bluuebunny/crossref_metadata_2025 huggingface dataset:
Single‐cell RNA sequencing: revealing human pre‐implantation development, pluripotency and germline development
Authors: Petropoulos S. , Panula S. P. , Schell J. P. , Lanner F.
Published: April 2016

Early human development is a dynamic, heterogeneous, complex and multidimensional process. During the first week, the single‐cell zygote undergoes eight to nine rounds of cell division generating the multicellular blastocyst, which consists of hundreds of cells forming spatially organized embryonic and extra‐embryonic tissues. At the level of transcription, degradation of maternal RNA commences at around the two‐cell stage, coinciding with embryonic genome activation. Although numerous efforts have recently focused on delineating this process in humans, many questions still remain as thorough investigation has been limited by ethical issues, scarce availability of human embryos and the presence of minute amounts of DNA and RNA. In vitro cultures of embryonic stem cells provide some insight into early human development, but such studies have been confounded by analysis on a population level failing to appreciate cellular heterogeneity. Recent technical developments in single‐cell RNA sequencing have provided a novel and powerful tool to explore the early human embryo in a systematic manner. In this review, we will discuss the advantages and disadvantages of the techniques utilized to specifically investigate human development and consider how the technology has yielded new insights into pre‐implantation development, embryonic stem cells and the establishment of the germ line.
The Effects of Receptacle on the Expected Flavor of a Colored Beverage: Cross‐Cultural Comparison Among French, Japanese, and Norwegian Consumers
Authors: Wan Xiaoang , Woods Andy T. , Jacquot Muriel , Knoeferle Klemens , Kikutani Mariko , Spence Charles
Published: April 2016

The present online study was designed to investigate whether the expected flavor associated with a colored beverage is affected by the type of receptacle in which the drink is presented. More than 400 participants from France, Japan and Norway viewed photographs of red, green, yellow, blue, orange, brown and clear beverages presented in a water glass, a wine glass, a cocktail glass or a plastic cup. They had to indicate the first flavor that came to mind by choosing a flavor from a list of 24 options, and to rate the familiarity and pleasantness of each drink. The results revealed that the nature of the receptacle modulated the meaning (expected flavor) of color for the red, green, yellow, blue and orange drinks. Cultural differences were observed in terms of the expected flavor elicited by the blue drinks, as well as how different receptacles influenced the familiarity and pleasantness ratings of the same drinks.

Practical Applications

The present study provides a better understanding of the crossmodal correspondences observed in the case of beverages. We demonstrate how the type of receptacle, an important but all too frequently neglected contextual factor, influences the expected flavor elicited by color. These findings regarding crossmodal correspondences are relevant to sensory scientists interested in the flavor‐color associations of beverages. What is more, our results also reveal cross‐cultural differences in the perception of beverages, and demonstrate how associations that people in certain countries/cultures may take for granted could be very surprising or novel in other cultures/countries. Specially, the present study provides new evidence concerning how people from France and Japan (both of which are well known for their unique and distinctive food cultures) would respond to the same colored drinks in similar or different ways to other groups of people (who have been tested in the present or previous research). Therefore, our findings are also important in terms of international marketing, and highlight the importance of getting the receptacle right when displaying a beverage in online marketing.
Effects of Piper sarmentosum extract on the growth performance, antioxidant capability and immune response in weaned piglets
Authors: Wang D. F. , Zhou L. L. , Zhou H. L. , Hou G. Y. , Zhou X. , Li W.
Published: April 2016

The biological properties of Piper sarmentosum render it a potential substitute for antibiotics in livestock feed. This study evaluated the effects of P. sarmentosum extract (PSE) on the growth performance, antioxidant capability and immune response of weaned piglets. Eighty 21‐d‐old weaned piglets were selected and randomly allocated to one of four dietary treatments with five replicates of four pigs each. The dietary treatments consisted of a basal diet supplemented with 0 (T0), 50 (T50), 100 (T100) or 200 (T200) mg/kg PSE. The feeding trial lasted 4 weeks. The results revealed that the T50 group had the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the feeding trial (p < 0.05). Additionally, the T50 group had higher (p < 0.05) serum glutathione peroxidase activity (GSH‐Px) and lower (p < 0.05) serum malondialdehyde (MDA) levels than the T0 group at 4 weeks post‐weaning (p < 0.05). Serum levels of interleukin‐1β (IL‐1β) and tumour necrosis factor‐α (TNF‐α) decreased, while serum levels of interleukin‐4 (IL‐4), interleukin‐10 (IL‐10) and transforming growth factor‐β (TGF‐β) increased by PSE supplementation at 4 weeks post‐weaning (p < 0.05). PSE supplementation upregulated the mRNA expression of IL‐4, IL‐10 and TGF‐β and downregulated the mRNA expression of TNF‐α, IL‐1β and interleukin‐6 (IL‐6) in the ileal mucosal layer of piglets (p < 0.05). In summary, our study findings revealed that PSE supplementation improved the antioxidant capability, and reduced inflammation, which may be beneficial to weaned piglet health.
Atypical Fibroxanthoma in a 13‐Year‐Old Guatemalan Girl with Xeroderma Pigmentosum
Authors: Chappell Ava G. , Chase Elizabeth P. , Chang Beverly , Cunningham Eric , Mihm Fred , Calame Antoanella , Fudem Gary , Cunningham Bari
Published: April 2016

