bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigallocatechin gallate hinders human hepatoma and colon cancer sphere formation
Authors: Wubetu Gizachew Y , Shimada Mitsuo , Morine Yuji , Ikemoto Tetsuya , Ishikawa Daichi , Iwahashi Shuichi , Yamada Shinichiro , Saito Yu , Arakawa Yusuke , Imura Satoru
Published: August 2015

Background and Aim

The long‐term survival of patients with hepatocellular carcinoma remains unsatisfactory because of the presence of cancer stem cells (CSCs), which are responsible for tumor recurrence and chemoresistance after hepatectomy. Drugs that selectively target CSCs thus offer great promise for cancer treatment. Although the antitumor effects of epigallocatechin gallate (EGCG) have been reported in some cancer cells, its effects on CSCs remain poorly studied. In this study, we investigated the effects of EGCG on human hepatoma and colon CSCs.

Methods

HepG2 and HCT‐116 cell lines were enriched by sphere formation, and their gene‐expression profiles were analyzed by quantitative real‐time polymerase chain reaction. EGCG‐induced growth inhibition in the parental cells was determined by WST‐8 assay, and protein expression was assessed by western blotting. Cell cycle profile and apoptosis analysis was performed using flow cytometer.

Results

Sphere‐derived cells grown in serum‐free, nonadherent cultures showed increased expression of stem cell markers, Nek2, and ATP‐binding cassette transporter genes, compared with parental cells grown in conventional culture. EGCG induced growth inhibition in the parental cells in a dose‐dependent manner. EGCG also inhibited self‐renewal in hepatoma and colon CSCs, attenuated the expression of stem cell markers and ATP‐binding cassette transporter genes, which are putative molecules associated with treatment resistance in CSCs, and decreased the transcription of Nek2 and p‐Akt, resulting in the inhibition of Akt signaling. EGCG also altered cell cycle profile and apoptosis, which may in part play an important role in EGCG‐induced cancer cell death.

Conclusions

Overall, these results suggest that EGCG could be a useful chemopreventive agent for targeting hepatocellular carcinoma and colon CSCs, in combination with standard chemotherapies.
Introducing Law Students to Public Health Law through a Bed Bug Scenario
Authors: Bard Jennifer S.
Published: August 2015

Bedbugs are tiny, wingless insects which feed on mammal blood and leave behind painful, itchy sores. Although they can live in other settings, they are most commonly found in warm, dark places inhabited by humans, like beds. After being absent in the United States for over 60 years, thanks to powerful pesticides, bed bugs (Cimex lectularius), have returned in force and are present in every state and nearly every city. For reasons not entirely understood, bed bugs have developed resistance to traditional pesticides such as Permethrin and are therefore difficult to control. Although commonly believed to be associated with dirty housekeeping and associated with substandard housing, bed bugs are equally likely to be present in five-star hotels as they are in homeless shelters.
Improving Regulatory Enforcement in the Face of Inadequate Resources
Authors: Hoffman Sharona
Published: August 2015

In law school we often focus on the importance of carefully crafting statutory and regulatory language. Textual ambiguities or sloppiness can significantly impair the efficacy of laws and regulations. Just as important as meticulous drafting, however, is the government’s ability to enforce its rules. In the absence of adequate enforcement resources, the government’s regulatory initiatives may well fail. The ability to promote public welfare depends as much on regulatory compliance as it does on the text of the regulations themselves.
Disaster Relief: Restricting and Regulating Public Health Interventions
Authors: Lewis Browne
Published: August 2015

The information contained in this teaching module and the accompanying PowerPoint slides is appropriate for use in a survey public health law course or seminar. The purpose of this lesson is two-fold. The first objective is to provide law students with an overview of the authority public health agencies have to set and enforce policies necessary to keep the population healthy. The second objective is to inform law students about the legal constraints courts have placed upon the actions of those agencies. The module ends with a project designed to give law students the opportunity to apply the law to a “real world” situation.
Sleep, health and memory: comparing parents of typically developing children and parents of children with special health‐care needs
Authors: Mcbean Amanda L. , Schlosnagle Leo
Published: August 2015

Parents of children with special healthcare needs (CSHCNs) report poorer sleep than parents of typically developing (TD) children, which has been associated with poorer mental health. The relations between sleep disturbances and general health and memory among this population are unknown. The current study aimed to replicate the findings that parents of CSHCNs report poorer sleep quality than parents of TD children, and further examine how sleep is related to general health and memory. Participants (75 parents of TD children; 97 parents of CSHCNs) completed an online questionnaire consisting of: demographics, the Pittsburgh Sleep Quality Index (PSQI), the Prospective Retrospective Memory Questionnaire (PRMQ) and the Healthy Days Measure. Parents of CSHCNs reported worse global sleep than parents of TD children. Parents of CSHCNs took longer to fall asleep at night, had shorter sleep duration and worse subjective sleep quality than parents of TD children. Parents of CSHCNs also had worse prospective memory and were more likely to report poor general health than parents of TD children. Poorer sleep quality was associated with worse memory and health among both parents of TD children and parents of CSHCNs. Results from this study highlight the importance of addressing the sleep of parents of CSHCNs and support the need for more research in this area. By recognizing factors associated with parent's health and functioning, service providers may be better able to implement support programs for parents of CSHCNs.
The formation conditions of enstatite chondrites: Insights from trace element geochemistry of olivine‐bearing chondrules in Sahara 97096 (EH3)
Authors: Jacquet Emmanuel , Alard Olivier , Gounelle Matthieu
Published: August 2015

