinos couple to this gauge field via a gauge-invariant but non-renormalizable interaction, the coupling effectively changes a background metric, thereby leading to superluminality of neutrinos. This possibility might naturally explain why neutrinos from CERN CNGS beam to Gran Sasso Laboratory become superluminal while those from SN1987A to Earth become subluminal.
Pre-steady-state and reverse transport currents in the GABA transporter GAT1
Authors: Cherubino Francesca , Bertram Simone , Bossi Elena , Peres Antonio
Published: December 2011

The role of internal substrates in the biophysical properties of the GABA transporter GAT1 has been investigated electrophysiologically in Xenopus oocytes heterologously expressing the cotransporter. Increments in Cl− and/or Na+ concentrations caused by intracellular injections did not produce significant effects on the pre-steady-state currents, while a positive shift of the charge-voltage ( Q–V) and decay time constant (τ)-voltage (τ- V) curves, together with a slowing of τ at positive potentials, was observed following treatments producing cytosolic Cl− depletion. Activation of the reverse transport mode by injections of GABA caused a reduction in the displaced charge. In the absence of external Cl−, a stronger reduction in the displaced charge, together with a significant increase in reverse transport current, was observed. Therefore, complementarity between pre-steady-state and transport currents, observed in the forward mode, is preserved in the reverse mode. All these findings can be qualitatively reproduced by a kinetic scheme in which, in the forward mode, the Cl− ion is released first, after the inward charge movement, while the two Na+ ions can be released only after binding of external GABA. In the reverse mode, internal GABA must bind first to the empty transporter, followed by internal Na+ and Cl−.
Distinct roles of specific fatty acids in cellular processes: implications for interpreting and reporting experiments
Authors: Watt Matthew J. , Hoy Andrew J. , Muoio Deborah M. , Coleman Rosalind A.
Published: December 2011

Plasma contains a variety of long-chain fatty acids (FAs), such that about 35% are saturated and 65% are unsaturated. There are countless examples that show how different FAs impart specific and unique effects, or even opposing actions, on cellular function. Despite these differing effects, palmitate (C16:0) is regularly used to represent “FAs” in cell based experiments. Although palmitate can be useful to induce and study stress effects in cultured cells, these effects in isolation are not physiologically relevant to dietary manipulations, obesity, or the consequences of physiological concentrations of FAs. Hence, authors should avoid conclusions that generalize about “FAs” or “saturated FAs” or “high-fat diet” effects if only a single FA was used in the reported experiments.
Functional differentiation of myoglobin isoforms in hypoxia-tolerant carp indicates tissue-specific protective roles
Authors: Helbo Signe , Dewilde Sylvia , Williams Daryl R. , Berghmans Herald , Berenbrink Michael , Cossins Andrew R. , Fago Angela
Published: December 2011

Because of a recent whole genome duplication, the hypoxia-tolerant common carp and goldfish are the only vertebrates known to possess two myoglobin (Mb) paralogs. One of these, Mb1, occurs in oxidative muscle but also in several other tissues, including capillary endothelial cells, whereas the other, Mb2, is a unique isoform specific to brain neurons. To help understand the functional roles of these diverged isoforms in the tolerance to severe hypoxia in the carp, we have compared their O2 equilibria, carbon monoxide (CO) and O2 binding kinetics, thiol S-nitrosation, nitrite reductase activities, and peroxidase activities. Mb1 has O2 affinity and nitrite reductase activity comparable to most vertebrate muscle Mbs, consistent with established roles for Mbs in O2 storage/delivery and in maintaining nitric oxide (NO) homeostasis during hypoxia. Both Mb1 and Mb2 can be S-nitrosated to similar extent, but without oxygenation-linked allosteric control. When compared with Mb1, Mb2 displays faster O2 and CO kinetics, a lower O2 affinity, and is slower at converting nitrite into NO. Mb2 is therefore unlikely to be primarily involved in either O2 supply to mitochondria or the generation of NO from nitrite during hypoxia. However, Mb2 proved to be significantly faster at eliminating H2O2, a major in vivo reactive oxygen species (ROS), suggesting that this diverged Mb isoform may have a specific protective role against H2O2 in the carp brain. This property might be of particular significance during reoxygenation following extended periods of hypoxia, when production of H2O2 and other ROS is highest.
Review:Novel roles of nuclear angiotensin receptors and signaling mechanisms
Authors: Gwathmey TanYa M. , Alzayadneh Ebaa M. , Pendergrass Karl D. , Chappell Mark C.
Published: December 2011

