bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of realimentation after nutrient restriction during mid‐ to late gestation on pancreatic digestive enzymes, serum insulin and glucose levels, and insulin‐containing cell cluster morphology
Authors: Keomanivong F. E. , Camacho L. E. , Lemley C. O. , Kuemper E. A. , Yunusova R. D. , Borowicz P. P. , Kirsch J. D. , Vonnahme K. A. , Caton J. S. , Swanson K. C.
Published: April 2016

This study examined effects of stage of gestation and nutrient restriction with subsequent realimentation on maternal and foetal bovine pancreatic function. Dietary treatments were assigned on day 30 of pregnancy and included: control (CON; 100% requirements; n = 18) and restricted (R; 60% requirements; n = 30). On day 85, cows were slaughtered (CON, n = 6; R, n = 6), remained on control (CC; n = 12) and restricted (RR; n = 12), or realimented to control (RC; n = 11). On day 140, cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remained on control (CCC, n = 6; RCC, n = 5) or realimented to control (RRC, n = 6). On day 254, the remaining cows were slaughtered and serum samples were collected from the maternal jugular vein and umbilical cord to determine insulin and glucose concentrations. Pancreases from cows and foetuses were removed, weighed, and subsampled for enzyme and histological analysis. As gestation progressed, maternal pancreatic α‐amylase activity decreased and serum insulin concentrations increased (p ≤ 0.03). Foetal pancreatic trypsin activity increased (p < 0.001) with advancing gestation. Foetal pancreases subjected to realimentation (CCC vs. RCC and RRC) had increased protein and α‐amylase activity at day 254 (p ≤ 0.02), while trypsin (U/g protein; p = 0.02) demonstrated the opposite effect. No treatment effects were observed for maternal or foetal pancreatic insulin‐containing cell clusters. Foetal serum insulin and glucose levels were reduced with advancing gestation (p ≤ 0.03). The largest maternal insulin‐containing cell cluster was not influenced by advancing gestation, while foetal clusters grew throughout (p = 0.01). These effects indicate that maternal digestive enzymes are influenced by nutrient restriction and there is a potential for programming of increased foetal digestive enzyme production resulting from previous maternal nutrient restriction.
Uncertainty, Flexible Labour Relations and R&D
Authors: Di Cintio Marco , Grassi Emanuele
Published: April 2016

This paper examines the effects of uncertainty and flexible labour contracts on the Research and Development (R&D) intensity. Using a panel of Italian manufacturing firms, we find a hump‐shaped relationship between workforce flexibility and R&D intensity. Moreover, as predicted by the real options theory, our results suggest that product market uncertainty reduces R&D efforts and that flexible labour contracts countervail the adverse effect of uncertainty on R&D.
South Korea and Japan since World War II: Between Ideological Discord and Pragmatic Cooperation
Authors: Horowitz Shale
Published: April 2016

Since the end of World War II, relations between South Korea and Japan have gone through significant changes – from distant and hostile in the 1950s, to cooperative and increasingly close through about 2005, to the last decade of serious deterioration. Three frameworks are used to understand change and continuity in South Korea–Japan relations: a realist perspective emphasizing either structural military power relations or “revealed” patterns of military threat; an institutional perspective that emphasizes similarities or differences in political institutions; and an ideological regime‐type perspective that includes ideologies as well as institutions as influences on government or leadership preferences. The third framework captures two types of ideological factors that have exerted significant influences on South Korea–Japan relations: the existence of a small range of competitive ideological regime types or government types specifying national ideals and national development roadmaps; and historical legacies of intense conflict, which tend to produce ideological and diversionary frictions that cause conflict to persist or recur. Only the last factor, the history issue, is readily subject to policy control: the best way forward to restore cooperative and stable relations is for South Korean and Japanese leaders to agree informally on truthful and empathetic norms governing historical judgments, and for Japanese political and opinion elites to agree informally to marginalize those that defy such norms.
Reloca Slide: an ~24 km3 submarine mass‐wasting event in response to over‐steepening and failure of the central Chilean continental slope
Authors: Contreras‐Reyes Eduardo , Völker David , Bialas Jörg , Moscoso Eduardo , Grevemeyer Ingo
Published: April 2016

Reloca Slide is the relict of an ~24‐km3 submarine slope collapse at the base of the convergent continental margin of central Chile. Bathymetric and seismic data show that directly to the north and south of the slide the lower continental slope is steep (~10°), the deformation front is shifted landwards by 10–15 km, and the frontal accretionary prism is uplifted. In contrast, ~80 km to the north the lower continental margin presents a lower slope angle of about 4° and a wide frontal accretionary prism. We propose that high effective basal friction conditions at the base of the accretionary prism favoured basal accretion of sediment and over‐steepening of the continental slope, producing massive submarine mass wasting in the Reloca region. This area also spatially correlates with a zone of low coseismic slip of the 2010 Maule megathrust earthquake, which is consistent with high basal frictional coefficients.
Two human immunodeficiency virus Type 2 cases in US blood donors including serologic, molecular, and genomic characterization of an epidemiologically unusual case
Authors: Stramer Susan L. , Yu Guixia , Herron Ross , Espinoza Norma , Foster Gregory A. , Naccache Samia N. , Brodsky Jaye P. , Ong Edgar , Linnen Jeffrey M. , Dyer Nicole , Styer Linda M. , Parker Monica M. , Chiu Charles Y.
Published: April 2016

BACKGROUND

Blood donation screening for human immunodeficiency virus Type 2 (HIV‐2) has been in place in the United States since 1992. However, only three HIV‐2 antibody–positive donors have been reported to date, all detected via HIV‐1 cross‐reactivity.