We report in situ LA‐ICP‐MS trace element analyses of silicate phases in olivine‐bearing chondrules in the Sahara 97096 (EH3) enstatite chondrite. Most olivine and enstatite present rare earth element (REE) patterns comparable to their counterparts in type I chondrules in ordinary chondrites. They thus likely share a similar igneous origin, likely under similar redox conditions. The mesostasis however frequently shows negative Eu and/or Yb (and more rarely Sm) anomalies, evidently out of equilibrium with olivine and enstatite. We suggest that this reflects crystallization of oldhamite during a sulfidation event, already inferred by others, during which the mesostasis was molten, where the complementary positive Eu and Yb anomalies exhibited by oldhamite would have possibly arisen due to a divalent state of these elements. Much of this igneous oldhamite would have been expelled from the chondrules, presumably by inertial acceleration or surface tension effects, and would have contributed to the high abundance of opaque nodules found outside them in EH chondrites. In two chondrules, olivine and enstatite exhibit negatively sloped REE patterns, which may be an extreme manifestation of a general phenomenon (possibly linked to near‐liquidus partitioning) underlying the overabundance of light REE observed in most chondrule silicates relative to equilibrium predictions. The silicate phases in one of these two chondrules show complementary Eu, Yb, and Sm anomalies providing direct evidence for the postulated occurrence of the divalent state for these elements at some stage in the formation reservoir of enstatite chondrites. Our work supports the idea that the peculiarities of enstatite chondrites may not require a condensation sequence at high C/O ratios as has long been believed.
Fe‐Mg interdiffusion profiles in rimmed forsterite grains in the Allende matrix: Time–temperature constraints for the parent body metamorphism
Authors: Cuvillier Priscille , Leroux Hugues , Jacob Damien , Hirel Pierre
Published: August 2015

The Allende matrix is dominated by micron‐sized lath‐shaped fayalitic olivine grains with a narrow compositional range (Fa40–50). Fayalitic olivines also occur as rims around forsterite grains in chondrules and isolated forsterite fragments in the matrix or as veins cross‐cutting the grains. Allende is a type 3 CV carbonaceous chondrite having experienced a moderate thermal metamorphism. There is therefore a strong chemical disequilibrium between the large forsterite grains and the fayalite‐rich fine‐grained matrix. Chemical gradients at interfaces are poorly developed and thus not accessible using conventional techniques. Here, we used analytical transmission electron microscopy to study the microstructure of the fayalite‐rich matrix grains and interfaces with forsterite fragments. We confirm that fayalitic grains in the matrix and fayalitic rims around forsterite fragments have the same properties, suggesting a common origin after the accretion of the parent body of Allende. Composition profiles at the rim/forsterite interfaces exhibit a plateau in the rim (typically Fa45), a compositional jump of 10 Fa% at the interface, and a concentration gradient in the forsterite grain. Whatever the studied forsterite grain or whatever the nature of the interface, the Fe‐Mg profiles in forsterite grains have the same length of about 1.5 μm. This strongly suggests that the composition profiles were formed by solid‐state diffusion during the thermal metamorphism episode. Time–temperature couples associated with the diffusion process during thermal metamorphism are deduced from profile modeling. Considering the uncertainties on the diffusion coefficient value, we found that the peak temperature in Allende is ranging from 425 to 505 °C.
Analytical Model for Viscous Wall Dampers
Authors: Hejazi F. , Shoaei M. Dalili , Tousi A. , Jaafar M. S.
Published: August 2015

By now, many civil engineering researchers have extensively studied the application of earthquake energy dissipation systems in seismic‐resistant buildings. Earthquake energy dissipation systems play an important role in enhancing the sustainability of structures against seismic excitation. Frame buildings are strengthened by installing damper devices as supplemental structural members. This article presents the finite‐element‐based development of an analytical model for a viscous wall damper (VWD) device, an alternative to other earthquake energy dissipation systems, which can diminish the effect of earthquakes on structures and improve the seismic performance of multistory buildings subjected to ground motion. The constitutive law of VWDs has been formulated and integrated to develop a finite element model of VWD compatible with the reinforced concrete (RC) structure analytical model. Then, the finite element algorithm has been developed for inelastic analysis of RC buildings equipped with VWD devices capable of detecting damage to both structural members and damper connections under dynamic loading. Based on the developed system, the special finite element program was codified and verified by applying it to a real model of a RC building with supplementary VWD devices. Influence of VWDs on seismic performance of the RC building during earthquake excitation was evaluated. The proposed analytical model for VWD is verified by using experimental test data and analysis result proved that this energy dissipation system succeeds by substantially diminishing and dissipating a structure's induced seismic responses. Also the parametric study indicated that the damping coefficient is very effective on performance of VWD.
Friend or foe? The effects of managerial politics on NPD team communication, collaboration and project success
Authors: Kyriazis Elias , Massey Graham , Couchman Paul , Johnson Lester
Published: August 2015

Much existing work on new product development (NPD) team integration takes an economically rational perspective, specifying appropriate systems, structures and interactions. Few studies however have explored the effects of politics on working relationships between technically trained managers (TTMs; e.g., research and development managers) and marketing managers (MMs) during NPD. Our results reveal that intra‐team politics has positive and negative effects on TTM/MM communication. This is important because communication positively influences collaboration and NPD success. Moreover, the effects of communication variables on these two outcome variables differ depending on whether one is a TTM or MM.
WRKY40 and WRKY6 act downstream of the green leaf volatile E‐2‐hexenal in Arabidopsis
Authors: Mirabella Rossana , Rauwerda Han , Allmann Silke , Scala Alessandra , Spyropoulou Eleni A. , de Vries Michel , Boersma Maaike R. , Breit Timo M. , Haring Michel A. , Schuurink Robert C.
Published: August 2015

