bluuebunny/crossref_metadata_2025 huggingface dataset:
Can Single Use Negative Pressure Wound Therapy be an alternative method to manage keloid scarring? A preliminary report of a clinical and ultrasound/colour‐power‐doppler study
Authors: Fraccalvieri Marco , Sarno Antonino , Gasperini Stefano , Zingarelli Enrico , Fava Raffaella , Salomone Marco , Bruschi Stefano
Published: June 2012

Keloid scarring represents a pathological healing where primary healing phenomenon is deviated from normal. Pico is a single use negative pressure wound therapy system originally introduced to manage open or just closed wounds. Pico dressing is made of silicone, and distributes an 80 mmHg negative pressure across wound bed. Combination of silicon layer and continuous compression could be a valid method to manage keloid scarring. Since November 2011, three patients were enrolled and evaluated before negative pressure treatment, at end of treatment (1 month) and 2 months later, through Vancouver Scar Scale (VSS), Visual Analog Scale (VAS) and a scoring system for itching. Ultrasound (US) and colour‐power‐doppler (CPD) examination was performed to evaluate thickness and vascularisation of the scar. One patient was discharged from study after 1 week. In last two patients, VSS, VAS and itching significantly improved after 1 month therapy and the results were stable after 2 months without any therapy. At end of therapy, the ‘appearance of palisade vessels' disappeared in both cases at CPD exam; US showed a thickness reduction (average 43·8%). We propose a well‐tolerated, non invasive treatment to manage keloid scarring. Prospective studies are necessary to investigate whether these preliminary observations are confirmed.
Optimal use of negative pressure wound therapy for skin grafts
Authors: Gupta Subhas
Published: June 2012

Skin grafting is a technique used for transplanting human skin (i.e. epidermal and some dermal layers) from a harvest site to a recipient site. However, advancements in bioengineered matrices have also introduced alternatives to skin grafts. The method used to secure the graft, whether skin or biomatrix, is critical in reducing graft failure. During the past several years, negative pressure wound therapy using reticulated open‐cell foam (NPWT/ROCF; V.A.C.® Therapy, KCI USA, Inc., San Antonio, TX) has become a well‐established method for bolstering grafts to recipient beds and is being used more frequently over biomatrices to help improve graft outcomes. This review will combine expert opinion with scientific evidence for the use of NPWT/ROCF over grafts.
The effectiveness of a four‐layer compression bandage system in comparison with Class 3 compression hosiery on healing and quality of life in patients with venous leg ulcers: a randomised controlled trial
Authors: Finlayson Kathleen J , Courtney Mary D , Gibb Michelle A , O'Brien Jane A , Parker Christina N , Edwards Helen E
Published: June 2012

An increasing number of compression systems available for treatment of venous leg ulcers and limited evidence on the relative effectiveness of these systems are available. The purpose of this study was to conduct a randomised controlled trial to compare the effectiveness of a four‐layer compression bandage system and Class 3 compression hosiery on healing and quality of life (QL) in patients with venous leg ulcers. Data were collected from 103 participants on demographics, health, ulcer status, treatments, pain, depression and QL for 24 weeks. After 24 weeks, 86% of the four‐layer bandage group and 77% of the hosiery group were healed (P = 0·24). Median time to healing for the bandage group was 10 weeks, in comparison with 14 weeks for the hosiery group (P = 0·018). The Cox proportional hazards regression found participants in the four‐layer system were 2·1 times (95% CI 1·2–3·5) more likely to heal than those in hosiery, while longer ulcer duration, larger ulcer area and higher depression scores significantly delayed healing. No differences between groups were found in QL or pain measures. Findings indicate that these systems were equally effective in healing patients by 24 weeks; however, a four‐layer system may produce a more rapid response.
Source Screening Module for Contaminant Transport Analysis Through Vadose and Saturated Zones
Authors: Bedekar Vivek , Neville Christopher , Tonkin Matthew
Published: June 2012

At complex sites there may be many potential sources of contaminants within the vadose zone. Screening‐level analyses are useful to identify which potential source areas should be the focus of detailed investigation and analysis. A source screening module (SSM) has been developed to support preliminary evaluation of the threat posed by vadose zone waste sites on groundwater quality. This tool implements analytical solutions to simulate contaminant transport through the unsaturated and saturated zones to predict time‐varying concentrations at potential groundwater receptors. The SSM integrates several transport processes in a single simulation that is implemented within a user‐friendly, Microsoft Excel™ ‐ based interface.
Modeling Steady Sea Water Intrusion with Single‐Density Groundwater Codes
Authors: Bakker Mark , Schaars Frans
Published: June 2012

Steady interface flow in heterogeneous aquifer systems is simulated with single‐density groundwater codes by using transformed values for the hydraulic conductivity and thickness of the aquifers and aquitards. For example, unconfined interface flow may be simulated with a transformed model by setting the base of the aquifer to sea level and by multiplying the hydraulic conductivity with 41 (for sea water density of 1025 kg/m3). Similar transformations are derived for unconfined interface flow with a finite aquifer base and for confined multi‐aquifer interface flow. The head and flow distribution are identical in the transformed and original model domains. The location of the interface is obtained through application of the Ghyben‐Herzberg formula. The transformed problem may be solved with a single‐density code that is able to simulate unconfined flow where the saturated thickness is a linear function of the head and, depending on the boundary conditions, the code needs to be able to simulate dry cells where the saturated thickness is zero. For multi‐aquifer interface flow, an additional requirement is that the code must be able to handle vertical leakage in situations where flow in an aquifer is unconfined while there is also flow in the aquifer directly above it. Specific examples and limitations are discussed for the application of the approach with MODFLOW. Comparisons between exact interface flow solutions and MODFLOW solutions of the transformed model domain show good agreement. The presented approach is an efficient alternative to running transient sea water intrusion models until steady state is reached.
Rainfall Runoff Relationships for a Cloud Forest Watershed in Central America: Implications for Water Resource Engineering1
Authors: Caballero Luis A. , Rimmer Alon , Easton Zachary M. , Steenhuis Tammo S.
Published: June 2012