STUDY DESIGN AND METHODS

Here we identify two additional HIV‐2–positive donors by routine anti‐HIV‐1 and anti‐HIV‐2 screening, including a first‐time male donor living in Georgia having recently immigrated to the United States from West Africa (from a 1998 donation) and a Taiwanese female repeat donor (nurse) living in California with no travel outside of Taiwan or apparent connections to West Africa (from a 2015 donation). Neither donor acknowledged any risk factors, and both remained asymptomatic through follow‐up. The second donor was further investigated by serologic, molecular, and genomic assays because of her unusual demographics. She was documented to harbor HIV‐2 RNA, albeit sporadically by HIV‐2–specific nucleic acid tests (35%‐100% of replicates) and at very low levels (<9.6 IU/mL). Metagenomic next‐generation sequencing (mNGS) confirmed the identification of a Group B HIV‐2 strain, with recovered reads covering 46.9% of the predicted genome.

CONCLUSIONS

The estimated frequency of an HIV‐2–positive blood donor in the United States is one in 57 million donations. Due to the low frequency and low pathogenicity of HIV‐2, public health and blood donation screening efforts must focus on HIV‐1 detection and prevention. However, detection of HIV‐2 infection in a donor with no apparent link to West Africa suggests that the United States must remain vigilant for HIV‐2 virus infections. Ultradeep mNGS may be useful in the future for comprehensive identification of rare transfusion‐transmissible agents.
Postnatal cytomegalovirus infection: a pilot comparative effectiveness study of transfusion safety using leukoreduced‐only transfusion strategy
Authors: Delaney Meghan , Mayock Dennis , Knezevic Andrea , Norby‐Slycord Colette , Kleine Elizabeth , Patel Ravi , Easley Kirk , Josephson Cassandra
Published: April 2016

BACKGROUND

The optimal mitigation strategy to prevent transfusion transmission of cytomegalovirus (TT‐CMV) in preterm very low birthweight infants remains debated. Hospitals caring for this patient population have varied practices.

STUDY DESIGN AND METHODS

A prospective observational comparative effectiveness pilot study was conducted to determine the feasibility for a larger study. The pilot was carried out at hospitals using a leukoreduction (LR)‐only transfusion strategy. Specimen and data collection for this study was performed in a similar approach to a study completed at Emory University that employed the CMV‐seronegative plus LR approach. All testing was performed at one laboratory. The rates of TT‐CMV using the two transfusion strategies were compared.

RESULTS

Zero incidence of TT‐CMV was detected in infants (n = 20) transfused with LR‐only blood (0/8; 95% confidence interval [CI], 0‐25.3%) and is consistent with the previously reported zero incidence of TT‐CMV finding in a cohort of infants transfused with CMV‐negative plus LR blood (0/310; 95% CI, 0%‐0.9%). The seroprevalence rate among enrolled mothers (n = 17) was 60%. Forty percent of those infants (8/20) received 43 transfusions; five were transfused with one or more CMV‐seropositive blood components. One infant had tested positive for CMV before receiving blood transfusions; the infant's mother was CMV immunoglobulin (Ig)G positive and IgM negative.

CONCLUSIONS

Using the LR‐only transfusion approach, zero cases of TT‐CMV were detected in this pilot study. A larger study is needed to reliably determine the most effective strategy for prevention of TT‐CMV in this population.
Hair transplantation in mice: Challenges and solutions
Authors: Asgari Azar Z , Rufaut Nicholas. W. , Morrison Wayne A. , Dilley Rodney. J. , Knudsen Russle , Jones Leslie N. , Sinclair Rodney. D.
Published: April 2016

Hair follicle cells contribute to wound healing, skin circulation, and skin diseases including skin cancer, and hair transplantation is a useful technique to study the participation of hair follicle cells in skin homeostasis and wound healing. Although hair follicle transplantation is a well‐established human hair‐restoration procedure, follicular transplantation techniques in animals have a number of shortcomings and have not been well described or optimized. To facilitate the study of follicular stem and progenitor cells and their interaction with surrounding skin, we have established a new murine transplantation model, similar to follicular unit transplantation in humans. Vibrissae from GFP transgenic mice were harvested, flip‐side microdissected, and implanted individually into needle hole incisions in the back skin of immune‐deficient nude mice. Grafts were evaluated histologically and the growth of transplanted vibrissae was observed. Transplanted follicles cycled spontaneously and newly formed hair shafts emerged from the skin after 2 weeks. Ninety percent of grafted vibrissae produced a hair shaft at 6 weeks. After pluck‐induced follicle cycling, growth rates were equivalent to ungrafted vibrissae. Transplanted vibrissae with GFP‐positive cells were easily identified in histological sections. We established a follicular vibrissa transplantation method that recapitulates human follicular unit transplantation. This method has several advantages over current protocols for animal hair transplantation. The method requires no suturing and minimizes the damage to donor follicles and recipient skin. Vibrissae are easier to microdissect and transplant than pelage follicles and, once transplanted, are readily distinguished from host pelage hair. This facilitates measurement of hair growth. Flip‐side hair follicle microdissection precisely separates donor follicular tissue from interfollicular tissue and donor cells remain confined to hair follicles. This makes it possible to differentiate migration of hair follicle cells from interfollicular epidermis in lineage tracing wound experiments using genetically labeled donor follicles.
Structure of the maximal -local geometry point-line collinearity graph
Authors: Rowley Peter , Wright Ben
Published: April 2016

The point-line collinearity graph${\mathcal{G}}$of the maximal 2-local geometry for the largest simple Fischer group,$Fi_{24}^{\prime }$, is extensively analysed. For an arbitrary vertex$a$of${\mathcal{G}}$, the$i\text{th}$-disc of$a$is described in detail. As a consequence, it follows that${\mathcal{G}}$has diameter$5$. The collapsed adjacency matrix of${\mathcal{G}}$is given as well as accompanying computer files which contain a wealth of data about${\mathcal{G}}$.