Plants are known to be responsive to volatiles, but knowledge about the molecular players involved in transducing their perception remains scarce. We study the response of Arabidopsis thaliana to E‐2‐hexenal, one of the green leaf volatiles (GLV) that is produced upon wounding, herbivory or infection with pathogens. We have taken a transcriptomics approach to identify genes that are induced by E‐2‐hexenal, but not by defence hormones or other GLVs. Furthermore, by studying the promoters of early E‐2‐hexenal‐induced genes we determined that the only statistically enriched cis‐element was the W‐box motif. Since members of the plant‐specific family of WRKY transcription factors act in trans on this cis‐element, we focused on WRKY6, 40 and 53 that were most strongly induced by E‐2‐hexenal. Root elongation of Arabidopsis seedlings of the wrky40 wrky6 double mutant was much less inhibited than in wt plants, similar to the E‐2‐hexenal‐responsive mutant her1, which is perturbed in γ‐amino butyric acid (GABA) metabolism. The induction of several of the E‐2‐hexenal‐specific genes was much higher in the wrky40, wrky6 or wrky40 wrky6 mutants, including GAD4, a glutamate decarboxylase that catalyzes the formation of GABA from glutamate. In conclusion, WRKY6 and 40 seem to act as important players transducing E‐2‐hexenal perception.
The Effectiveness of Clinically Indicated Replacement of Peripheral Intravenous Catheters: An Evidence Review With Implications for Clinical Practice
Authors: Morrison Kimberly , Holt Karyn E.
Published: August 2015

Background

Current clinical guidelines from the Centers for Disease Control and Prevention (CDC; 2011) state that peripheral intravenous catheters are to be replaced every 72–96 hr to prevent infection and phlebitis in the adult patient. It is unclear whether this practice reduces the incidence of phlebitis or other infections.

Aim

The aim of this study was to examine levels I and II evidence to determine if replacing peripheral intravenous catheters only when clinically indicated compared to every 72–96 hr increases the adult patient's risk for infection or phlebitis.

Methods

The following patient or population, intervention, comparison, outcome question was used to search the literature databases PubMed, ClinicalKey, ProQuest, Ovid SP, and CINAHL: In the adult patient requiring a peripheral vascular catheter (P), does replacing the catheter only when clinically indicated (I) compared to replacing the catheter every 72–96 hr (C) increase the occurrence of phlebitis and infection (O)? A set of specific search criteria along with critical appraisal tools was used to identify relative studies.

Results

Four level II randomized controlled trials with no less than 155 subjects, and two level I meta‐analyses reviewing a total of 13 research studies indicated that the replacement of peripheral intravenous catheters only when clinically indicated does not increase patient risk of phlebitis or infection when compared to the current practice of routine replacement between 72 and 96 hr in the adult patient population.

Linking Evidence to Action

The current practice of replacing peripheral intravenous catheters every 72–96 hr does not decrease the incidence of phlebitis or infection when compared to replacing catheters when clinically indicated in the adult population. By translating this research into current practice, healthcare costs and nursing care time will decrease, and unnecessary invasive procedures would be eliminated thereby increasing patient safety and satisfaction.
A Preliminary Design Tradeoff Study for an Advanced Propulsion Technology Rotorcraft at Mission Level
Authors: Ali Fakhre , Goulos Ioannis , Pachidis Vassilios
Published: August 2015

This paper aims to present an integrated rotorcraft (RC) multidisciplinary simulation framework, deployed for the comprehensive assessment of combined RC–powerplant systems at mission level. The proposed methodology comprises a wide-range of individual modeling theories applicable to RC performance and flight dynamics, as well as the gas turbine engine performance. The overall methodology has been deployed to conduct a preliminary tradeoff study for a reference simple cycle (SC) and conceptual regenerative twin-engine-light (TEL) and twin-engine-medium (TEM) RC configurations, modeled after the Airbus Helicopters Bo105 and Aérospatiale SA330 models, simulated under the representative mission scenarios. The installed engines corresponding to both reference RC are notionally modified by incorporating a heat exchanger (HE), enabling heat transfer between the exhaust gas and the compressor delivery air to the combustion chamber. This process of preheating the compressor delivery air prior to combustion chamber leads to a lower fuel input requirements compared to the reference SC engine. The benefits arising from the adoption of the on-board HE are first presented by conducting part-load performance analysis against the reference SC engine. The acquired results suggest substantial reduction in specific fuel consumption (SFC) for a major part of the operating power range with respect to both RC configurations. The study is further extended to quantify mission fuel burn (MFB) saving limit by conducting an extensive HE tradeoff analyses at mission level. The optimum fuel burn saving limit resulting from the incorporation of on-board HEs is identified within realistically defined missions, corresponding to modern RC operations. The acquired results from the mission analyses tradeoff study suggest that the suboptimum regenerated RC configurations are capable of achieving significant reduction in MFB, while simultaneously maintaining the respective airworthiness requirements in terms of one-engine-inoperative. The proposed methodology can effectively be regarded as an enabling technology for the comprehensive assessment of conventional and conceptual RC–powerplant systems at mission level.
Optical and Thermal Analysis of a Pressurized-Air Receiver Cluster for a 50 MWe Solar Power Tower
Authors: Hischier I. , Poživil P. , Steinfeld A.
Published: August 2015