Caballero, Luis A., Alon Rimmer, Zachary M. Easton, and Tammo S. Steenhuis, 2012. Rainfall Runoff Relationships for a Cloud Forest Watershed in Central America: Implications for Water Resource Engineering. Journal of the American Water Resources Association (JAWRA) 48(5): 1022‐1031. DOI: 10.1111/j.1752‐1688.2012.00668.x

Abstract:  Understanding the basic relationships between rainfall and runoff is vital for effective management and utilization of scarce water resources. Especially, this is important in Central America with widespread potable water shortage during the dry months of the monsoon. Potential good water sources are cloud forests, but little information concerning its potential is available to water supply engineers. Our objective is to define rainfall‐runoff‐base flow relationships for a cloud forest catchment. Flumes were installed for measuring river flow in four subwatersheds in La Tigra National Park, Honduras. One of the four watersheds was a 636‐ha subwatershed (WS1) with 60% cloud forest coverage. Precipitation averaged 1,130 mm/yr over the entire basin. About half of the total rainfall became runoff for the cloud forest watershed whereas, for the adjacent undisturbed forested watershed, the total discharge was <20% of the amount of precipitation. Infiltration rates were generally greater than rainfall rates. Therefore, most rainfall infiltrated into the soil, especially in the upper, steep, and well‐drained portions of the watershed. Direct runoff was generated from saturated areas near the river and exposed bedrock. This research provides compelling evidence that base flow is the primary contributor to streamflow during both wet and dry seasons in cloud forest catchments. Protecting these flow processes over time is critical for the sustained provision of potable water.
Trust in Citizen Science Research: A Case Study of the Groundwater Education Through Water Evaluation & Testing Program1
Authors: Thornton Teresa , Leahy Jessica
Published: June 2012

Thornton, Teresa and Jessica Leahy, 2012. Trust in Citizen Science Research: A Case Study of the Groundwater Education Through Water Evaluation & Testing Program.Journal of the American Water Resources Association(JAWRA) 48(5): 1032‐1040. DOI: 10.1111/j.1752‐1688.2012.00670.x

Abstract: Data collected by citizen scientists, including K‐12 students, have been validated by the scientific community through quality assurance/quality control tests and publication of results in peer‐reviewed journal articles. However, if citizen science data are to be used by local communities, research is needed to determine which factors contribute to local community member trust in citizen science data, and how to increase the benefits and use of citizen science programs. This article describes the Groundwater Education Through Water Evaluation & Testing (GET WET!) program that employs middle and high school students, state and local government employees, environmental nongovernmental organization leaders, business representatives, college faculty and students, and other volunteers as citizen scientists to create a database of groundwater quality for use as a baseline for local water resources management. Data were gathered through semi‐structured interviews pre‐ and post‐involvement from 40 participants in this citizen science program conducted in five states in the northeastern United States. Results indicate that factors of trust are largely based on interpersonal trust and familiarity. We conclude with recommendations and future research that may improve local community member willingness to trust citizen science data generated by students.
Association of chitotriosidase genotype with the development of non‐alcoholic fatty liver disease
Authors: Di Rosa Michelino , Mangano Katia , De Gregorio Corinne , Nicoletti Ferdinando , Malaguarnera Lucia
Published: June 2012

Aim:  Based on the role of chitotriosidase (CHIT‐1) in the evolution of non‐alcoholic fatty liver disease, we explored whether CHIT‐1 mutant allele plays a role in NAFLD progression.

Methods:  We genotyped 200 patients with NAFLD (110 with non‐alcoholic steatohepatitis [NASH] and 90 with simple steatosis) and 100 control subjects. The χ2‐test was performed for a case–control study. Odds ratios (OR) were adjusted for age, sex and body mass index (BMI) by using multiple logistic regression analysis with genotypes (additive model), age, sex and BMI as the independent variables. Multiple linear regression analysis was performed to test the independent effect of risk allele on clinical parameters while considering the effects of other variables (age, sex and BMI), which were assumed to be independent of the effect of the single nucleotide polymorphism.

Results:  The risk allele frequency of CHIT‐1 wild type (Wt) was 0.71 in the control subjects, 0.77 in simple steatosis and 0.92 in patients with NASH. The OR (95% confidence interval) adjusted for age and BMI was 1.73. Multiple linear regression analysis indicated that the CHIT‐1 Wt was significantly associated with increases in ferritin levels (P = 0.014) and the fibrosis stage (P = 0.011) in the patients with NASH, even after adjustment for age, sex and BMI, corroborating that the presence of the CHIT‐1 Wt allele was an independent predictor of fibrotic NAFLD. In contrast, the steatosis grade was not associated with CHIT‐1 mutant allele.