The renin-angiotensin system (RAS) constitutes an important hormonal system in the physiological regulation of blood pressure. The dysregulation of the RAS is considered a major influence in the development and progression of cardiovascular disease and other pathologies. Indeed, experimental and clinical evidence indicates that blockade of this system with angiotensin-converting enzyme (ACE) inhibitors or angiotensin type 1 receptor (AT1R) antagonists is an effective therapy to attenuate hypertension and diabetic renal injury, and to improve heart failure. Originally defined as a circulating system, multiple tissues express a complete RAS, and compelling evidence now favors an intracellular system involved in cell signaling and function. Within the kidney, intracellular expression of the three predominant ANG receptor subtypes is evident in the nuclear compartment. The ANG type 1 receptor (AT1R) is coupled to the generation of reactive oxygen species (ROS) through the activation of phosphoinositol-3 kinase (PI3K) and PKC. In contrast, both ANG type 2 (AT2R) and ANG-(1–7) (AT7R) receptors stimulate nitric oxide (NO) formation, which may involve nuclear endothelial NO synthase (eNOS). Moreover, blockade of either ACE2—the enzyme that converts ANG II to ANG-(1–7)—or the AT7receptor exacerbates the ANG II-ROS response on renal nuclei. Finally, in a model of fetal programmed hypertension, the nuclear ROS response to ANG II is enhanced, while both AT2and AT7stimulation of NO is attenuated, suggesting that an imbalance in the intracellular RAS may contribute to the development of programming events. We conclude that a functional intracellular or nuclear RAS may have important implications in the therapeutic approaches to cardiovascular disease.
Differential cortical activation during saccadic adaptation
Authors: Blurton Steven P. , Raabe Markus , Greenlee Mark W.
Published: December 2011

The human saccadic system can dynamically adjust its gain if errors occur after saccade execution. Although this ability has long been studied, the underlying neural mechanisms and its functional purpose remain as of yet unclear. Using functional magnetic resonance imaging coupled with gaze-contingent visual stimulation, we compared brain activation before and after subjects adapted to a gaze-contingent shift in the target location (inward step). This comparison suggests the existence of a predictive signal related to the gain adjustment of upcoming saccades to decrease saccadic gain. Contrary to previous studies, we were able to identify activation differences in the supplementary eye fields that vary with the amount of saccadic gain decrease. In addition to signal amplitude differences in saccade-related eye fields, we also found active cortical regions in the temporal lobe and the posterior insula, which have been functionally related to vestibular processing and to the representation of head position and head motion. The results might point to new directions for research on saccadic adaptation pointing to the functional role of this mechanism.
Spectral Approximation of an Oldroyd Liquid Draining down a Porous Vertical Surface
Authors: Akyildiz F. Talay , Koksal Mehmet Emir , Kaplan Nurhan
Published: December 2011

Consideration is given to the free drainage of an Oldroyd four‐constant liquid from a vertical porous surface. The governing systems of quasilinear partial differential equations are solved by the Fourier‐Galerkin spectral method. It is shown that Fourier‐Galerkin approximations are convergent with spectral accuracy. An efficient and accurate algorithm based on the Fourier‐Galerkin approximations for the governing system of quasilinear partial differential equations is developed and implemented. Numerical results indicating the high accuracy and effectiveness of this algorithm are presented. The effect of the material parameters, elasticity, and porous medium constant on the centerline velocity and drainage rate is discussed.
L∞‐Solutions for Some Nonlinear Degenerate Elliptic Equations
Authors: Cavalheiro Albo Carlos
Published: December 2011

We are interested in the existence of solutions for Dirichlet problem associated to the degenerate quasilinear elliptic equations f(x),   on  Ω in the setting of the weighted Sobolev spaces .