The optical design and thermal performance of a solar power tower system using an array of high-temperature pressurized air-based solar receivers is analyzed for Brayton, recuperated, and combined Brayton–Rankine cycles. A 50 MWe power tower system comprising a cluster of 500 solar receiver modules, each attached to a hexagon-shaped secondary concentrator and arranged side-by-side in a honeycomb-type structure following a spherical fly-eye optical configuration, can yield a peak solar-to-electricity efficiency of 37%.
Analytical and Experimental Investigation to Determine the Variation of Hottel–Whillier–Bliss Constants for a Scaled Forced Circulation Flat-Plate Solar Water Heater
Authors: Arunachala U. C. , Siddhartha Bhatt M. , Sreepathi L. K.
Published: August 2015

Fixed tilt flat-plate solar thermal collectors, popularly known as solar water heaters, still remain as one of the most interesting technologies for utilization of solar energy. The system performance deteriorates due to scaling because of the continuous use of hard water as feed water. The present study deals with the experimental and analytical approach to determine the variation of Hottel–Whillier–Bliss (H–W–B) constants (which compactly represent the efficiency characteristics of a solar water heater) due to variation in solar power input and degree of scaling in case of forced circulation system (FCS) without considering the variation of input power to the circulating pump. Indoor tests are performed with a copper tube to investigate the flow characteristics. This forms a part of conventional FCS, in place of the usual nine-fin tube array in a full-fledged collector. In indoor tests, electrical heating is favored to simulate solar radiation level. Various energy parameters are determined and compared by incorporating the developed numerical code FLATSCALE. Variation between experimental and analytical mass flow rate, overall heat loss coefficient, and H–W–B constants with simulated solar radiation level is plotted. In scaled condition, the drop in instantaneous efficiency is due to both scale thickness and reduced water flow rate. Scale thickness acts as an additional thermal conductive resistance between absorber plate and flowing water. Overall heat loss coefficient increases as absorber plate temperature is high during reduced flow rate. The maximum deviation observed is 21.68% in mass flow rate, 14.64% in absorber plate mean temperature, 7.86% in overall heat loss coefficient, and 12.04% in instantaneous efficiency. Compared to a clean tube, a highly scaled tube of 3.7 mm scale thickness indicates a drop of 4.76% in instantaneous efficiency and 40.28% in mass flow rate. It is concluded that the growth of scale in FCS does not affect the instantaneous efficiency significantly because of the margin in heat carrying capacity of water in spite of high drop in the flow rate.
Thermal Repair of Incomplete Back Contact Insulation (P1) in Cu(In,Ga)Se2 Photovoltaic Thin-Film Modules
Authors: Misic B. , Pieters B. E. , Rau U.
Published: August 2015

We investigate the repair of interruptions in the back contact (P1) scribing line between two Mo back electrodes by thermally induced fractures. The fractures occur during Cu(In,Ga)Se2 (CIGS) absorber co-evaporation, as it is applied in CIGS thin-film module manufacturing and can effectively repair line interruptions of up to about 70 μm. Additionally, we present that a thermal treatment after P1 laser scribing and before CIGS co-evaporation can repair even interruptions of up to 1 mm. The fractures which are required for insulation are only of approximately 4 μm width which indicates the potential for further reduction of the interconnection width in CIGS modules and therefore improvement of the electrical module efficiency.
GABA, the time keeper
Authors: Prabakaran Sudhakaran
Published: August 2015

Differences in intracellular chloride concentration of neurons in suprachiasmatic nuclei and neurotransmitter GABA encode seasonal day-night variations.
S-nitrosylation links obesity and cell stress
Authors: Ray L. Bryan
Published: August 2015

Altered S-nitrosylation of a key protein involved in the unfolded protein response interferes with proteostasis in obesity.
How plant parasites evolved to find hosts
Authors: Zahn Laura M.
Published: August 2015

Obligate parasitic Orobanchaceae plants germinate after sensing strigolactones exuded from host roots.
How Robust Are Malaria Parasite Clearance Rates as Indicators of Drug Effectiveness and Resistance?
Authors: Hastings Ian M. , Kay Katherine , Hodel Eva Maria
Published: August 2015

Artemisinin-based combination therapies (ACTs) are currently the first-line drugs for treating uncomplicated falciparum malaria, the most deadly of the human malarias. Malaria parasite clearance rates estimated from patients' blood following ACT treatment have been widely adopted as a measure of drug effectiveness and as surveillance tools for detecting the presence of potential artemisinin resistance. This metric has not been investigated in detail, nor have its properties or potential shortcomings been identified. Herein, the pharmacology of drug treatment, parasite biology, and human immunity are combined to investigate the dynamics of parasite clearance following ACT. This approach parsimoniously recovers the principal clinical features and dynamics of clearance. Human immunity is the primary determinant of clearance rates, unless or until artemisinin killing has fallen to near-ineffective levels. Clearance rates are therefore highly insensitive metrics for surveillance that may lead to overconfidence, as even quite substantial reductions in drug sensitivity may not be detected as lower clearance rates. Equally serious is the use of clearance rates to quantify the impact of ACT regimen changes, as this strategy will plausibly miss even very substantial increases in drug effectiveness. In particular, the malaria community may be missing the opportunity to dramatically increase ACT effectiveness through regimen changes, particularly through a switch to twice-daily regimens and/or increases in artemisinin dosing levels. The malaria community therefore appears overreliant on a single metric of drug effectiveness, the parasite clearance rate, that has significant and serious shortcomings.
Altering Antimalarial Drug Regimens May Dramatically Enhance and Restore Drug Effectiveness
Authors: Kay Katherine , Hodel Eva Maria , Hastings Ian M.
Published: August 2015