Xeroderma pigmentosum (XP) is a rare, autosomal recessive disease involving a defect in DNA repair leading to the premature development of numerous aggressive cutaneous malignancies. Although atypical fibroxanthoma (AFX) is a neoplasm typically found in the setting of extensive sun exposure or therapeutic radiation, AFXs are rarely associated with children with XP. We report the case of a 13‐year‐old Guatemalan girl with the XP type C variant who developed one of the largest AFXs reported on a child's finger.
Periodontal diseases as a source of halitosis: a review of the evidence and treatment approaches for dentists and dental hygienists
Authors: De Geest Sophie , Laleman Isabelle , Teughels Wim , Dekeyser Christel , Quirynen Marc
Published: April 2016

Bad breath (halitosis) is an important social complaint. In most cases (≥90%), the cause of halitosis can be found within the oral cavity. Under this circumstance, the term oral malodor applies. It affects both healthy and periodontally diseased individuals. Oral malodor is mainly caused by a microbial degradation of both sulfur‐containing and nonsulfur‐containing amino acids into volatile, bad‐smelling gases. Anaerobic gram‐negative bacteria, the same species that have been linked to periodontal diseases, are especially involved in this process, explaining why clinicians often associate oral malodor with periodontitis. Some volatile organic compounds render patients more susceptible to periodontitis and this supports the malodor–periodontitis link. This review investigates the interaction between oral malodor and periodontal diseases. Pro and con arguments regarding the mechanisms of halitosis and clinical implications will be presented. In general, however, the impact of tongue coatings has been found to be the dominant factor, besides gingivitis and periodontitis. The last part of this review discusses the treatment of bad breath, with different options.
Polymorphonuclear neutrophils in periodontitis and their possible modulation as a therapeutic approach
Authors: Nicu Elena A. , Loos Bruno G.
Published: April 2016

The main focus of this review is polymorphonuclear neutrophilic granulocytes. Polymorphonuclear neutrophils play a pivotal role in normal host resistance to subgingival dental‐plaque biofilm. Both hyper‐ and hypo‐responsiveness of the immune system toward the microbial challenge in periodontitis have been described. We review polymorphonuclear neutrophil physiology with emphasis on the role of neutrophil functions and dysfunctions in periodontitis. Text boxes are given at the end of each subsection, which present the current knowledge on neutrophil‐modulating agents as a potential therapeutic approach in periodontitis.
Antibiotics/antimicrobials: systemic and local administration in the therapy of mild to moderately advanced periodontitis
Authors: Jepsen Karin , Jepsen Søren
Published: April 2016

This review gives an update of the current scientific evidence on the efficacy of the adjunctive use of systemic and local antibiotics/antimicrobials in the treatment of periodontitis. In particular, it addresses whether their use can improve the results of nonsurgical mechanical therapy in mild‐to‐moderate forms of the disease. Large numbers of randomized clinical trials and systematic reviews with meta‐analyses have clearly established that adjunctive systemic antibiotics, combined with mechanical debridement, offer clinical improvements additional to those obtained with scaling and root planing alone. These effects are more pronounced in aggressive periodontitis and in initially deep pockets, whereas more limited additional improvements, of 0.3 mm for additional pocket reduction and 0.2 mm for additional clinical attachment gain, have been documented for moderately deep sites (4–6 mm) in patients with chronic periodontitis. The marginal clinical benefit in patients with moderate disease has to be balanced against possible side effects. Notably, it has to be realized that an increasing number of warnings have been articulated against the unrestricted use of antibiotics in treating periodontal diseases because of the emerging global public health issue of bacterial resistance. The effects of the adjunctive local administration of antimicrobials have also been very well documented in several systematic reviews. Overall, in persistent or recurrent localized deep sites, the application of antimicrobials by sustained‐delivery devices may offer a benefit of an additional 0.4 mm in pocket depth reduction and 0.3 mm in clinical attachment level gain. In conclusion, the slight additional benefits of adjunctive antimicrobials, which were shown for moderate forms of periodontitis, have to be balanced against their side effects and therefore their prescription should be limited as much as possible.
Supporting Middle School Teachers’ Implementation of STEM Design Challenges
Authors: Lesseig Kristin , Nelson Tamara Holmlund , Slavit David , Seidel Ryan August
Published: April 2016

We describe and analyze a professional development (PD) model that involved a partnership among science, mathematics and education university faculty, science and mathematics coordinators, and middle school administrators, teachers, and students. The overarching project goal involved the implementation of interdisciplinary STEM Design Challenges (DCs). The PD model targeted: (a) increasing teachers’ content and pedagogical content knowledge in mathematics and science; (b) helping teachers integrate STEM practices into their lessons; and (c) addressing teachers’ beliefs about engaging underperforming students in challenging problems. A unique aspect involved low‐achieving students and their teachers learning alongside each other as they co‐participated in STEM design challenges for one week in the summer. Our analysis focused on what teachers came to value about STEM DCs, and the challenges in and affordances for implementing DCs. Two significant areas of value for the teachers were students’ use of scientific, mathematical, and engineering practices and motivation, engagement, and empowerment by all learners. Challenges associated with pedagogy, curriculum, and the traditional structures of the schools were identified. Finally, there were four key affordances: (a) opportunities to construct a vision of STEM education; (b) motivation to implement DCs; (c) ambitious pedagogical tools; and, (d) ongoing support for planning and implementation.