Conclusion:  These findings suggest that a functional polymorphism in the CHIT‐1 gene protects against NAFLD progression.
Sales Maximization or Profit Maximization? How State Shareholders Discipline their CEOs in China*
Authors: Opper Sonja , Wong Sonia , Yang Yong
Published: June 2012

This study examines the determinants of Chief Executive Officer (CEO) turnover in Chinese state‐owned firms. Based on a sample of 1 555 turnover cases among listed firms in China during the period 1999–2003, we obtain three main results. First, CEO turnover is negatively related to the sales performance but not the profitability of the core business. Second, the negative relationship between CEO turnover and sales is stronger for firms with excessive employment and higher organizational slack. Third, there is a significant post‐turnover increase in sales but a decline in profitability of the core business. Overall, our evidence suggests that state shareholders put a greater emphasis on sales generation than on profitability when they monitor their CEOs.
Oral bioavailability of ketoprofen in suspension and solution formulations in rats: the influence of poloxamer 188
Authors: Fischer Sarah Maud , Parmentier Johannes , Buckley Stephen Timothy , Reimold Isolde , Brandl Martin , Fricker Gert
Published: June 2012

Objectives

The aim of the current study was to investigate the effect of poloxamer 188 (P-188) on the bioavailability of the BCS class 2 drug ketoprofen in vivo.

Methods

Aqueous suspension and solution formulations of ketoprofen with and without P-188 were orally administered to fasted male Wistar rats. The intrinsic dissolution rate and solubility of ketoprofen in simulated intestinal fluid, in both the presence and absence of P-188, was measured.

Key findings

The AUC and Cmax were found to be significantly enhanced when ketoprofen was administered as suspension and P-188 was present in the formulation (Susp P-188) as compared to the surfactant-free formulation (∼4-fold higher AUC, 7-fold higher Cmax). While drug solubility appeared to be almost unaffected by P-188, a significantly faster dissolution was observed. In addition, the influence of P-188 on the drug absorption process was investigated by comparison of solution formulations with and without P-188.

Conclusions

The in-vivo performance of these solutions, a pure buffer solution and a P-188-containing buffer solution showed no significant difference, suggesting that the increase in bioavailability for Susp P-188 was primarily a consequence of the dissolution rate-enhancing effect.
Lifing Requirement Based Turbine Airfoil Mass Estimation Method in Conceptual Aero-Engine Design
Authors: Bretschneider Stefan , Weisser Meinrad , Klingels Hermann , Donus Fabian
Published: June 2012

The presented paper describes a method developed by MTU Aero Engines to estimate the mass of turbine blades during multidisciplinary conceptual design studies based on a prescribed airfoil lifetime (Klingels, 2009, “Vordimensionierung von Turbinenschaufeln unter Berücksichtigung der Missionsanforderungen,” MTU Aero Engines, Technical Paper No. M09TET-0028, and Weisser, M., 2010, Erstellung und Implementierung eines erweiterten regelbasierten Verfahrens zur Schaufelauslegung mit Kühlluftmengenbestimmung in der Triebwerksvorauslegung, Diploma thesis, Institute of Aircraft Propulsion Systems, Universität Stuttgart, Stuttgart). For a given material, the target lifetime can be translated into a maximally allowable material temperature and stress level. While the latter has to be maintained by an appropriate mechanical design of the turbine blades, the material temperature needs to be established by sufficient cooling air. The predominant life-limiting effects are taken into account to determine the allowable temperatures and stresses as an accumulation of the varying operating condition over a flight cycle. The applicable stress levels are then used to calculate the necessary radial area distribution of the airfoil and by this a prediction of its mass is possible. Furthermore, the methodology estimates the required amount of cooling air per airfoil cascade from the computed material temperatures. Example calculations are presented and discussed which illustrate design trends and the benefits which are gained from the proposed method.
A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe
2
(As
1–

x

P

x

)
2
Authors: Hashimoto K. , Cho K. , Shibauchi T. , Kasahara S. , Mizukami Y. , Katsumata R. , Tsuruhara Y. , Terashima T. , Ikeda H. , Tanatar M. A. , Kitano H. , Salovich N. , Giannetta R. W. , Walmsley P. , Carrington A. , Prozorov R. , Matsuda Y.
Published: June 2012

A Spike Inside the Dome

The transition temperature

T
c

of iron-based superconductors has a dome-shaped dependence on chemical doping, and the superconductivity that develops underneath may obscure a potential quantum critical point (QCP) residing at absolute zero. With the aim of detecting signatures of this quantum criticality,

Hashimoto
et al.

(p
1554
; see the Perspective by

Sachdev

) measured the penetration depth of the pnictide series BaFe
2
(As

1−
x

P

x

)
2
as a function of
x.
A sharp peak right around the point where

T
c

has a maximum (
x
= 0.30) was observed, implying that the superfluid density diminishes sharply where one would expect it to be the most robust. This unusual finding is interpreted as a sign of a QCP at
x
= 0.30.
The Fission Yeast FANCM Ortholog Directs Non-Crossover Recombination During Meiosis
Authors: Lorenz Alexander , Osman Fekret , Sun Weili , Nandi Saikat , Steinacher Roland , Whitby Matthew C.
Published: June 2012

No Crossing Over

To ensure the correct division of chromosome during the reduction division of meiosis, homologous chromosomes undergo double-strand breaks that—through crossing over and recombination—link the homologs together (and importantly introduce diversity into the genomes of gametes). But only a minority of these crossovers results in recombination—most are directed into non-crossover pathways.

Lorenz
et al.

(p.
1585
), working in the yeast
Schizosaccharomyces pombe
, and

Crismani
et al.