There is considerable concern that malaria parasites are starting to evolve resistance to the current generation of antimalarial drugs, the artemisinin-based combination therapies (ACTs). We use pharmacological modeling to investigate changes in ACT effectiveness likely to occur if current regimens are extended from 3 to 5 days or, alternatively, given twice daily over 3 days. We show that the pharmacology of artemisinins allows both regimen changes to substantially increase the artemisinin killing rate. Malaria patients rarely contain more than 10
12
parasites, while the standard dosing regimens allow approximately 1 in 10
10
parasites to survive artemisinin treatment. Parasite survival falls dramatically, to around 1 in 10
17
parasites if the dose is extended or split; theoretically, this increase in drug killing appears to be more than sufficient to restore failing ACT efficacy. One of the most widely used dosing regimens, artemether-lumefantrine, already successfully employs a twice-daily dosing regimen, and we argue that twice-daily dosing should be incorporated into all ACT regimen design considerations as a simple and effective way of ensuring the continued long-term effectiveness of ACTs.
Evaluation of Gallium Citrate Formulations against a Multidrug-Resistant Strain of Klebsiella pneumoniae in a Murine Wound Model of Infection
Authors: Thompson Mitchell G. , Truong-Le Vu , Alamneh Yonas A. , Black Chad C. , Anderl Jeff , Honnold Cary L. , Pavlicek Rebecca L. , Abu-Taleb Rania , Wise Matthew C. , Hall Eric R. , Wagar Eric J. , Patzer Eric , Zurawski Daniel V.
Published: August 2015

Skin and soft tissue infections (SSTIs) are a common occurrence in health care facilities with a heightened risk for immunocompromised patients.
Klebsiella pneumoniae
has been increasingly implicated as the bacterial agent responsible for SSTIs, and treatment can be challenging as more strains become multidrug resistant (MDR). Therefore, new treatments are needed to counter this bacterial pathogen. Gallium complexes exhibit antimicrobial activity and are currently being evaluated as potential treatment for bacterial infections. In this study, we tested a topical formulation containing gallium citrate (GaCi) for the treatment of wounds infected with
K. pneumoniae
. First, the MIC against
K. pneumoniae
ranged from 0.125 to 2.0 μg/ml GaCi. After this
in vitro
efficacy was established, two topical formulations with GaCi (0.1% [wt/vol] and 0.3% [wt/vol]) were tested in a murine wound model of MDR
K. pneumoniae
infection. Gross pathology and histopathology revealed
K. pneumoniae
-infected wounds appeared to close faster with GaCi treatment and were accompanied by reduced inflammation compared to those of untreated controls. Similarly, quantitative indications of infection remediation, such as reduced weight loss and wound area, suggested that treatment improved outcomes compared to those of untreated controls. Bacterial burdens were measured 1 and 3 days following inoculation, and a 0.5 to 1.5 log reduction of CFU was observed. Lastly, upon scanning electron microscopy analysis, GaCi treatment appeared to prevent biofilm formation on dressings compared to those of untreated controls. These results suggest that with more preclinical testing, a topical application of GaCi may be a promising alternative treatment strategy for
K. pneumoniae
SSTI.
N
-Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans
Authors: Lackner Michaela , Binder Ulrike , Reindl Martin , Gönül Beyhan , Fankhauser Hannes , Mair Christian , Nagl Markus
Published: August 2015

N
-Chlorotaurine (NCT), a well-tolerated endogenous long-lived oxidant that can be applied topically as an antiseptic, was tested on its fungicidal activity against
Scedosporium
and
Lomentospora
, opportunistic fungi that cause severe infections with limited treatment options, mainly in immunocompromised patients. In quantitative killing assays, both hyphae and conidia of
Scedosporium apiospermum
,
Scedosporium boydii
, and
Lomentospora prolificans
(formerly
Scedosporium prolificans
) were killed by 55 mM (1.0%) NCT at pH 7.1 and 37°C, with a 1- to 4-log
10
reduction in CFU after 4 h and a 4- to >6-log
10
reduction after 24 h. The addition of ammonium chloride to NCT markedly increased this activity. LIVE/DEAD staining of conidia treated with 1.0% NCT for 0.5 to 3 h increased the permeability of the cell wall and membrane. Preincubation of the test fungi in 1.0% NCT for 10 to 60 min delayed the time to germination of conidia by 2 h to >12 h and reduced their germination rate by 10.0 to 100.0%. Larvae of
Galleria mellonella
infected with 1.0 × 10
7
conidia of
S. apiospermum
and
S. boydii
died at a rate of 90.0 to 100% after 8 to 12 days. The mortality rate was reduced to 20 to 50.0% if conidia were preincubated in 1.0% NCT for 0.5 h or if heat-inactivated conidia were used. Our study demonstrates the fungicidal activity of NCT against different
Scedosporium
and
Lomentospora
species. A postantifungal effect connected with a loss of virulence occurs after sublethal incubation times. The augmenting effect of ammonium chloride can be explained by the formation of monochloramine.
Use of a Combination Biomarker Algorithm To Identify Medical Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection
Authors: Han Jennifer H. , Nachamkin Irving , Coffin Susan E. , Gerber Jeffrey S. , Fuchs Barry , Garrigan Charles , Han Xiaoyan , Bilker Warren B. , Wise Jacqueleen , Tolomeo Pam , Lautenbach Ebbing ,   for the Prevention Epicenters Program of the Centers for Disease ControlPrevention
Published: August 2015