This article features a Research to Practice Companion Article. Please click on the supporting information link below to access.
Eltrombopag after allogeneic haematopoietic cell transplantation in a case of poor graft function and systematic review of the literature
Authors: Dyba J. , Tinmouth A. , Bredeson C. , Matthews J. , Allan D. S.
Published: April 2016

Background

Late graft failure after allogeneic haematopoietic cell transplantation (HCT) can result from the failed engraftment of long‐term engrafting cells. The use of thrombopoietin (TPO) receptor agonists (TRA) has been extensively studied and remains an important component of experimental ex vivo stem cell expansion protocols, but its use in allogeneic transplantation is still evolving.

Methods

We describe the use of eltrombopag, a TRA, to stimulate the rescue of late graft failure in a patient following allogeneic HCT, and we performed a systematic review of published studies describing the use of TRAs following allogeneic transplantation.

Results

A total of eight publications were identified from our systematic search and included observational case studies (five studies, total of seven patients) that primarily addressed ITP or isolated thrombocytopenia at various time points after allogeneic HCT and prospective clinical trials (three studies, total of 177 patients with 95 patients receiving TRAs). No studies reported specifically on the use of TRAs for the treatment of trilineage graft failure as a means of in vivo stem cell expansion. The use of TRAs following allogeneic HCT appears safe and promising.

Conclusion

The use of eltrombopag or other TRAs to treat poor graft function after allogeneic HCT is intriguing and warrants further study.
Improve effluent water quality at Abu‐Rawash wastewater treatment plant with the application of coagulants
Authors: Mostafa Mohamed K. , Peters Robert W.
Published: April 2016

This research investigated a process to improve the Abu‐Rawash WWTP effluent water quality with the application of aluminum chloride (AlCl3); in turn, this improvement will lead to improve water quality at the El‐Rahawy drain and in the Rosetta branch of the Nile River. Sewage samples were collected from the effluent of the grit removal chamber. Jar tests were performed to estimate the coagulant dosage required to obtain acceptable treatment. To prove the efficiency of the AlCl3 in wastewater treatment, a comparison was conducted between AlCl3 and other common coagulants used in wastewater treatment which include ferrous sulfate (FeSO4), ferric sulfate (Fe2(SO4)3) and ferric chloride (FeCl3). Results showed AlCl3 was more cost‐effective and efficient in wastewater treatment than these three iron‐based coagulants. A paired‐sample t‐test was also performed to rank the performance of the various coagulants tested. The t‐test has also confirmed that the AlCl3 has the highest performance over those coagulants.
The value of rural landscape in Aquitania (Colombia): application of spatial hedonic models in real estate analysis
Authors: Plata Fajardo Ana Milena , Cañón Julio , Lafortezza Raffaele
Published: April 2016

This study addresses the marginal economic value of environmental amenities, structural characteristics, neighborhood facilities, and accessibility on property in Aquitania - Colombia. Based on 400 assessed values of rural land property and on 21 characteristic variables of land amenities and facilities, the study compares three models: Ordinary Least Squares (ols), Spatial Lag Model (slm), and Spatial Error Model (sem). Results show that both slm and sem outperformed ols in identifying the significance of real estate attributes. Results shows that farmers value environmental amenities more than other attributes, being implicit the greater value of cattle over agriculture (onion) in land use. These models may help to support decisions in rural real estate economics.
National Synchrotron Light Source II storage ring vacuum systems
Authors: Hseuh Hsiao-Chaun , Hetzel Charles , Leng Shuwei , Wilson King , Xu Huijuan , Zigrosser Douglas
Published: April 2016

The National Synchrotron Light Source II, completed in 2014, is a 3-GeV synchrotron radiation (SR) facility at Brookhaven National Laboratory and has been in steady operation since. With a design electron current of 500 mA and subnanometer radians horizontal emittance, this 792-m circumference storage ring is providing the highest flux and brightness x-ray beam for SR users. The majority of the storage ring vacuum chambers are made of extruded aluminium. Chamber sections are interconnected using low-impedance radiofrequency shielded bellows. SR from the bending magnets is intercepted by water-cooled compact photon absorbers resided in the storage ring chambers. This paper presents the design of the storage ring vacuum system, the fabrication of vacuum chambers and other hardware, the installation, the commissioning, and the continuing beam conditioning of the vacuum systems.
Sport Consumer Behavior Research: Improving Our Game
Authors: Funk Daniel , Lock Daniel , Karg Adam , Pritchard Mark
Published: April 2016

Sport consumer behavior (SCB) research continues to grow in both popularity and sophistication. A guiding principle in much of this research has focused on the nature of sport-related experiences and the benefits sport consumers derive from these experiences. This emphasis has generated new knowledge and insights into the needs and wants of sport consumers. Although these efforts have contributed to the field’s understanding of SCB, the vast majority of this research has centered on psychological phenomena and the evaluative and affective components of these sport experiences. Approaches to this work have also narrowed, with SCB research predominately relying on cross-sectional studies and attitudinal surveys to collect information. This has resulted in limited findings that seldom account for how various situational or environmental factors might influence attitudinal data patterns at the individual and group level. This special issues seeks to deepen our understanding of SCB by providing seven papers that demonstrate or validate findings using multiple studies or data collections.
Hemodynamic, Hematological, and Hormonal Responses to Submaximal Exercise in Normobaric Hypoxia in Pubescent Girls
Authors: Park Hun-young , Nam Sang-seok , Tanaka Hirofumi , Lee Dong-jun
Published: April 2016

Purpose:

The aim of this study was to investigate hemodynamic, hematological, and immunological responses to prolonged submaximal cycle ergometer exercise at a simulated altitude of 3000 m in pubescent girls.