Supplementary materials are available with this article.
Extrusion versus diffusion: mechanisms for recovery from sodium loads in mouse CA1 pyramidal neurons
Authors: Mondragão Miguel A. , Schmidt Hartmut , Kleinhans Christian , Langer Julia , Kafitz Karl W. , Rose Christine R.
Published: April 2016

Key points

Neuronal activity causes local or global sodium signalling in neurons, depending on the pattern of synaptic activity.

Recovery from global sodium loads critically relies on Na+/K+‐ATPase and an intact energy metabolism in both somata and dendrites.

For recovery from local sodium loads in dendrites, Na+/K+‐ATPase activity is not required per se. Instead, recovery is predominately mediated by lateral diffusion, exhibiting rates that are 10‐fold higher than for global sodium signals.

Recovery from local dendritic sodium increases is still efficient during short periods of energy deprivation, indicating that fast diffusion of sodium to non‐stimulated regions strongly reduces local energy requirements.

Excitatory activity is accompanied by sodium influx into neurones as a result of the opening of voltage‐ and ligand‐activated channels. Recovery from resulting sodium transients has mainly been attributed to Na+/K+‐ATPase (NKA). Because sodium ions are highly mobile, diffusion could provide an additional pathway. We tested this in hippocampal neurones using whole‐cell patch‐clamp recordings and sodium imaging. Somatic sodium transients induced by local glutamate application recovered at a maximum rate of 8 mm min−1 (∼0.03 mm min−1 μm−2). Somatic sodium extrusion was accelerated at higher temperature and blocked by ouabain, emphasizing its dependence on NKA. Moreover, it was slowed down during inhibition of glycolysis by sodium fluoride (NaF). Local glutamate application to dendrites revealed a 10‐fold higher apparent dendritic sodium extrusion rate compared to somata. Recovery was almost unaltered by increased temperature, ouabain or NaF. We found that sodium diffused along primary dendrites with a diffusion coefficient of ∼330 μm²/s. During global glutamate application, impeding substantial net diffusion, apparent dendritic extrusion rates were reduced to somatic rates and also affected by NaF. Numerical simulations confirmed the essential role of NKA for the recovery of somatic, but not dendritic sodium loads. Our data show that sodium export upon global sodium increases is largely mediated by NKA and depends on an intact energy metabolism. For recovery from local dendritic sodium increases, diffusion dominates over extrusion, operating efficiently even during short periods of energy deprivation. Although sodium will eventually be extruded by the NKA, its diffusion‐based fast dissemination to non‐stimulated regions might reduce local energy requirements.
Proposal of a non-lethal visual census method to estimate freshwater stingray abundance
Authors: Morales-Betancourt Mónica Andrea , Lasso-Alcalá Carlos Andrés
Published: April 2016

There is not a current method to estimate South American freshwater stingray’s abundance. Therefore we designed a census method and tested it in the field. It consists of making nocturnal surveys by boat in large rivers (>25m width) and floodplain lagoons of varying sizes, along transects of 100m x 10m (1000 m2). We applied this method in the Tomo River, a tributary of the Orinoco River in Colombia. 110 transects were surveyed in 200 runs. A total of 149 rays of four species were recorded: Potamotrygon motoro, Potamotrygon orbignyi, Potamotrygon schroederi and Paratrygon aiereba. P. motoro was the most abundant with a density of 0.31 individuals /1000 m2 (SD=0.5). This method gave optimal results when applied to habitats with high transparency and shallow depth (< 1m) since it permitted the identification of both adults and juveniles present.
Modeling and Analysis of Multilayered Elastic Beam Using Spectral Finite Element Method
Authors: Unal Ahmet , Wang Gang , Zuo Q. H.
Published: April 2016

Multilayered elastic structures are widely used in engineering applications. In this paper, a spectral finite element model (SFEM) is developed to predict the dynamic behavior of a multilayered beam structure. First, a higher-order multilayered beam model is derived. Each layer is modeled as a Timoshenko beam, in which both shear deformation and rotational inertia are considered. By allowing different rotation in each layer, the overall sectional warping effect is included as well. A set of fully coupled governing equations presented in a compact form and associated boundary conditions are obtained by the application of Hamilton's principle. Second, a semi-analytical solution of these equations is determined and used in formulating the SFEM. The SFEM predictions are validated against the nastran results and other results in literature. Compared to the conventional FEM (CFEM), a very small number of elements are required in the SFEM for comparable accuracy, which substantially reduce the computing time, especially for simulations of high-frequency wave propagations. Finally, the SFEM is used to predict the lamb wave responses in multilayered beams. Wave propagation characteristics in both undamaged and damaged cases are well captured. In summary, the SFEM can accurately and efficiently predict the behavior of multilayered beams and serve as a framework to conduct wave propagation prediction and damage diagnostic analysis in structural health monitoring (SHM) applications.
A Note on Heat Transfer Enhancement in Laminar Impinging Flows With Shear Thinning Inelastic Fluids
Authors: Chatterjee Ajay , Fabris Drazen
Published: April 2016