Sepsis remains a diagnostic challenge in the intensive care unit (ICU), and the use of biomarkers may help in differentiating bacterial sepsis from other causes of systemic inflammatory syndrome (SIRS). The goal of this study was to assess test characteristics of a number of biomarkers for identifying ICU patients with a very low likelihood of bacterial sepsis. A prospective cohort study was conducted in a medical ICU of a university hospital. Immunocompetent patients with presumed bacterial sepsis were consecutively enrolled from January 2012 to May 2013. Concentrations of nine biomarkers (α-2 macroglobulin, C-reactive protein [CRP], ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator) were determined at baseline and at 24 h, 48 h, and 72 h after enrollment. Performance characteristics were calculated for various combinations of biomarkers for discrimination of bacterial sepsis from other causes of SIRS. Seventy patients were included during the study period; 31 (44%) had bacterial sepsis, and 39 (56%) had other causes of SIRS. PCT and CRP values were significantly higher at all measured time points in patients with bacterial sepsis. A number of combinations of PCT and CRP, using various cutoff values and measurement time points, demonstrated high negative predictive values (81.1% to 85.7%) and specificities (63.2% to 79.5%) for diagnosing bacterial sepsis. Combinations of PCT and CRP demonstrated a high ability to discriminate bacterial sepsis from other causes of SIRS in medical ICU patients. Future studies should focus on the use of these algorithms to improve antibiotic use in the ICU setting.
Purification Methodology for Viable and Infective Plasmodium vivax Gametocytes That Is Compatible with Transmission-Blocking Assays
Authors: Vera Omaira , Brelas de Brito Paula , Albrecht Letusa , Martins-Campos Keillen Monick , Pimenta Paulo F. P. , Monteiro Wuelton M. , Lacerda Marcus V. G. , Lopes Stefanie C. P. , Costa Fabio T. M.
Published: August 2015

Significant progress toward the control of malaria has been achieved, especially regarding
Plasmodium falciparum
infections. However, the unique biology of
Plasmodium vivax
hampers current control strategies. The early appearance of
P. vivax
gametocytes in the peripheral blood and the impossibility of culturing this parasite are major drawbacks. Using blood samples from 40
P. vivax
-infected patients, we describe here a methodology to purify viable gametocytes and further infect anophelines. This method opens new avenues to validate transmission-blocking strategies.
Pharmacokinetic Modeling of Lamivudine and Zidovudine Triphosphates Predicts Differential Pharmacokinetics in Seminal Mononuclear Cells and Peripheral Blood Mononuclear Cells
Authors: Dumond Julie B. , Yang Kuo H. , Kendrick Racheal , Reddy Y. Sunila , Kashuba Angela D. M. , Troiani Luigi , Bridges Arlene S. , Fiscus Susan A. , Forrest Alan , Cohen Myron S.
Published: August 2015

The male genital tract is a potential site of viral persistence. Therefore, adequate concentrations of antiretrovirals are required to eliminate HIV replication in the genital tract. Despite higher zidovudine (ZDV) and lamivudine (3TC) concentrations in seminal plasma (SP) than in blood plasma (BP) (SP/BP drug concentration ratios of 2.3 and 6.7, respectively), we have previously reported lower relative intracellular concentrations of their active metabolites, zidovudine triphosphate (ZDV-TP) and lamivudine triphosphate (3TC-TP), in seminal mononuclear cells (SMCs) than in peripheral blood mononuclear cells (PBMCs) (SMC/PBMC drug concentration ratios of 0.36 and 1.0, respectively). Here, we use population pharmacokinetic (PK) modeling-based methods to simultaneously describe parent and intracellular metabolite PK in blood, semen, and PBMCs and SMCs. From this model, the time to steady state in each matrix was estimated, and the results indicate that the PK of 3TC-TP and ZDV-TP in PBMCs are different from the PK of the two in SMCs and different for the two triphosphates. We found that steady-state conditions in PBMCs were achieved within 2 days for ZDV-TP and 3 days for 3TC-TP. However, steady-state conditions in SMCs were achieved within 2 days for ZDV-TP and 2 weeks for 3TC-TP. Despite this, or perhaps because of it, ZDV-TP in SMCs does not achieve the surrogate 50% inhibitory concentration (IC
50
) (as established for PBMCs, assuming SMC IC
50
= PBMC IC
50
) at the standard 300-mg twice-daily dosing. Mechanistic studies are needed to understand these differences and to explore intracellular metabolite behavior in SMCs for other nucleoside analogues used in HIV prevention, treatment, and cure.
Potent
In Vitro
Antiproliferative Synergism of Combinations of Ergosterol Biosynthesis Inhibitors against Leishmania amazonensis
Authors: de Macedo-Silva S. T. , Visbal G. , Urbina J. A. , de Souza W. , Rodrigues J. C. F.
Published: August 2015