Methods:

Ten girls, 12.8 ± 1.0 years old, exercised on a cycle ergometer for 60 min at a work rate corresponding to 50% maximal oxygen consumption measured at sea level, under two environmental conditions; sea level (normoxia) and a simulated 3000 m altitude (normobaric hypoxia).

Results:

There were no significant differences in tidal volume, ventilation, oxygen consumption, cardiac output, stroke volume, and heart rate between the two exercise conditions. However, reticulocyte, adrenocorticotropic hormone, and cortisol concentrations increased significantly from pre- to postexercise in the hypoxic environment. Leukocyte and T-cell count increased and B-cell count decreased after exercise under both conditions. There were no significant changes in natural killer cell count.

Conclusion:

Our simulated hypoxic environment provided a mild environmental stressor that did not impose a heavy burden on the cardiovascular, hematological, or immunological functions during submaximal exercise in pubescent girls.
Maturity, Physical Ability, Technical Skill and Coaches’ Perception of Semi-Elite Adolescent Australian Footballers
Authors: Cripps Ashley J. , Hopper Luke , Joyce Christopher
Published: April 2016

Purpose:

To confirm the effect of maturational differences on anthropometric and physical testing and explore the effect of maturation on technical skill and coaches’ perceptions of skill in adolescent Australian footballers.

Methods:

Athletes were recruited from a semielite under 16 competition (n = 94, age 15.7 ± 0.3 years) and completed anthropometric, physical, and technical skill tests. Coaches from each team provided subjective ratings of athletes’ technical skills. Maturation groups were derived from years from peak height velocity estimates, with classifications either later, average or earlier maturing.

Results:

Effect size comparisons revealed very large to moderate effects between groups for anthropometric measures and performance in sprint and jump tasks. Small to moderate effects were reported between groups for coaches’ perceptions of skill, with the earlier maturing group perceived to have better overall technical skills, marking and ball winning abilities. Small to trivial effects were reported for performance in the technical skill tests.

Conclusion:

Despite no differences in skill tests, earlier maturing athletes may be afforded significant selection and competition advantages due to advanced physical capacities and coaches’ perceptions of skill.
Asymmetry During Maximal Sprint Performance in 11- to 16-Year-Old Boys
Authors: Meyers Robert W. , Oliver Jon L. , Hughes Michael G. , Lloyd Rhodri S. , Cronin John B.
Published: April 2016

Purpose:

The aim of this study was to examine the influence of age and maturation upon magnitude of asymmetry in the force, stiffness and the spatiotemporal determinants of maximal sprint speed in a large cohort of boys.

Methods:

344 boys between the ages of 11 and 16 years completed an anthropometric assessment and a 35 m sprint test, during which sprint performance was recorded via a ground-level optical measurement system. Maximal sprint velocity, as well as asymmetry in spatiotemporal variables, modeled force and stiffness data were established for each participant. For analysis, participants were grouped into chronological age, maturation and percentile groups.

Results:

The range of mean asymmetry across age groups and variables was 2.3–12.6%. The magnitude of asymmetry in all the sprint variables was not significantly different across age and maturation groups (p > .05), except relative leg stiffness (p < .05). No strong relationships between asymmetry in sprint variables and maximal sprint velocity were evident (rs < .39).

Conclusion:

These results provide a novel benchmark for the expected magnitude of asymmetry in a large cohort of uninjured boys during maximal sprint performance. Asymmetry in sprint performance is largely unaffected by age or maturation and no strong relationships exist between the magnitude of asymmetry and maximal sprint velocity.
Inhibition of class I histone deacetylases blunts cardiac hypertrophy through TSC2-dependent mTOR repression
Authors: Morales Cyndi R. , Li Dan L. , Pedrozo Zully , May Herman I. , Jiang Nan , Kyrychenko Viktoriia , Cho Geoffrey W. , Kim Soo Young , Wang Zhao V. , Rotter David , Rothermel Beverly A. , Schneider Jay W. , Lavandero Sergio , Gillette Thomas G. , Hill Joseph A.
Published: April 2016

HDAC inhibitors prevent pathological cardiac hypertrophy by suppressing a growth-promoting kinase.
Defining the stoichiometry of inositol 1,4,5-trisphosphate binding required to initiate Ca
2+
release
Authors: Alzayady Kamil J. , Wang Liwei , Chandrasekhar Rahul , Wagner Larry E. , Van Petegem Filip , Yule David I.
Published: April 2016

Four IP
3
molecules are needed to activate the IP
3
receptor.
Papers of note in
Science
Authors: VanHook Annalisa M.
Published: April 2016

This week’s articles identify hypoxia as a potential therapy for mitochondrial disease; present a programming language for designing synthetic biological circuits; and highlight several mechanisms that regulate inflammation, including parasites, long noncoding RNAs, and necrosis.
Paper of note in
Science Advances
Authors: VanHook Annalisa M.
Published: April 2016