A recent article presented axisymmetric numerical calculations showing substantial heat transfer enhancement in a laminar impinging flow with shear thinning inelastic fluids. This paper compares enhancement in planar and axisymmetric geometries and presents empirical dependencies correlating heat transfer rates to fluid rheology. The parametric correlation is expressed in the form ∼ ReGp. ReG is a generalized Reynolds number based on the reference strain rate and fluid rheology, and it is larger than the Newtonian Reynolds number for the same mean nozzle velocity and flow geometry. The value of p > 0 is estimated from the numerical data for weak and strong shear thinning. Within the impinging zone spanning the nozzle cross section, the value of p is essentially similar for both geometries, but in the wall jet the planar flow shows a somewhat larger value. The total heat transfer rate in the planar wall jet may be two to ten times larger for a shear thinning fluid. This is because in shear thinning flow, the primary separation vortex is able to maintain the Nusselt number at a higher average value over a significantly longer length scale in the streamwise direction.
Synthesis of C0 Path-Generating Contact-Aided Compliant Mechanisms Using the Material Mask Overlay Method
Authors: Kumar Prabhat , Sauer Roger A. , Saxena Anupam
Published: April 2016

Contact-aided compliant mechanisms (CCMs) are synthesized via the material mask overlay strategy (MMOS) to trace desired nonsmooth paths. MMOS employs hexagonal cells to discretize the design region and engages negative circular masks to designate material states. To synthesize CCMs, the modified MMOS presented herein involves systematic mutation of five mask parameters through a hill climber search to evolve not only the continuum topology but also to position the rigid, interacting surfaces within some masks. To facilitate analysis with contact, boundary smoothing is performed by shifting boundary nodes of the evolving continuum. Various geometric singularities are subdued via hexagonal cells, and the V-notches at the continuum boundaries are alleviated. Numerous hexagonal cells get morphed into concave subregions as a consequence. Large deformation finite-element formulation with mean-value coordinates based shape functions is used to cater to the generic hexagonal shapes. Contact analysis is accomplished via the Newton–Raphson (NR) iteration with load incrementing in conjunction with the augmented Lagrange multiplier method and active set constraints. An objective function based on Fourier shape descriptors (FSDs) is minimized subject to suitable design constraints. Two examples of path-generating CCMs are presented, their performance compared with a commercial software and fabricated to establish the efficacy of the proposed synthesis method.
Compression Garments, Muscle Contractile Function, and Economy in Trail Runners
Authors: Vercruyssen Fabrice , Gruet Mathieu , Colson Serge S. , Ehrstrom Sabine , Brisswalter Jeanick
Published: April 2016

Background:

Physiological mechanisms behind the use of compression garments (CGs) during off-road running are unknown.

Purpose:

To investigate the influence of wearing CGs vs conventional running clothing (CON) on muscle contractile function and running economy before and after short-distance trail running.

Methods:

Knee-extensor neuromuscular function and running economy assessed from two 5-min treadmill runs (11 and 14 km/h) were evaluated before and after an 18.6-km short-distance trail run in 12 trained athletes wearing either CGs (stocking + short-tight) or CON. Quadriceps neuromuscular function was assessed from mechanical and EMG recording after maximal percutaneous electrical femoral-nerve stimulations (single-twitch doublets at 10 [Db10] and 100 Hz [Db100] delivered at rest and during maximal quadriceps voluntary contraction [MVC]).

Results:

Running economy (in mL O2 · km–1 · kg–1) increased after trail running independent of the clothing condition and treadmill speeds (P < .001). Similarly, MVC decreased after CON and CGs conditions (–11% and –13%, respectively, P < .001). For both clothing conditions, a significant decrease in quadriceps voluntary activation, Db10, Db100, and the low-to-high frequency doublet ratio were observed after trail running (time effect, all P < .01), without any changes in rectus femoris maximal M-wave.

Conclusions:

Wearing CGs does not reduce physiological alterations induced during short-distance trail running. Further studies should determine whether higher intensity of compression pressure during exercises of longer duration may be effective to induce any physiological benefits in experienced trail runners.
Amino Acid Substitutions of CrrB Responsible for Resistance to Colistin through CrrC in Klebsiella pneumoniae
Authors: Cheng Yi-Hsiang , Lin Tzu-Lung , Lin Yi-Tsung , Wang Jin-Town
Published: April 2016

Colistin is a last-resort antibiotic for treatment of carbapenem-resistant
Klebsiella pneumoniae
. A recent study indicated that missense mutations in the CrrB protein contribute to colistin resistance. In our previous study, mechanisms of colistin resistance were defined in 17 of 26 colistin-resistant
K. pneumoniae
clinical isolates. Of the remaining nine strains, eight were highly resistant to colistin. In the present study,
crrAB
sequences were determined for these eight strains. Six separate amino acid substitutions in CrrB (Q10L, Y31H, W140R, N141I, P151S, and S195N) were detected. Site-directed mutagenesis was used to generate
crrB
loci harboring individual missense mutations; introduction of the mutated genes into a susceptible strain, A4528, resulted in 64- to 1,024-fold increases in colistin MICs. These
crrB
mutants showed increased accumulation of
H239_3062
,
H239_3059
,
pmrA
,
pmrC
, and
pmrH
transcripts by quantitative reverse transcription (qRT)-PCR. Deletion of
H239_3062
(but not that of
H239_3059
) in the A4528
crrB
(
N141I
) strain attenuated resistance to colistin, and
H239_3062
was accordingly named
crrC
. Similarly, accumulation of
pmrA
,
pmrC
, and
pmrH
transcripts induced by
crrB
(
N141I
) was significantly attenuated upon deletion of
crrC
. Complementation of
crrC
restored resistance to colistin and accumulation of
pmrA
,
pmrC
, and
pmrH
transcripts in a
crrB
(
N141I
) Δ
crrC
strain. In conclusion, novel individual CrrB amino acid substitutions (Y31H, W140R, N141I, P151S, and S195N) were shown to be responsible for colistin resistance. We hypothesize that CrrB mutations induce CrrC expression, thereby inducing elevated expression of the
pmrHFIJKLM
operon and
pmrC
(an effect mediated via the PmrAB two-component system) and yielding increased colistin resistance.
Molecular Epidemiology and Genetic Characteristics of Various
bla
PER
Genes in Shanghai, China
Authors: Xie Lianyan , Wu Jun , Zhang Fangfang , Han Lizhong , Guo Xiaokui , Ni Yuxing , Sun Jingyong
Published: April 2016