(p.
1588
), working in the higher plant
Arabidopsis thaliana
, looked for the factors that limit crossovers and promote non-crossover pathways. The homolog of the human
Fanconi anemia complementation group M (FANCM)
helicase protein was found to be a major meiotic anti-recombinase, which could drive meiotic recombination intermediates into the non-crossover pathway.
Electromechanical Properties of Graphene Drumheads
Authors: Klimov Nikolai N. , Jung Suyong , Zhu Shuze , Li Teng , Wright C. Alan , Solares Santiago D. , Newell David B. , Zhitenev Nikolai B. , Stroscio Joseph A.
Published: June 2012

Straining Suspended Graphene

The electronic properties of graphene are best displayed by suspended sheets free from contact with an underlying substrate.

Klimov
et al.

(p.
1557
) probed how deformation of suspended graphene sheets could lead to further tuning of its electronic properties with a scanning tunneling microscope; the graphene sheets could also be deformed via an electric field from an underlying electrode. Spectroscopic studies reveal that the induced strain led to charge-carrier localization into spatially confined quantum dots, an effect consistent with the formation of strain-induced pseudomagnetic fields.
Regulating the Boundaries of Dual-Use Research
Authors: Frankel Mark S.
Published: June 2012

A new U.S. policy for dual-use life science research defines what is permissible by scientists and the government. However, further negotiations will be needed as governments realize the consequences of such boundaries for research and society.
The
lac
Repressor Displays Facilitated Diffusion in Living Cells
Authors: Hammar Petter , Leroy Prune , Mahmutovic Anel , Marklund Erik G. , Berg Otto G. , Elf Johan
Published: June 2012

Slide and Find

Transcription factors rapidly find their specific binding sites on chromosomal DNA. It has been proposed that searching is facilitated by complementing three-dimensional diffusion with one-dimensional diffusion along DNA. Such sliding on DNA has been observed in vitro, but whether and how far transcription factors slide along chromosomes in vivo is unclear.

Hammar
et al.

(p.
1595
) used single-molecule imaging to demonstrate that the
lac
repressor slides into its chromosomal operators in living cells. The average sliding distance was about 45 base pairs, and the repressor frequently slid over its operator before binding.
The Dorsal Aorta Initiates a Molecular Cascade That Instructs Sympatho-Adrenal Specification
Authors: Saito Daisuke , Takase Yuta , Murai Hidetaka , Takahashi Yoshiko
Published: June 2012

Master Regulator

Sympathetic neurons and the adrenal medulla are part of the autonomic nervous system, which is important in the control of a variety of bodily functions and in responses to stress. Interactions between the nervous system and the vascular system have been poorly explored. During development, sympathetic neurons and adrenal medulla cells are derived from the same precursors—neural crest cells—embryonic cohorts that undergo massive migration in the body. Using blood vessel–specific gene manipulation in chicken embryos,

Saito
et al.

(p.
1578
) revealed a role for the dorsal aorta in regulating the early migration of neural crest cells and later in development on the segregation of adrenal medulla and sympathetic neurons. The dorsal aorta expresses multiple soluble morphogenetic and growth factors that regulate complex morphogenesis in a spatiotemporal manner. Furthermore, in mice, the morphogenesis of the adrenal medulla was controlled both by the aorta and the adrenal cortex.
Primed to Remember
Authors: Hewak Dan , Gholipour Behrad
Published: June 2012

With the potential to mimic the human brain, phase-change memories are operating faster, while imaging provides further insight into the switching mechanism.
Wnt Regulates TERT—Putting the Horse Before the Cart
Authors: Greider Carol W.
Published: June 2012

A cell signaling pathway that controls self-renewal also regulates telomerase activity.
Facilitating “A-ha!” Moments
Imagine
How Creativity Works

by Jonah Lehrer

Houghton Mifflin Harcourt, Boston, 2012. 299 pp. $26. ISBN 9780547386072. Canongate, London. £18.99. ISBN 9781847677860.
Authors: Vlasits Anna
Published: June 2012

Blending scientific findings with stories about creative breakthroughs, Lehrer discusses a range of factors that might help spark our imaginations.
Second Bacterium Theory Stirs Haiti's Cholera Controversy
Authors: Kupferschmidt Kai
Published: June 2012

A just-published study is set to reignite the politically sensitive debate about the origins of the cholera epidemic that has killed some 7000 people in Haiti and sickened another half-million since 2010.
For Young Scientists, A Wild Ride
Authors: Enserink Martin
Published: June 2012

The experimental work on the two controversial H5N1 studies known as the Kawaoka and Fouchier papers was done by younger researchers who have remained invisible during the past 8 months.
Response of Simian Immunodeficiency Virus to the Novel Nucleoside Reverse Transcriptase Inhibitor 4′-Ethynyl-2-Fluoro-2′-Deoxyadenosine
In Vitro
and
In Vivo
Authors: Murphey-Corb Michael , Rajakumar Premeela , Michael Heather , Nyaundi Julia , Didier Peter J. , Reeve Aaron B. , Mitsuya Hiroaki , Sarafianos Stefan G. , Parniak Michael A.
Published: June 2012

Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) are essential components in first-line therapy for human immunodeficiency virus (HIV) infection. However, long-term treatment with existing NRTIs can be associated with significant toxic side effects and the emergence of drug-resistant strains. The identification of new NRTIs for the continued management of HIV-infected people therefore is paramount. In this report, we describe the response of a primary isolate of simian immunodeficiency virus (SIV) to 4′-ethynyl-2-fluoro-2′-deoxyadenosine (EFdA) both
in vitro
and
in vivo
. EFdA was 3 orders of magnitude better than tenofovir (TFV), zidovudine (AZT), and emtricitabine (FTC) in blocking replication of SIV in monkey peripheral blood mononuclear cells (PBMCs)
in vitro
, and in a preliminary study using two SIV-infected macaques with advanced AIDS, it was highly effective at treating SIV infection and AIDS symptoms
in vivo
. Both animals had 3- to 4-log decreases in plasma virus burden within 1 week of EFdA therapy (0.4 mg/kg of body weight, delivered subcutaneously twice a day) that eventually became undetectable. Clinical signs of disease (diarrhea, weight loss, and poor activity) also resolved within the first month of treatment. No detectable clinical or pathological signs of drug toxicity were observed within 6 months of continuous therapy. Virus suppression was sustained until drug treatment was discontinued, at which time virus levels rebounded. Although the rebound virus contained the M184V/I mutation in the viral reverse transcriptase, EFdA was fully effective in maintaining suppression of mutant virus throughout the drug treatment period. These results suggest that expanded studies with EFdA are warranted.
Dynamic Longitudinal Antibody Responses during Borrelia burgdorferi Infection and Antibiotic Treatment of Rhesus Macaques
Authors: Embers Monica E. , Hasenkampf Nicole R. , Jacobs Mary B. , Philipp Mario T.
Published: June 2012

Infection withBorrelia burgdorferielicits robust yet disparate antibody responses in infected individuals. A longitudinal assessment of antibody responses to multiple diagnostic antigens following experimental infection and treatment has not previously been reported. Our goal was to identify a combination of antigens that could indicate infection at all phases of disease and response to antibiotic treatment. Because the rhesus macaque recapitulates the hallmark signs and disease course of human Lyme disease, we examined the specific antibody responses to multiple antigens ofB. burgdorferifollowing infection of macaques. Five macaques infected with strain B31 and 12 macaques infected with strain JD1 were included in the analysis. Approximately half of these animals were treated with antibiotics at 4 to 6 months postinoculation. Antibody responses to severalB. burgdorferirecombinant antigens, including OspC, DbpA, BBK32, OspA, and OppA-2, were measured at multiple points throughout infection. We have previously shown a decline in the response to the C6 peptide following antibiotic treatment. Responses to OspA and OspC, however, were variable over time among individuals, irrespective of antibiotic treatment. Not every individual responded to BBK32, but anti-DbpA IgG levels were uniformly high and remained elevated for all animals. All responded to OppA-2, with a decline posttreatment that was slow and incomplete. This is the first demonstration ofB. burgdorferiOppA-2 antigenicity in nonhuman primates. The combination of DbpA, OspC, OspA, and OppA-2 with the C6 diagnostic peptide has the potential to detect infection throughout all disease phases.
Beijing Sublineages of Mycobacterium tuberculosis Differ in Pathogenicity in the Guinea Pig
Authors: Kato-Maeda Midori , Shanley Crystal A. , Ackart David , Jarlsberg Leah G. , Shang Shaobin , Obregon-Henao Andres , Harton Marisabel , Basaraba Randall J. , Henao-Tamayo Marcela , Barrozo Joyce C. , Rose Jordan , Kawamura L. Masae , Coscolla Mireia , Fofanov Viacheslav Y. , Koshinsky Heather , Gagneux Sebastien , Hopewell Philip C. , Ordway Diane J. , Orme Ian M.
Published: June 2012

The Beijing family ofMycobacterium tuberculosisstrains is part of lineage 2 (also known as the East Asian lineage). In clinical studies, we have observed that isolates from the sublineage RD207 of lineage 2 were more readily transmitted among humans. To investigate the basis for this difference, we tested representative strains with the characteristic Beijing spoligotype from four of the five sublineages of lineage 2 in the guinea pig model and subjected these strains to comparative whole-genome sequencing. The results of these studies showed that all of the clinical strains were capable of growing and causing lung pathology in guinea pigs after low-dose aerosol exposure. Differences between the abilities of the four sublineages to grow in the lungs of these animals were not overt, but members of RD207 were significantly more pathogenic, resulting in severe lung damage. The RD207 strains also induced much higher levels of markers associated with regulatory T cells and showed a significant loss of activated T cells in the lungs over the course of the infections. Whole-genome sequencing of the strains revealed mutations specific for RD207 which may explain this difference. Based on these data, we hypothesize that the sublineages ofM. tuberculosisare associated with distinct pathological and clinical phenotypes and that these differences influence the transmissibility of particularM. tuberculosisstrains in human populations.
Evolution of Testing Algorithms at a University Hospital for Detection of Clostridium difficile Infections
Authors: Culbreath Karissa , Ager Edward , Nemeyer Ronald J. , Kerr Alan , Gilligan Peter H.
Published: June 2012

We present the evolution of testing algorithms at our institution in which the C. Diff Quik Chek Complete immunochromatographic cartridge assay determines the presence of both glutamate dehydrogenase and
Clostridium difficile
toxins A and B as a primary screen for
C. difficile
infection and indeterminate results (glutamate dehydrogenase positive, toxin A and B negative) are confirmed by the GeneXpert
C. difficile
PCR assay. This two-step algorithm is a cost-effective method for highly sensitive detection of toxigenic
C. difficile
.
Performance of BinaxNOW for Diagnosis of Malaria in a U.S. Hospital
Authors: DiMaio Michael A. , Pereira Irma T. , George Tracy I. , Banaei Niaz
Published: June 2012