This week’s article highlights how DNA released from adipocytes stimulates inflammation in adipose tissue.
B cells fuel pancreatic cancer
Authors: Ferrarelli Leslie K.
Published: April 2016

Targeting B cells may slow the inflammatory progression of pancreatic cancer.
Validation of Computational Approaches for Antiretroviral Dose Optimization
Authors: Siccardi Marco , Dickinson Laura , Owen Andrew
Published: April 2016

Strategies for reducing antiretroviral doses and drug costs can support global access, and numerous options are being investigated. Efavirenz pharmacokinetic simulation data generated with a bottom-up physiologically based model were successfully compared with data obtained from the ENCORE (Exercise and Nutritional Interventions for Cardiovascular Health) I clinical trial (efavirenz at 400 mg once per day versus 600 mg once per day). These findings represent a pivotal paradigm for the prediction of pharmacokinetics resulting from dose reductions. Validated computational models constitute a valuable resource for optimizing therapeutic options and predicting complex clinical scenarios.
Single- and Repeated-Dose Pharmacokinetics of Ceftaroline in Plasma and Soft Tissues of Healthy Volunteers for Two Different Dosing Regimens of Ceftaroline Fosamil
Authors: Matzneller Peter , Lackner Edith , Lagler Heimo , Wulkersdorfer Beatrix , Österreicher Zoe , Zeitlinger Markus
Published: April 2016

Ceftaroline fosamil (CPT-F) is currently approved for use for the treatment of complicated skin and soft tissue infections and community-acquired pneumonia at 600 mg twice daily (q12h), but other dosing regimens are under evaluation. To date, very limited data on the soft tissue pharmacokinetics (PK) of the active compound, ceftaroline (CPT), are available. CPT concentrations in the plasma, muscle, and subcutis of 12 male healthy volunteers were measured by microdialysis after single and repeated intravenous administration of 600 mg CPT-F q12h or three times daily (q8h) in two groups of 6 subjects each. Relevant PK and PK/pharmacodynamic (PD) parameters were calculated and compared between groups. In plasma, the area under the concentration-time curve (AUC) from 0 to 24 h for total CPT and the cumulative percentage of the dosing interval during which the free drug concentrations exceeded the MIC (
fT
MIC
) for unbound CPT for the currently established threshold of 1 mg/liter were significantly higher in the group receiving CPT-F q8h. Exposure to free drug in soft tissues was higher in the group receiving CPT-F q8h, but high interindividual variability in relevant PK parameters was observed. The mean ratios of the AUC from time zero to the end of the dosing interval (AUC
0-τ
) for free CPT in soft tissues and the AUC
0-τ
for the calculated free fraction in plasma at steady state ranged from 0.66 to 0.75. Administration of CPT-F q8h led to higher levels of drug exposure in all investigated compartments. When MIC values above 1 mg/liter were assumed, the calculated
fT
MIC
after dosing q12h was markedly lower than that after dosing q8h. The clinical implications of these differences are discussed in light of recently completed clinical phase III and PK/PD studies.
Results from the Solithromycin International Surveillance Program (2014)
Authors: Farrell David J. , Flamm Robert K. , Sader Helio S. , Jones Ronald N.
Published: April 2016

Solithromycin, a fourth-generation macrolide (a fluoroketolide with enhanced activity against macrolide-resistant bacteria due to interaction with three ribosomal sites) and the first fluoroketolide, was tested against a 2014 collection of 6,115 isolates, including
Streptococcus pneumoniae
(1,713 isolates),
Haemophilus influenzae
(1,308),
Moraxella catarrhalis
(577),
Staphylococcus aureus
(1,024), and beta-hemolytic streptococci (1,493), by reference broth microdilution methods. The geographic samples included 2,748 isolates from the United States, 2,536 from Europe, 386 from Latin America, and 445 from the Asia-Pacific region. Solithromycin was observed to be very active against
S. pneumoniae
(MIC
50/90
, 0.008/0.12 μg/ml), demonstrating 2-fold greater activity than telithromycin (MIC
50/90
, 0.015/0.25 μg/ml) and 16- to >256-fold greater activity than azithromycin (MIC
50/90
, 0.12/>32 μg/ml), with all strains being inhibited at a solithromycin MIC of ≤1 μg/ml. Against
H. influenzae
, solithromycin showed potency identical to that of telithromycin (MIC
50/90
, 1/2 μg/ml), and both of these compounds were 2-fold less active than azithromycin (MIC
50/90
, 0.5/1 μg/ml). All but one of the
M. catarrhalis
isolates were inhibited by solithromycin at ≤0.25 μg/ml. Solithromycin inhibited 85.3% of
S. aureus
isolates at ≤1 μg/ml, and its activity was lower against methicillin-resistant (MIC
50/90
, 0.06/>32 μg/ml) than against methicillin-susceptible (MIC
50/90
, 0.06/0.06 μg/ml) isolates. Little variation in solithromycin activity was observed by geographic region for the species tested. Solithromycin was very active against beta-hemolytic streptococci (MIC
50/90
, 0.015/0.03 μg/ml), and all isolates were inhibited at MIC values of ≤0.5 μg/ml. In conclusion, solithromycin demonstrated potent activity against global and contemporary (2014) pathogens that represent the major causes of community-acquired bacterial pneumonia. These data support the continued clinical development of solithromycin for the treatment of this important indication.
Topical Tenofovir Disoproxil Fumarate Nanoparticles Prevent HIV-1 Vaginal Transmission in a Humanized Mouse Model
Authors: Destache Christopher J. , Mandal Subhra , Yuan Zhe , Kang Guobin , Date Abhijit A. , Lu Wuxun , Shibata Annemarie , Pham Rachel , Bruck Patrick , Rezich Michael , Zhou You , Vivekanandan Renuga , Fletcher Courtney V. , Li Qingsheng
Published: April 2016