We describe the genetic characteristics and possible transmission mechanism of
bla
PER
in 25 clinical Gram-negative bacilli in Shanghai.
bla
PER
, including
bla
PER-1
,
bla
PER-3
, and
bla
PER-4
, was located chromosomally or in different plasmids. Tn
1213
harboring
bla
PER-1
was first identified in two
Proteus mirabilis
isolates in China. The other
bla
PER
variants were preceded by an IS
CR1
element inside the complex class 1 integron associated with IS
26
, Tn
21
, Tn
1696
, and a miniature inverted-repeat transposable element.
New Role for FDA-Approved Drugs in Combating Antibiotic-Resistant Bacteria
Authors: Andersson Jourdan A. , Fitts Eric C. , Kirtley Michelle L. , Ponnusamy Duraisamy , Peniche Alex G. , Dann Sara M. , Motin Vladimir L. , Chauhan Sadhana , Rosenzweig Jason A. , Sha Jian , Chopra Ashok K.
Published: April 2016

Antibiotic resistance in medically relevant bacterial pathogens, coupled with a paucity of novel antimicrobial discoveries, represents a pressing global crisis. Traditional drug discovery is an inefficient and costly process; however, systematic screening of Food and Drug Administration (FDA)-approved therapeutics for other indications in humans offers a rapid alternative approach. In this study, we screened a library of 780 FDA-approved drugs to identify molecules that rendered RAW 264.7 murine macrophages resistant to cytotoxicity induced by the highly virulent
Yersinia pestis
CO92 strain. Of these compounds, we identified 94 not classified as antibiotics as being effective at preventing
Y. pestis
-induced cytotoxicity. A total of 17 prioritized drugs, based on efficacy in
in vitro
screens, were chosen for further evaluation in a murine model of pneumonic plague to delineate if
in vitro
efficacy could be translated
in vivo
. Three drugs, doxapram (DXP), amoxapine (AXPN), and trifluoperazine (TFP), increased animal survivability despite not exhibiting any direct bacteriostatic or bactericidal effect on
Y. pestis
and having no modulating effect on crucial
Y. pestis
virulence factors. These findings suggested that DXP, AXPN, and TFP may modulate host cell pathways necessary for disease pathogenesis. Finally, to further assess the broad applicability of drugs identified from
in vitro
screens, the therapeutic potential of TFP, the most efficacious drug
in vivo
, was evaluated in murine models of
Salmonella enterica
serovar Typhimurium and
Clostridium difficile
infections. In both models, TFP treatment resulted in increased survivability of infected animals. Taken together, these results demonstrate the broad applicability and potential use of nonantibiotic FDA-approved drugs to combat respiratory and gastrointestinal bacterial pathogens.
Clomipramine and Benznidazole Act Synergistically and Ameliorate the Outcome of Experimental Chagas Disease
Authors: García Mónica Cristina , Ponce Nicolás Eric , Sanmarco Liliana Maria , Manzo Rubén Hilario , Jimenez-Kairuz Alvaro Federico , Aoki Maria Pilar
Published: April 2016

Chagas disease is an important public health problem in Latin America, and its treatment by chemotherapy with benznidazole (BZ) or nifurtimox remains unsatisfactory. In order to design new alternative strategies to improve the current etiological treatments, in the present work, we comprehensively evaluated thein vitroandin vivoanti-Trypanosoma cruzieffects of clomipramine (CMP) (a parasite-trypanothione reductase-specific inhibitor) combined with BZ.In vitrostudies, carried out using a checkerboard technique on trypomastigotes (T. cruzistrain Tulahuen), revealed a combination index (CI) of 0.375, indicative of a synergistic effect of the drug combination. This result was correlated with the data obtained in infected BALB/c mice. We observed that during the acute phase (15 days postinfection [dpi]), BZ at 25 mg/kg of body weight/day alone decreased the levels of parasitemia compared with those of the control group, but when BZ was administered with CMP, the drug combination completely suppressed the parasitemia due to the observed synergistic effect. Furthermore, in the chronic phase (90 dpi), mice treated with both drugs showed less heart damage as assessed by the histopathological analysis, index of myocardial inflammation, and levels of heart injury biochemical markers than mice treated with BZ alone at the reference dose (100 mg/kg/day). Collectively, these data support the notion that CMP combined with low doses of BZ diminishes cardiac damage and inflammation during the chronic phase of cardiomyopathy. The synergistic activity of BZ-CMP clearly suggests a potential drug combination for Chagas disease treatment, which would allow a reduction of the effective dose of BZ and an increase in therapeutic safety.
Population Pharmacokinetics Analysis To Inform Efavirenz Dosing Recommendations in Pediatric HIV Patients Aged 3 Months to 3 Years
Authors: Luo Man , Chapel Sunny , Sevinsky Heather , Savant Ishani , Cirincione Brenda , Bertz Richard , Roy Amit
Published: April 2016