Microscopic diagnosis and species identification of
Plasmodium
in areas of nonendemicity provide a robust method for malaria diagnosis but are technically challenging. A prospective study was conducted to measure the performance of BinaxNOW compared to microscopy (the gold standard) in a U.S. teaching hospital. Overall, BinaxNOW was 84.2% sensitive and 99.8% specific. Excluding patients on antimalarial therapy, the sensitivity was 92.9%. Importantly, BinaxNOW initially misclassified a case of
Plasmodium falciparum
malaria as non-
falciparum
. These results support the judicious use of BinaxNOW in screening of individuals suspected of having malaria in areas of nonendemicity.
Proteome-Wide Overexpression of Host Proteins for Identification of Factors Affecting Tombusvirus RNA Replication: an Inhibitory Role of Protein Kinase C
Authors: Shah Nawaz-ul-Rehman Muhammad , Martinez-Ochoa Natalia , Pascal Helene , Sasvari Zsuzsanna , Herbst Christin , Xu Kai , Baker Jannine , Sharma Monika , Herbst Alan , Nagy Peter D.
Published: June 2012

To identify host genes affecting replication of
Tomato bushy stunt virus
(TBSV), a small model positive-stranded RNA virus, we overexpressed 5,500 yeast proteins individually in
Saccharomyces cerevisiae
, which supports TBSV replication. In total, we identified 141 host proteins, and overexpression of 40 of those increased and the remainder decreased the accumulation of a TBSV replicon RNA. Interestingly, 36 yeast proteins were identified previously by various screens, greatly strengthening the relevance of these host proteins in TBSV replication. To validate the results from the screen, we studied the effect of protein kinase C1 (Pkc1), a conserved host kinase involved in many cellular processes, which inhibited TBSV replication when overexpressed. Using a temperature-sensitive mutant of Pkc1p revealed a high level of TBSV replication at a semipermissive temperature, further supporting the idea that Pkc1p is an inhibitor of TBSV RNA replication. A direct inhibitory effect of Pkc1p was shown in a cell-free yeast extract-based TBSV replication assay, in which Pkc1p likely phosphorylates viral replication proteins, decreasing their abilities to bind to the viral RNA. We also show that cercosporamide, a specific inhibitor of Pkc-like kinases, leads to increased TBSV replication in yeast, in plant single cells, and in whole plants, suggesting that Pkc-related pathways are potent inhibitors of TBSV in several hosts.
Mammalian Innate Resistance to Highly Pathogenic Avian Influenza H5N1 Virus Infection Is Mediated through Reduced Proinflammation and Infectious Virus Release
Authors: Nelli Rahul K. , Dunham Stephen P. , Kuchipudi Suresh V. , White Gavin A. , Baquero-Perez Belinda , Chang Pengxiang , Ghaemmaghami Amir , Brookes Sharon M. , Brown Ian H. , Chang Kin-Chow
Published: June 2012

Respiratory epithelial cells and macrophages are the key innate immune cells that play an important role in the pathogenesis of influenza A virus infection. We found that these two cell types from both human and pig showed comparable susceptibilities to initial infection with a highly pathogenic avian influenza (HPAI) H5N1 virus (A/turkey/Turkey/1/05) and a moderately pathogenic human influenza H1N1 virus (A/USSR/77), but there were contrasting differences in host innate immune responses. Human cells mounted vigorous cytokine (tumor necrosis factor alpha [TNF-α] and interleukin-6 [IL-6]) and chemokine (CXCL9, CXCL10, and CXCL11) responses to H5N1 virus infection. However, pig epithelial cells and macrophages showed weak or no TNF-α and chemokine induction with the same infections. The apparent lack of a strong proinflammatory response, corroborated by the absence of TNF-α induction in H5N1 virus-challenged pigs, coincided with greater cell death and the reduced release of infectious virus from infected pig epithelial cells. Suppressor of cytokine signaling 3 (SOCS3), a protein suppressor of the JAK-STAT pathway, was constitutively highly expressed and transcriptionally upregulated in H5N1 virus-infected pig epithelial cells and macrophages, in contrast to the corresponding human cells. The overexpression of SOCS3 in infected human macrophages dampened TNF-α induction. In summary, we found that the reported low susceptibility of pigs to contemporary Eurasian HPAI H5N1 virus infections coincides at the level of innate immunity of respiratory epithelial cells and macrophages with a reduced output of viable virus and an attenuated proinflammatory response, possibly mediated in part by SOCS3, which could serve as a target in the treatment or prevention of virus-induced hypercytokinemia, as observed for humans.
Hepatitis B Virus Nucleocapsid but Not Free Core Antigen Controls Viral Clearance in Mice
Authors: Lin Yi-Jiun , Wu Hui-Lin , Chen Ding-Shinn , Chen Pei-Jer
Published: June 2012

We have recently shown that hepatitis B virus (HBV) core antigen (HBcAg) is the major viral factor for HBV clearance using a hydrodynamics-based mouse model. Knockout of HBcAg hampers the development of antiviral immune responses and thus promotes HBV persistence. Here, we further demonstrated that only in the capsid form, but not the free or dimer form, can HBcAg exert its contributory role in HBV clearance. HBcAg is the main structural protein of HBV icosahedral nucleocapsid. A mutant HBV DNA which expresses an assembly-defective HBcAg, HBcAgY132A, surprisingly prolonged HBV surface antigenemia in both C57BL/6 and BALB/c mice without affecting viral transcription and translation. This result was not due to a loss of the possible immune epitope caused by the single-amino-acid substitution of HBcAg. Moreover, the particular HBV mutant failed to induce robust humoral and cellular immunity against HBV. These data revealed the requirement of capsid structure for inducing adequate immunity that leads to HBV clearance in mice.
Functional Balance of the Hemagglutinin and Neuraminidase Activities Accompanies the Emergence of the 2009 H1N1 Influenza Pandemic
Authors: Xu Rui , Zhu Xueyong , McBride Ryan , Nycholat Corwin M. , Yu Wenli , Paulson James C. , Wilson Ian A.
Published: June 2012