Leishmaniases comprise a spectrum of diseases caused by protozoan parasites of the
Leishmania
genus. Treatments available have limited safety and efficacy, high costs, and difficult administration. Thus, there is an urgent need for safer and more-effective therapies. Most trypanosomatids have an essential requirement for ergosterol and other 24-alkyl sterols, which are absent in mammalian cells. In previous studies, we showed that
Leishmania amazonensis
is highly susceptible to aryl-quinuclidines, such as E5700, which inhibit squalene synthase, and to the azoles itraconazole (ITZ) and posaconazole (POSA), which inhibit C-14α-demethylase. Herein, we investigated the antiproliferative, ultrastructural, and biochemical effects of combinations of E5700 with ITZ and POSA against
L. amazonensis
. Potent synergistic antiproliferative effects were observed against promastigotes, with fractional inhibitory concentration (FIC) ratios of 0.0525 and 0.0162 for combinations of E5700 plus ITZ and of E5700 plus POSA, respectively. Against intracellular amastigotes, FIC values were 0.175 and 0.1125 for combinations of E5700 plus ITZ and E5700 plus POSA, respectively. Marked alterations of the ultrastructure of promastigotes treated with the combinations were observed, in particular mitochondrial swelling, which was consistent with a reduction of the mitochondrial transmembrane potential, and an increase in the production of reactive oxygen species. We also observed the presence of vacuoles similar to autophagosomes in close association with mitochondria and an increase in the number of lipid bodies. Both growth arrest and ultrastructural/biochemical alterations were strictly associated with the depletion of the 14-desmethyl endogenous sterol pool. These results suggest the possibility of a novel combination therapy for the treatment of leishmaniasis.
In Vitro
Activities of Eight Antifungal Drugs against a Global Collection of Genotyped Exserohilum Isolates
Authors: Chowdhary Anuradha , Hagen Ferry , Curfs-Breuker Ilse , Madrid Hugo , de Hoog G. Sybren , Meis Jacques F.
Published: August 2015

The
in vitro
susceptibilities of 24 worldwide
Exserohilum
isolates belonging to 10 species from human and environmental sources were determined for eight antifungal drugs. The strains were characterized by internal transcribed spacer (ITS) sequencing and amplified fragment length polymorphism fingerprinting. Posaconazole had the lowest geometric mean MIC (0.16 μg/ml), followed by micafungin (0.21 μg/ml), amphotericin B (0.24 μg/ml), itraconazole (0.33 μg/ml), voriconazole (0.8 μg/ml), caspofungin (1.05 μg/ml), isavuconazole (1.38 μg/ml), and fluconazole (15.6 μg/ml).
Copper(II)-Bis(Thiosemicarbazonato) Complexes as Antibacterial Agents: Insights into Their Mode of Action and Potential as Therapeutics
Authors: Djoko Karrera Y. , Goytia Maira M. , Donnelly Paul S. , Schembri Mark A. , Shafer William M. , McEwan Alastair G.
Published: August 2015

There is increasing interest in the use of lipophilic copper (Cu)-containing complexes to combat bacterial infections. In this work, we showed that Cu complexes with bis(thiosemicarbazone) ligands [Cu(btsc)] exert antibacterial activity against a range of medically significant pathogens. Previous work using
Neisseria gonorrhoeae
showed that Cu(btsc) complexes may act as inhibitors of respiratory dehydrogenases in the electron transport chain. We now show that these complexes are also toxic against pathogens that lack a respiratory chain. Respiration in
Escherichia coli
was slightly affected by Cu(btsc) complexes, but our results indicate that, in this model bacterium, the complexes act primarily as agents that deliver toxic Cu ions efficiently into the cytoplasm. Although the chemistry of Cu(btsc) complexes may dictate their mechanism of action, their efficacy depends heavily on bacterial physiology. This is linked to the ability of the target bacterium to tolerate Cu and, additionally, the susceptibility of the respiratory chain to direct inhibition by Cu(btsc) complexes. The physiology of
N. gonorrhoeae
, including multidrug-resistant strains, makes it highly susceptible to damage by Cu ions and Cu(btsc) complexes, highlighting the potential of Cu(btsc) complexes (and Cu-based therapeutics) as a promising treatment against this important bacterial pathogen.
Biopharmaceutical Characterization of Nebulized Antimicrobial Agents in Rats: 3. Tobramycin
Authors: Marchand Sandrine , Grégoire Nicolas , Brillault Julien , Lamarche Isabelle , Gobin Patrice , Couet William
Published: August 2015

The aim of this study was to determine the biopharmaceutical characteristics of tobramycin (TOB) after nebulization in rats. TOB was administered by intravenous (i.v.) bolus or intratracheal nebulization (3 mg · kg
−1
), and concentrations were determined in plasma and epithelial lining fluid (ELF) by liquid chromatography-tandem mass spectrometry. The ratio of the TOB concentration in ELF to the plasma area under the curve (AUC) was more than 200 times as high after NEB as after i.v. bolus administration, indicating that TOB nebulization offers a biopharmaceutical advantage over i.v. administration.
Effects of Iron Chelators on the Formation and Development of Aspergillus fumigatus Biofilm
Authors: Nazik Hasan , Penner John C. , Ferreira Jose A. , Haagensen Janus A. J. , Cohen Kevin , Spormann Alfred M. , Martinez Marife , Chen Vicky , Hsu Joe L. , Clemons Karl V. , Stevens David A.
Published: August 2015