Efavirenz (EFV) is a nonnucleoside reverse transcriptase inhibitor approved worldwide for the treatment of HIV in adults and children over 3 years of age or weighing over 10 kg. Only recently EFV was approved in children over 3 months and weighing at least 3.5 kg in the United States and the European Union. The objective of this analysis was to support the selection of an appropriate dose for this younger pediatric population and to explore the impact of CYP2B6 genetic polymorphisms on EFV systemic exposures. A population pharmacokinetic (PPK) model was developed using data from three studies in HIV-1-infected pediatric subjects (
n
= 168) and one study in healthy adults (
n
= 24). The EFV concentration-time profile was best described by a two-compartment model with first-order absorption and elimination. Body weight was identified as a significant predictor of efavirenz apparent clearance (CL), oral central volume of distribution (

V
C

), and absorption rate constant (

K
a

). The typical values of efavirenz apparent CL,

V
C

, oral peripheral volume of distribution (

V
P

), and

K
a

for a reference pediatric patient were 4.8 liters/h (4.5 to 5.1 liters/h), 84.9 liters (76.8 to 93.0 liters), 287 liters (252.6 to 321.4 liters), and 0.414 h
−1
(0.375 to 0.453 h
−1
), respectively. The final model was used to simulate steady-state efavirenz concentrations in pediatric patients weighing <10 kg to identify EFV doses that produce comparable exposure to adult and pediatric patients weighing ≥10 kg. Results suggest that administration of EFV doses of 100 mg once daily (QD) to children weighing ≥3.5 to <5 kg, 150 mg QD to children weighing ≥5 to <7.5 kg, and 200 mg QD to children weighing ≥7.5 to <10 kg produce exposures within the target range. Further evaluation of the impact of CYP2B6 polymorphisms on EFV PK showed that the identification of CYP2B6 genetic status is not predictive of EFV exposure and thus not informative to guide pediatric dosing regimens.
Moxifloxacin's Limited Efficacy in the Hollow-Fiber Model of Mycobacterium abscessus Disease
Authors: Ferro Beatriz E. , Srivastava Shashikant , Deshpande Devyani , Pasipanodya Jotam G. , van Soolingen Dick , Mouton Johan W. , van Ingen Jakko , Gumbo Tawanda
Published: April 2016

Current regimens used to treat pulmonary
Mycobacterium abscessus
disease have limited efficacy. There is an urgent need for new drugs and optimized combinations and doses. We performed hollow-fiber-system studies in which
M. abscessus
was exposed to moxifloxacin lung concentration-time profiles similar to human doses of between 0 and 800 mg/day. The minimum bactericidal concentration and MIC were 8 and 2 mg/liter, respectively, in our
M. abscessus
strain, suggesting bactericidal activity. Measurement of the moxifloxacin concentrations in each hollow-fiber system revealed an elimination rate constant (
k
el
) of 0.11 ± 0.05 h
−1
(mean ± standard deviation) (half-life of 9.8 h). Inhibitory sigmoid maximal effect (
E
max
) modeling revealed that the highest
E
max
was 3.15 ± 1.84 log
10
CFU/ml on day 3, and the exposure mediating 50% of
E
max
(EC
50
) was a 0- to 24-h area under the concentration time curve (AUC
0–24
)-to-MIC ratio of 41.99 ± 31.78 (
r
2
= 0.99). The EC
80
was an AUC
0–24
/MIC ratio of 102.11. However, no moxifloxacin concentration killed the bacteria to burdens below the starting inoculum. There was regrowth beyond day 3 in all doses, with replacement by a resistant subpopulation that had an MIC of >32 mg/liter by the end of the experiment. A quadratic function best described the relationship between the AUC
0–24
/MIC ratio and the moxifloxacin-resistant subpopulation. Monte Carlo simulations of 10,000 patients revealed that the 400- to 800-mg/day doses would achieve or exceed the EC
80
in ≤12.5% of patients. The moxifloxacin susceptibility breakpoint was 0.25 mg/liter, which means that almost all
M. abscessus
clinical strains are moxifloxacin resistant by these criteria. While moxifloxacin's efficacy against
M. abscessus
was poor, formal combination therapy studies with moxifloxacin are still recommended.
Paradoxical Effect of Polymyxin B: High Drug Exposure Amplifies Resistance in Acinetobacter baumannii
Authors: Tsuji Brian T. , Landersdorfer Cornelia B. , Lenhard Justin R. , Cheah Soon-Ee , Thamlikitkul Visanu , Rao Gauri G. , Holden Patricia N. , Forrest Alan , Bulitta Jürgen B. , Nation Roger L. , Li Jian
Published: April 2016