The 2009 H1N1 influenza pandemic is the first human pandemic in decades and was of swine origin. Although swine are believed to be an intermediate host in the emergence of new human influenza viruses, there is still little known about the host barriers that keep swine influenza viruses from entering the human population. We surveyed swine progenitors and human viruses from the 2009 pandemic and measured the activities of the hemagglutinin (HA) and neuraminidase (NA), which are the two viral surface proteins that interact with host glycan receptors. A functional balance of these two activities (HA binding and NA cleavage) is found in human viruses but not in the swine progenitors. The human 2009 H1N1 pandemic virus exhibited both low HA avidity for glycan receptors as a result of mutations near the receptor binding site and weak NA enzymatic activity. Thus, a functional match between the hemagglutinin and neuraminidase appears to be necessary for efficient transmission between humans and may be an indicator of the pandemic potential of zoonotic viruses.
Analysis by Single-Gene Reassortment Demonstrates that the 1918 Influenza Virus Is Functionally Compatible with a Low-Pathogenicity Avian Influenza Virus in Mice
Authors: Qi Li , Davis A. Sally , Jagger Brett W. , Schwartzman Louis M. , Dunham Eleca J. , Kash John C. , Taubenberger Jeffery K.
Published: June 2012

The 1918-1919 “Spanish” influenza pandemic is estimated to have caused 50 million deaths worldwide. Understanding the origin, virulence, and pathogenic properties of past pandemic influenza viruses, including the 1918 virus, is crucial for current public health preparedness and future pandemic planning. The origin of the 1918 pandemic virus has not been resolved, but its coding sequences are very like those of avian influenza virus. The proteins encoded by the 1918 virus differ from typical low-pathogenicity avian influenza viruses at only a small number of amino acids in each open reading frame. In this study, a series of chimeric 1918 influenza viruses were created in which each of the eight 1918 pandemic virus gene segments was replaced individually with the corresponding gene segment of a prototypical low-pathogenicity avian influenza (LPAI) H1N1 virus in order to investigate functional compatibility of the 1918 virus genome with gene segments from an LPAI virus and to identify gene segments and mutations important for mammalian adaptation. This set of eight “7:1” chimeric viruses was compared to the parental 1918 and LPAI H1N1 viruses in intranasally infected mice. Seven of the 1918 LPAI 7:1 chimeric viruses replicated and caused disease equivalent to the fully reconstructed 1918 virus. Only the chimeric 1918 virus containing the avian influenza PB2 gene segment was attenuated in mice. This attenuation could be corrected by the single E627K amino acid change, further confirming the importance of this change in mammalian adaptation and mouse pathogenicity. While the mechanisms of influenza virus host switch, and particularly mammalian host adaptation are still only partly understood, these data suggest that the 1918 virus, whatever its origin, is very similar to avian influenza virus.
Glycosylation of Simian Immunodeficiency Virus Influences Immune-Tissue Targeting during Primary Infection, Leading to Immunodeficiency or Viral Control
Authors: Sugimoto Chie , Nakamura Shinichiro , Hagen Shoko I. , Tsunetsugu-Yokota Yasuko , Villinger Francois , Ansari Aftab A. , Suzuki Yasuo , Yamamoto Naoki , Nagai Yoshiyuki , Picker Louis J. , Mori Kazuyasu
Published: June 2012

Glycans of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) play pivotal roles in modulating virus-target cell interactions. We have previously reported that, whereas SIVmac239 is pathogenic, its deglycosylated essentially nonpathogenic mutant (Δ5G) serves as a live-attenuated vaccine, although both replicate similarly during primary infection. These findings prompted us to determine whether such a polarized clinical outcome was due to differences in the immune tissues targeted by these viruses, where functionally and phenotypically different memory CD4
+
T cells reside. The results showed that Δ5G replicates in secondary lymphoid tissue (SLT) at 1- to 2-log-lower levels than SIVmac239, whereas SIVmac239-infected but not Δ5G-infected animals deplete CXCR3
+
CCR5
+
transitional memory (TrM) CD4
+
T cells. An early robust Δ5G replication was localized to small intestinal tissue, especially the lamina propria (effector site) rather than isolated lymphoid follicles (inductive site) and was associated with the induction and depletion of CCR6
+
CXCR3
−
CCR5
+
effector memory CD4
+
T cells. These results suggest that differential glycosylation of Env dictates the type of tissue-resident CD4
+
T cells that are targeted, which leads to pathogenic infection of TrM-Th1 cells in SLT and nonpathogenic infection of Th17 cells in the small intestine, respectively.
The PDZ1 and PDZ3 Domains of MAGI-1 Regulate the Eight-Exon Isoform of the Coxsackievirus and Adenovirus Receptor
Authors: Kolawole Abimbola Olayinka , Sharma Priyanka , Yan Ran , Lewis Kyle Joseph Edward , Xu Zhigang , Hostetler Heather Ann , Ashbourne Excoffon Katherine Julie Diane
Published: June 2012