Iron acquisition is crucial for the growth of
Aspergillus fumigatus
.
A. fumigatus
biofilm formation occurs
in vitro
and
in vivo
and is associated with physiological changes. In this study, we assessed the effects of Fe chelators on biofilm formation and development. Deferiprone (DFP), deferasirox (DFS), and deferoxamine (DFM) were tested for MIC against a reference isolate via a broth macrodilution method. The metabolic effects (assessed by XTT [2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide inner salt]) on biofilm formation by conidia were studied upon exposure to DFP, DFM, DFP plus FeCl
3
, or FeCl
3
alone. A preformed biofilm was exposed to DFP with or without FeCl
3
. The DFP and DFS MIC
50
against planktonic
A. fumigatus
was 1,250 μM, and XTT gave the same result. DFM showed no planktonic inhibition at concentrations of ≤2,500 μM. By XTT testing, DFM concentrations of <1,250 μM had no effect, whereas 2,500 μM increased biofilms forming in
A. fumigatus
or preformed biofilms (
P
< 0.01). DFP at 156 to 2,500 μM inhibited biofilm formation (
P
< 0.01 to 0.001) in a dose-responsive manner. Biofilm formation with 625 μM DFP plus any concentration of FeCl
3
was lower than that in the controls (
P
< 0.05 to 0.001). FeCl
3
at ≥625 μM reversed the DFP inhibitory effect (
P
< 0.05 to 0.01), but the reversal was incomplete compared to the controls (
P
< 0.05 to 0.01). For preformed biofilms, DFP in the range of ≥625 to 1,250 μM was inhibitory compared to the controls (
P
< 0.01 to 0.001). FeCl
3
at ≥625 μM overcame inhibition by 625 μM DFP (
P
< 0.001). FeCl
3
alone at ≥156 μM stimulated biofilm formation (
P
< 0.05 to 0.001). Preformed
A. fumigatus
biofilm increased with 2,500 μM FeCl
3
only (
P
< 0.05). In a strain survey, various susceptibilities of biofilms of
A. fumigatus
clinical isolates to DFP were noted. In conclusion, iron stimulates biofilm formation and preformed biofilms. Chelators can inhibit or enhance biofilms. Chelation may be a potential therapy for
A. fumigatus
, but we show here that chelators must be chosen carefully. Individual isolate susceptibility assessments may be needed.
Comparative Genomics Provides Insight into the Diversity of the Attaching and Effacing Escherichia coli Virulence Plasmids
Authors: Hazen Tracy H. , Kaper James B. , Nataro James P. , Rasko David A.
Published: August 2015

Attaching and effacing
Escherichia coli
(AEEC) strains are a genomically diverse group of diarrheagenic
E. coli
strains that are characterized by the presence of the locus of enterocyte effacement (LEE) genomic island, which encodes a type III secretion system that is essential to virulence. AEEC strains can be further classified as either enterohemorrhagic
E. coli
(EHEC), typical enteropathogenic
E. coli
(EPEC), or atypical EPEC, depending on the presence or absence of the Shiga toxin genes or bundle-forming pilus (BFP) genes. Recent AEEC genomic studies have focused on the diversity of the core genome, and less is known regarding the genetic diversity and relatedness of AEEC plasmids. Comparative genomic analyses in this study demonstrated genetic similarity among AEEC plasmid genes involved in plasmid replication conjugative transfer and maintenance, while the remainder of the plasmids had sequence variability. Investigation of the EPEC adherence factor (EAF) plasmids, which carry the BFP genes, demonstrated significant plasmid diversity even among isolates within the same phylogenomic lineage, suggesting that these EAF-like plasmids have undergone genetic modifications or have been lost and acquired multiple times. Global transcriptional analyses of the EPEC prototype isolate E2348/69 and two EAF plasmid mutants of this isolate demonstrated that the plasmid genes influence the expression of a number of chromosomal genes in addition to the LEE. This suggests that the genetic diversity of the EAF plasmids could contribute to differences in the global virulence regulons of EPEC isolates.
Opposite and Coordinated Rotation of Amphitrichous Flagella Governs Oriented Swimming and Reversals in a Magnetotactic Spirillum
Authors: Murat Dorothée , Hérisse Marion , Espinosa Leon , Bossa Alicia , Alberto François , Wu Long-Fei
Published: August 2015

Current knowledge regarding the mechanism that governs flagellar motor rotation in response to environmental stimuli stems mainly from the study of monotrichous and peritrichous bacteria. Little is known about how two polar flagella, one at each cell pole of the so-called amphitrichous bacterium, are coordinated to steer the swimming. Here we fluorescently labeled the flagella of
Magnetospirillum magneticum
AMB-1 cells and took advantage of the magnetically controllable swimming of this bacterium to investigate flagellar rotation in moving cells. We identified three motility behaviors (runs, tumbles, and reversals) and two characteristic fluorescence patterns likely corresponding to flagella rotating in opposite directions. Each AMB-1 locomotion mode was systematically associated with particular flagellar patterns at the poles which led us to conclude that, while cell runs are allowed by the asymmetrical rotation of flagellar motors, their symmetrical rotation triggers cell tumbling. Our observations point toward a precise coordination of the two flagellar motors which can be temporarily unsynchronized during tumbling.

IMPORTANCE
Motility is essential for bacteria to search for optimal niches and survive. Many bacteria use one or several flagella to explore their environment. The mechanism by which bipolarly flagellated cells coordinate flagellar rotation is poorly understood. We took advantage of the genetic amenability and magnetically controlled swimming of the spirillum-shaped magnetotactic bacterium
Magnetospirillum magneticum
AMB-1 to correlate cell motion with flagellar rotation. We found that asymmetric rotation of the flagella (counterclockwise at the lagging pole and clockwise at the leading pole) enables cell runs whereas symmetric rotation triggers cell tumbling. Taking into consideration similar observations in spirochetes, bacteria possessing bipolar ribbons of periplasmic flagella, we propose a conserved motility paradigm for spirillum-shaped bipolarly flagellated bacteria.