Preexposure prophylaxis (PrEP) with 1% tenofovir (TFV) vaginal gel has failed in clinical trials. To improve TFV efficacy in vaginal gel, we formulated tenofovir disoproxil fumarate nanoparticles in a thermosensitive (TMS) gel (TDF-NP-TMS gel). TDF-NPs were fabricated using poly(lactic-co-glycolic acid) (PLGA) polymer and an ion-pairing agent by oil-in-water emulsification. The efficacy of TDF-NP-TMS gel was tested in humanized bone marrow-liver-thymus (hu-BLT) mice. Hu-BLT mice in the treatment group (Rx;n= 15) were administered TDF-NP-TMS gel intravaginally, having TDF at 0.1%, 0.5%, and 1% (wt/vol) concentrations, whereas the control (Ctr;n= 8) group received a blank TMS gel. All Rx mice (0.1% [n= 4], 0.5% [n= 6], and 1% [n= 5]) were vaginally challenged with two transmitted/founder (T/F) HIV-1 strains (2.5 × 10550% tissue culture infectious doses). Rx mice were challenged at 4 h (0.1%), 24 h (0.5%), and 7 days (1%) posttreatment (p.t.) and Ctr mice were challenged at 4 h p.t. Blood was drawn weekly for 4 weeks postinoculation (p.i.) for plasma viral load (pVL) using reverse transcription-quantitative PCR. Ctr mice had positive pVL within 2 weeks p.i. Rx mice challenged at 4 h and 24 h showed 100% protection and no detectable pVL throughout the 4 weeks of follow-up (P= 0.009; Mantel-Cox test). Mice challenged at 7 days were HIV-1 positive at 14 days p.i. Further, HIV-1 viral RNA (vRNA) in vaginal and spleen tissues of Rx group mice with negative pVL were examined using anin situhybridization (ISH) technique. The detection of vRNA was negative in all Rx mice studied. The present studies elucidate TDF-NP-TMS gel as a long-acting, coitus-independent HIV-1 vaginal protection modality.
Oxadiazoles Have Butyrate-Specific Conditional Activity against Mycobacterium tuberculosis
Authors: Early Julie V. , Casey Allen , Martinez-Grau Maria Angeles , Gonzalez Valcarcel Isabel C. , Vieth Michal , Ollinger Juliane , Bailey Mai Ann , Alling Torey , Files Megan , Ovechkina Yulia , Parish Tanya
Published: April 2016

Mycobacterium tuberculosis
is a global pathogen of huge importance which can adapt to several host niche environments in which carbon source availability is likely to vary. We developed and ran a phenotypic screen using butyrate as the sole carbon source to be more reflective of the host lung environment. We screened a library of ∼87,000 small compounds and identified compounds which demonstrated good antitubercular activity against
M. tuberculosis
grown with butyrate but not with glucose as the carbon source. Among the hits, we identified an oxadiazole series (six compounds) which had specific activity against
M. tuberculosis
but which lacked cytotoxicity against mammalian cells.
Murine Model for Preclinical Studies of Var2CSA-Mediated Pathology Associated with Malaria in Pregnancy
Authors: de Moraes Luciana V. , Dechavanne Sebastien , Sousa Patrícia M. , Barateiro André , Cunha Sónia F. , Nunes-Silva Sofia , Lima Flávia A. , Murillo Oscar , Marinho Claudio R. F. , Gangnard Stephane , Srivastava Anand , Braks Joanna A. , Janse Chris J. , Gamain Benoit , Franke-Fayard Blandine , Penha-Gonçalves Carlos
Published: April 2016

Plasmodium falciparum
infection during pregnancy leads to abortions, stillbirth, low birth weight, and maternal mortality. Infected erythrocytes (IEs) accumulate in the placenta by adhering to chondroitin sulfate A (CSA) via var2CSA protein exposed on the
P. falciparum
IE membrane.
Plasmodium berghei
IE infection in pregnant BALB/c mice is a model for severe placental malaria (PM). Here, we describe a transgenic
P. berghei
parasite expressing the full-length var2CSA extracellular region (domains DBL1X to DBL6ε) fused to a
P. berghei
exported protein (EMAP1) and characterize a var2CSA-based mouse model of PM. BALB/c mice were infected at midgestation with different doses of
P. berghei-
var2CSA (
P. berghei
-VAR) or
P. berghei
wild-type IEs. Infection with 10
4
P. berghei
-VAR IEs induced a higher incidence of stillbirth and lower fetal weight than
P. berghei
. At doses of 10
5
and 10
6
IEs,
P. berghei
-VAR-infected mice showed increased maternal mortality during pregnancy and fetal loss, respectively. Parasite loads in infected placentas were similar between parasite lines despite differences in maternal outcomes. Fetal weight loss normalized for parasitemia was higher in
P. berghei
-VAR-infected mice than in
P. berghei
-infected mice.
In vitro
assays showed that higher numbers of
P. berghei
-VAR IEs than
P. berghei
IEs adhered to placental tissue. Immunization of mice with
P. berghei
-VAR elicited IgG antibodies reactive to DBL1-6 recombinant protein, indicating that the topology of immunogenic epitopes is maintained between DBL1-6–EMAP1 on
P. berghei
-VAR and recombinant DBL1-6 (recDBL1-6). Our data suggested that impairments in pregnancy caused by
P. berghei
-VAR infection were attributable to var2CSA expression. This model provides a tool for preclinical evaluation of protection against PM induced by approaches that target var2CSA.
Cellular Microbiology of Mycoplasma canis
Authors: Michaels Dina L. , Leibowitz Jeffrey A. , Azaiza Mohammed T. , Shil Pollob K. , Shama Suzanne M. , Kutish Gerald F. , Distelhorst Steven L. , Balish Mitchell F. , May Meghan A. , Brown Daniel R.
Published: April 2016