Epithelial integrity is essential for homeostasis and poses a formidable barrier to pathogen entry. Major factors for viral entry into epithelial cells are the localization and abundance of the primary receptor. The coxsackievirus and adenovirus receptor (CAR) is a primary receptor for these two pathogenic groups of viruses. In polarized epithelia, a low-abundance, alternatively spliced eight-exon isoform of CAR, CAR
Ex8
, is localized apically where it can support viral infection from the air-exposed surface. Using biochemical, cell biology, genetic, and spectroscopic approaches, we show that the levels of apical CAR
Ex8
are negatively regulated by the PDZ domain-containing protein MAGI-1 (membrane-associated guanylate kinase with inverted orientation protein-1) and that two MAGI-1 PDZ domains, PDZ1 and PDZ3, regulate CAR
Ex8
levels in opposing ways. Similar to full-length MAGI-1, expression of the isolated PDZ3 domain significantly reduces cell surface CAR
Ex8
abundance and adenovirus infection. In contrast, the PDZ1 domain is able to rescue CAR
Ex8
and adenovirus infection from MAGI-1-mediated suppression. These data suggest a novel cell-based strategy to either suppress viral infection or augment adenovirus-based gene therapy.
Geology and geochronology of Tlaloc, Telapón, Iztaccíhuatl, and Popocatépetl volcanoes, Sierra Nevada, central Mexico
Authors: Macías J.L. , Arce J.L. , García-Tenorio F. , Layer P.W. , Rueda H. , Reyes-Agustin G. , López-Pizaña F. , Avellán D.
Published: June 2012

The Sierra Nevada Volcanic Range includes, from south to north, the active Popocatépetl (5452 m), Iztaccíhuatl (5272 m) with several volcanic edifices, Telapón (4000 m), and Tlaloc (4150 m) volcanoes. It has been generally assumed that volcanic activity has migrated from Tlaloc (north) to Popocatépetl (south) over time. New evidence obtained from previous studies, field reconnaissance, and radiometric dating indicate that magmatism at the Sierra Nevada Volcanic Range likely started at 1.8–1.4 Ma with the construction of Paleo-Tlaloc volcano, which is today buried by younger deposits. The activity continued between 1.07 and 0.89 Ma with the emplacement of dacitic domes (Puico, Yahualica, Yeloxochitl, Tearco, and Torrecillas), lavas and associated pyroclastic flows as the San Francisco (1 Ma), and Chicoloapan (0.9 Ma). Afterwards, the main edifice of modern Tlaloc was built up through the emission of dacitic lava flows (0.94–0.84 Ma). Iztaccíhuatl began its activity ca. 1.1 Ma with the formation of several volcanic edifices up to 0.45 Ma, time during which a Mount St. Helens—type event destroyed the southeastern flank of Los Pies Recientes cone, producing a debris avalanche and pyroclastic deposits. Telapón volcano formed approximately between 0.38 Ma and 0.34 Ma ago with the emplacement of lava flows and a dome that become quiescent afterwards. Apparently, ca. 0.32 Ma, Popocatépetl began its eruptive activity that continues today. Strikingly, Tlaloc reawakened with the emission of rhyolitic magma at 0.129 Ma followed by the emplacement of the El Papayo dacite (118 ka) to the south and Téyotl summit lavas (80 ka). Activity continued at Tlaloc with the generation of five explosive eruptions at 44, 38, 33, 31, and 25 ka and the growth of the summit dome. Coevally, Popocatépetl, at the southern end of the range, had collapsed twice to the south and had intense volcanic activity up until today. Holocene activity has taken place at Iztaccíhuatl with the 9 ka Buenavista dacitic lava flow and repetitive Plinian eruptions of Popocaté-petl including some historic events and the 1994—present eruption. Popocatépetl's reawakening reminded authorities, scientists, media, and the public of its potential risk. In fact, on 22 January 2001, the rapid collapse of an eruptive column generated scoria-rich pyroclastic flows that partly melted the glacier producing lahars. From the above considerations it is obvious that magmatism of the Sierra Nevada Volcanic Range did not keep a continuous north to south migrating path, but it rather shifted back and forth chaotically throughout its evolution. It is worth mentioning that major gaps presented in the eruptive sequence are most likely due to poor radiometric coverage of the area that may improve in the future.
IntestinalStaphylococcus spp.and virulent features associated with coeliac disease
Authors: Sánchez Ester , Ribes-Koninckx Carmen , Calabuig Miguel , Sanz Yolanda
Published: June 2012

Aim

To determine whether intestinalStaphylococcus spp.and their pathogenic features differed between coeliac disease (CD) patients and healthy controls.

Methods

60 children, including active CD (n=20) and non-active CD (n=20) patients and healthy controls (n=20), were studied. Staphylococci were isolated from faeces and identified by PCR and DNA sequencing. The carriage of virulent genes, including adhesion (atlEandfbe), cell aggregation (icaD), global regulatory (agrandsar) and methicillin-resistant (mecA) genes, was analysed by PCR.

Results

Staphylococcusepidermidiswas more abundant in the microbiota of active and non-active CD patients than in controls.Staphylococcushaemolyticuswas more abundant in active CD patients than in control subjects.Staphylococcusaureuswas less abundant in active CD patients than in the other child groups.Staphylococcus spp.diversity was higher in active CD patients than in non-active CD patients and controls. The presence of themecAgene and the simultaneous presence of both themecAandatlEgenes were higher inS. epidermidisclones isolated from CD patients, with active and non-active disease, than in those from control subjects. The individual presence of the other virulent genes was lower inS. epidermidisfrom active CD patients than in those from the other -child- groups.

Conclusions

Increased abundance ofS. epidermidiscarrying themecAgene, in active and non-active CD patients, most likely reflects increased exposure of these subjects to opportunistic pathogens and antimicrobials.