Administering polymyxin antibiotics in a traditional fashion may be ineffective against Gram-negative ESKAPE (
Enterococcus faecium
,
Staphylococcus aureus
,
Klebsiella pneumoniae
,
Acinetobacter baumannii
,
Pseudomonas aeruginosa
, and
Enterobacter
species) pathogens. Here, we explored increasing the dose intensity of polymyxin B against two strains of
Acinetobacter baumannii
in the hollow-fiber infection model. The following dosage regimens were simulated for polymyxin B (
t
1/2
= 8 h): non-loading dose (1.43 mg/kg of body weight every 12 h [q12h]), loading dose (2.22 mg/kg q12h for 1 dose and then 1.43 mg/kg q12h), front-loading dose (3.33 mg/kg q12h for 1 dose followed by 1.43 mg/kg q12h), burst (5.53 mg/kg for 1 dose), and supraburst (18.4 mg/kg for 1 dose). Against both
A. baumannii
isolates, a rapid initial decline in the total population was observed within the first 6 h of polymyxin exposure, whereby greater polymyxin B exposure resulted in greater maximal killing of −1.25, −1.43, −2.84, −2.84, and −3.40 log
10
CFU/ml within the first 6 h. Unexpectedly, we observed a paradoxical effect whereby higher polymyxin B exposures dramatically increased resistant subpopulations that grew on agar containing up to 10 mg/liter of polymyxin B over 336 h. High drug exposure also proliferated polymyxin-dependent growth. A cost-benefit pharmacokinetic/pharmacodynamic relationship between 24-h killing and 336-h resistance was explored. The intersecting point, where the benefit of bacterial killing was equal to the cost of resistance, was an
f
AUC
0–24
(area under the concentration-time curve from 0 to 24 h for the free, unbound fraction of drug) of 38.5 mg · h/liter for polymyxin B. Increasing the dose intensity of polymyxin B resulted in amplification of resistance, highlighting the need to utilize polymyxins as part of a combination against high-bacterial-density
A. baumannii
infections.
Efficacy of Lantibiotic Treatment of Staphylococcus aureus-Induced Skin Infections, Monitored byIn VivoBioluminescent Imaging
Authors: van Staden Anton Du Preez , Heunis Tiaan , Smith Carine , Deane Shelly , Dicks Leon M. T.
Published: April 2016

Staphylococcus aureusis a bacterial pathogen responsible for the majority of skin and soft tissue infections. Antibiotics are losing their efficacy as treatment for skin and soft tissue infections as a result of increased resistance in a variety of pathogens, includingS. aureus. It is thus imperative to explore alternative antimicrobial treatments to ensure future treatment options for skin and soft tissue infections. A select few lantibiotics, a group of natural defense peptides produced by bacteria, inhibit the growth of numerous clinicalS. aureusisolates, including methicillin-resistant strains. In this study, the antimicrobial activities of nisin, clausin, and amyloliquecidin, separately administered, were compared to that of a mupirocin-based ointment, which is commonly used as treatment forS. aureus-induced skin infections. Full-thickness excisional wounds, generated on the dorsal surfaces of mice, were infected with a bioluminescent strain ofS. aureus(strain Xen 36). The infections were monitored in real time usingin vivobioluminescent imaging. Lantibiotic treatments significantly reduced the bioluminescence ofS. aureusXen 36 to a level similar to that recorded with mupirocin treatment. Wound closure, however, was more pronounced during lantibiotic treatment. Lantibiotics thus have the potential to be used as an alternative treatment option forS. aureus-induced skin infections.
Draft Genome Sequence of
Megasphaera
sp. Strain DJF_B143, an Isolate from Pig Hindgut Unable to Produce Skatole
Authors: Li Xiaoqiong , Marshall Ian P. G. , Schreiber Lars , Højberg Ole , Canibe Nuria , Jensen Bent Borg
Published: April 2016

The butyrate-producing
Megasphaera
spp. predominate in the pig hindgut and may play important roles in gut health. Moreover, one
Megasphaera
isolate has been reported to produce the boar taint compound, skatole. Here, we provide a 2.58-Mbp draft genome of a pig hindgut isolate,
Megasphaera
sp. DJF_B143, unable to produce skatole.
Draft Genome Sequence of Olsenella scatoligenes SK9K4
T
, a Producer of 3-Methylindole (Skatole) and 4-Methylphenol (
p
-Cresol), Isolated from Pig Feces
Authors: Li Xiaoqiong , Højberg Ole , Noel Samantha Joan , Canibe Nuria , Jensen Bent Borg
Published: April 2016

Olsenella scatoligenes
SK9K4
T
is a strictly anaerobic bacterium isolated from pig feces that produces the malodorous compounds 3-methylindole (skatole) and 4-methylphenol (
p
-cresol). Here, we report the 2.47 Mbp draft genome sequence of SK9K4
T
, exploring pathways for the synthesis of skatole and
p
-cresol from the amino acids tryptophan and tyrosine, respectively.
Draft Genome Sequence of the Broad-Spectrum Xenobiotic Degrader
Achromobacter xylosoxidans
ADAF13
Authors: Iyer Rupa , Damania Ashish
Published: April 2016

Achromobacter xylosoxidans
ADAF13, isolated from farmland soil, possesses a large number of putative degradation genes and pathways that break down a wide variety of aromatic hydrocarbons, pesticides, endocrine disruptors, and other high-impact xenobiotics. These properties make this strain an excellent candidate for further development as a broad-spectrum bioremediation agent.
Complete Genome Sequence of
Salmonella enterica
Serovar Typhimurium Strain SO2 (Sequence Type 302) Isolated from an Asymptomatic Child in Mexico
Authors: Silva Claudia , Calva Edmundo , Puente José L. , Zaidi Mussaret B. , Vinuesa Pablo
Published: April 2016

The complete genome sequence of
Salmonella enterica
serovar Typhimurium strain SO2, isolated from an asymptomatic child in Mexico, was determined using PacBio single-molecule real-time technology. Strain SO2 has six complete chromosomal prophages, namely, ST104, Gifsy-2, ST64B, Gifsy-1, ELPhiS, and FSL SP-004, and carries a
Salmonella
virulence plasmid.
Complete Genome Sequence of
Mycoplasma mycoides
subsp.
mycoides
T1/44, a Vaccine Strain against Contagious Bovine Pleuropneumonia
Authors: Gourgues Géraldine , Barré Aurélien , Beaudoing Emmanuel , Weber Johann , Magdelenat Ghislaine , Barbe Valérie , Schieck Elise , Jores Joerg , Vashee Sanjay , Blanchard Alain , Lartigue Carole , Sirand-Pugnet Pascal
Published: April 2016