Mycoplasma canis
can infect many mammalian hosts but is best known as a commensal or opportunistic pathogen of dogs. The unexpected presence of
M. canis
in brains of dogs with idiopathic meningoencephalitis prompted new
in vitro
studies to help fill the void of basic knowledge about the organism's candidate virulence factors, the host responses that it elicits, and its potential roles in pathogenesis. Secretion of reactive oxygen species and sialidase varied quantitatively (
P
< 0.01) among strains of
M. canis
isolated from canine brain tissue or mucosal surfaces. All strains colonized the surface of canine MDCK epithelial and DH82 histiocyte cells and murine C8-D1A astrocytes. Transit through MDCK and DH82 cells was demonstrated by gentamicin protection assays and three-dimensional immunofluorescence imaging. Strains further varied (
P
< 0.01) in the extents to which they influenced the secretion of tumor necrosis factor alpha (TNF-α) and the neuroendocrine regulatory peptide endothelin-1 by DH82 cells. Inoculation with
M. canis
also decreased major histocompatibility complex class II (MHC-II) antigen expression by DH82 cells (
P
< 0.01), while secretion of gamma interferon (IFN-γ), interleukin-6 (IL-6), interleukin-10 (IL-10), and complement factor H was unaffected. The basis for differences in the responses elicited by these strains was not obvious in their genome sequences. No acute cytopathic effects on any homogeneous cell line, or consistent patterns of
M. canis
polyvalent antigen distribution in canine meningoencephalitis case brain tissues, were apparent. Thus, while it is not likely a primary neuropathogen,
M. canis
has the capacity to influence meningoencephalitis through complex interactions within the multicellular and neurochemical
in vivo
milieu.
The Tick Protein Sialostatin L2 Binds to Annexin A2 and Inhibits NLRC4-Mediated Inflammasome Activation
Authors: Wang Xiaowei , Shaw Dana K. , Sakhon Olivia S. , Snyder Greg A. , Sundberg Eric J. , Santambrogio Laura , Sutterwala Fayyaz S. , Dumler J. Stephen , Shirey Kari Ann , Perkins Darren J. , Richard Katharina , Chagas Andrezza C. , Calvo Eric , Kopecký Jan , Kotsyfakis Michail , Pedra Joao H. F.
Published: April 2016

Tick saliva contains a number of effector molecules that inhibit host immunity and facilitate pathogen transmission. How tick proteins regulate immune signaling, however, is incompletely understood. Here, we describe that loop 2 of sialostatin L2, an anti-inflammatory tick protein, binds to annexin A2 and impairs the formation of the NLRC4 inflammasome during infection with the rickettsial agent
Anaplasma phagocytophilum
. Macrophages deficient in annexin A2 secreted significantly smaller amounts of interleukin-1β (IL-1β) and IL-18 and had a defect in NLRC4 inflammasome oligomerization and caspase-1 activation. Accordingly,
Annexin a2
-deficient mice were more susceptible to
A. phagocytophilum
infection and showed splenomegaly, thrombocytopenia, and monocytopenia. Providing translational support to our findings, better binding of annexin A2 to sialostatin L2 in sera from 21 out of 23 infected patients than in sera from control individuals was also demonstrated. Overall, we establish a unique mode of inflammasome evasion by a pathogen, centered on a blood-feeding arthropod.
Proper Control of Caulobacter crescentus Cell Surface Adhesion Requires the General Protein Chaperone DnaK
Authors: Eaton Daniel S. , Crosson Sean , Fiebig Aretha
Published: April 2016

Growth in a surface-attached bacterial community, or biofilm, confers a number of advantages. However, as a biofilm matures, high-density growth imposes stresses on individual cells, and it can become less advantageous for progeny to remain in the community. Thus, bacteria employ a variety of mechanisms to control attachment to and dispersal from surfaces in response to the state of the environment. The freshwater oligotroph
Caulobacter crescentus
can elaborate a polysaccharide-rich polar organelle, known as the holdfast, which enables permanent surface attachment. Holdfast development is strongly inhibited by the small protein HfiA; mechanisms that control HfiA levels in the cell are not well understood. We have discovered a connection between the essential general protein chaperone, DnaK, and control of
C. crescentus
holdfast development.
C. crescentus
mutants partially or completely lacking the C-terminal substrate binding “lid” domain of DnaK exhibit enhanced bulk surface attachment. Partial or complete truncation of the DnaK lid domain increases the probability that any single cell will develop a holdfast by 3- to 10-fold. These results are consistent with the observation that steady-state levels of an HfiA fusion protein are significantly diminished in strains that lack the entire lid domain of DnaK. While dispensable for growth, the lid domain of
C. crescentus
DnaK is required for proper chaperone function, as evidenced by observed dysregulation of HfiA and holdfast development in strains expressing lidless DnaK mutants. We conclude that DnaK is an important molecular determinant of HfiA stability and surface adhesion control.

IMPORTANCE
Regulatory control of cell adhesion ensures that bacterial cells can transition between free-living and surface-attached states. We define a role for the essential protein chaperone, DnaK, in the control of
Caulobacter crescentus
cell adhesion.
C. crescentus
surface adhesion is mediated by an envelope-attached organelle known as the holdfast. Holdfast development is tightly controlled by HfiA, a small protein inhibitor that directly interacts with a WecG/TagA-family glycosyltransferase required for holdfast biosynthesis. We demonstrate that the C-terminal lid domain of DnaK is not essential for growth but is necessary for proper control of HfiA levels in the cell and for control of holdfast adhesin development.
Facilitated Dissociation of a Nucleoid Protein from the Bacterial Chromosome
Authors: Hadizadeh Nastaran , Johnson Reid C. , Marko John F.
Published: April 2016

Off-rates of proteins from the DNA double helix are widely considered to be dependent only on the interactions inside the initially bound protein-DNA complex and not on the concentration of nearby molecules. However, a number of recent single-DNA experiments have shown off-rates that depend on solution protein concentration, or “facilitated dissociation.” Here, we demonstrate that this effect occurs for the major
Escherichia coli
nucleoid protein Fis on isolated bacterial chromosomes. We isolated
E. coli
nucleoids and showed that dissociation of green fluorescent protein (GFP)-Fis is controlled by solution Fis concentration and exhibits an “exchange” rate constant (
k
exch
) of ≈10
4
M
−1
s
−1
, comparable to the rate observed in single-DNA experiments. We also show that this effect is strongly salt dependent. Our results establish that facilitated dissociation can be observed
in vitro
on chromosomes assembled
in vivo
.

IMPORTANCE
Bacteria are important model systems for the study of gene regulation and chromosome dynamics, both of which fundamentally depend on the kinetics of binding and unbinding of proteins to DNA. In experiments on isolated
E. coli
chromosomes, this study showed that the prolific transcription factor and chromosome packaging protein Fis displays a strong dependence of its off-rate from the bacterial chromosome on Fis concentration, similar to that observed in
in vitro
experiments. Therefore, the free cellular DNA-binding protein concentration can strongly affect lifetimes of proteins bound to the chromosome and must be taken into account in quantitative considerations of gene regulation. These results have particularly profound implications for transcription factors where DNA binding lifetimes can be a critical determinant of regulatory function.
Characterization of Clostridium difficile Spores Lacking Either SpoVAC or Dipicolinic Acid Synthetase
Authors: Donnelly M. Lauren , Fimlaid Kelly A. , Shen Aimee
Published: April 2016

The spore-forming obligate anaerobe
Clostridium difficile
is a leading cause of antibiotic-associated diarrhea around the world. In order for
C. difficile
to cause infection, its metabolically dormant spores must germinate in the gastrointestinal tract. During germination, spores degrade their protective cortex peptidoglycan layers, release dipicolinic acid (DPA), and hydrate their cores. In
C. difficile
, cortex hydrolysis is necessary for DPA release, whereas in
Bacillus subtilis
, DPA release is necessary for cortex hydrolysis. Given this difference, we tested whether DPA synthesis and/or release was required for
C. difficile
spore germination by constructing mutations in either
spoVAC
or
dpaAB
, which encode an ion channel predicted to transport DPA into the forespore and the enzyme complex predicted to synthesize DPA, respectively.
C. difficile
spoVAC
and
dpaAB
mutant spores lacked DPA but could be stably purified and were more hydrated than wild-type spores; in contrast,
B. subtilis
spoVAC
and
dpaAB
mutant spores were unstable. Although
C. difficile
spoVAC
and
dpaAB
mutant spores exhibited wild-type germination responses, they were more readily killed by wet heat. Cortex hydrolysis was not affected by this treatment, indicating that wet heat inhibits a stage downstream of this event. Interestingly,
C. difficile
spoVAC
mutant spores were significantly more sensitive to heat treatment than
dpaAB
mutant spores, indicating that SpoVAC plays additional roles in conferring heat resistance. Taken together, our results demonstrate that SpoVAC and DPA synthetase control
C. difficile
spore resistance and reveal differential requirements for these proteins among the
Firmicutes
.

IMPORTANCE
Clostridium difficile
is a spore-forming obligate anaerobe that causes ∼500,000 infections per year in the United States. Although spore germination is essential for
C. difficile
to cause disease, the factors required for this process have been only partially characterized. This study describes the roles of two factors, DpaAB and SpoVAC, which control the synthesis and release of dipicolinic acid (DPA), respectively, from bacterial spores. Previous studies of these proteins in other spore-forming organisms indicated that they are differentially required for spore formation, germination, and resistance. We now show that the proteins are dispensable for
C. difficile
spore formation and germination but are necessary for heat resistance. Thus, our study further highlights the diverse functions of DpaAB and SpoVAC in spore-forming organisms.