Mycoplasma mycoides
subsp.
mycoides
is the etiologic agent of contagious bovine pleuropneumonia. We report here the complete genome sequence of the strain T1/44, which is widely used as a live vaccine in Africa.
Genome Sequence of
Salegentibacter mishustinae
KCTC 12263, Containing a Complete Subtype I-B CRISPR-Cas System
Authors: Zhang Fei , Lin Wenxin , Zhang Rui , Zheng Qiang , Jiao Nianzhi
Published: April 2016

Salegentibacter mishustinae
KCTC strain 12263 was isolated from the sea urchin
Strongylocentrotus intermedius
inhabiting the Sea of Japan. Here, we report the draft genome sequence of
Salegentibacter mishustinae
KCTC 12263. It comprises ~3.78 Mb in 38 contigs with a G+C content of 36.5%, and a total of 3,490 proteins-coding genes were obtained. One complete CRISPR-Cas gene cluster was identified in the genome, which shows the strategy against invasive genetic elements of the strain.
Draft Genome Sequence of
Pseudomonas stutzeri
ODKF13, Isolated from Farmland Soil in Alvin, Texas
Authors: Iyer Rupa , Damania Ashish
Published: April 2016

Pseudomonas stutzeri
ODKF13 is a bacterial microorganism isolated from farmland soil in Alvin, Texas. This strain is notable for its naphthalene degradation and nitrogen fixation pathways and for its characterization as an organophosphate degrader of phosphotriester and phosphorothioate insecticides.
Draft Genome Sequence of Trueperella bernardiae LCDC 89-0504
T
, Isolated from a Human Blood Culture
Authors: Bernier Anne-Marie , Bernard Kathryn
Published: April 2016

We report here the draft genome sequence of
Trueperella bernardiae
LCDC 89-0504
T
, an organism linked to mild to severe infections in humans and animals. The genome size is 2,028,874 bp, with a G+C content of 65.44%. Annotation of the genome revealed 5 rRNA sequences, 48 tRNA genes, and 1,762 coding sequences.
Hyaluronan Modulation Impacts Staphylococcus aureus Biofilm Infection
Authors: Ibberson Carolyn B. , Parlet Corey P. , Kwiecinski Jakub , Crosby Heidi A. , Meyerholz David K. , Horswill Alexander R.
Published: April 2016

Staphylococcus aureus
is a leading cause of chronic biofilm infections. Hyaluronic acid (HA) is a large glycosaminoglycan abundant in mammalian tissues that has been shown to enhance biofilm formation in multiple Gram-positive pathogens. We observed that HA accumulated in an
S. aureus
biofilm infection using a murine implant-associated infection model and that HA levels increased in a mutant strain lacking hyaluronidase (HysA).
S. aureus
secretes HysA in order to cleave HA during infection. Through
in vitro
biofilm studies with HA, the
hysA
mutant was found to accumulate increased biofilm biomass compared to the wild type, and confocal microscopy showed that HA is incorporated into the biofilm matrix. Exogenous addition of purified HysA enzyme dispersed HA-containing biofilms, while catalytically inactive enzyme had no impact. Additionally, induction of
hysA
expression prevented biofilm formation and also dispersed an established biofilm in the presence of HA. These observations were corroborated in the implant model, where there was decreased dissemination from an
hysA
mutant biofilm infection compared to the
S. aureus
wild type. Histopathology demonstrated that infection with an
hysA
mutant caused significantly reduced distribution of tissue inflammation compared to wild-type infection. To extend these studies, the impact of HA and
S. aureus
HysA on biofilm-like aggregates found in joint infections was examined. We found that HA contributes to the formation of synovial fluid aggregates, and HysA can disrupt aggregate formation. Taken together, these studies demonstrate that HA is a relevant component of the
S. aureus
biofilm matrix and HysA is important for dissemination from a biofilm infection.
Type I Interferon Counters or Promotes Coxiella burnetii Replication Dependent on Tissue
Authors: Hedges Jodi F. , Robison Amanda , Kimmel Emily , Christensen Kelly , Lucas Erin , Ramstead Andrew , Jutila Mark A.
Published: April 2016

Coxiella burnetiiis an intracellular pathogen and the cause of Q fever. Gamma interferon (IFN-γ) is critical for host protection from infection, but a role for type I IFN inC. burnetiiinfection has not been determined. Type I IFN supports host protection from a related pathogen,Legionella pneumophila, and we hypothesized that it would be similarly protective inC. burnetiiinfection. In contrast to our prediction, IFN-α receptor-deficient (IFNAR−/−) mice were protected fromC. burnetii-induced infection. Therefore, the role of type I IFN inC. burnetiiinfection was distinct from that inL. pneumophila. Mice treated with a double-stranded-RNA mimetic were protected fromC. burnetii-induced weight loss through an IFNAR-independent pathway. We next treated mice with recombinant IFN-α (rIFN-α). When rIFN-α was injected by the intraperitoneal route during infection, disease-induced weight loss was exacerbated. Mice that received rIFN-α by this route had dampened interleukin 1β (IL-1β) expression in bronchoalveolar lavage fluids. However, when rIFN-α was delivered to the lung, bacterial replication was decreased in all tissues. Thus, the presence of type I IFN in the lung protected from infection, but when delivered to the periphery, type I IFN enhanced disease, potentially by dampening inflammatory cytokines. To better characterize the capacity for type I IFN induction byC. burnetii, we assessed expression of IFN-β transcripts by human macrophages following stimulation with lipopolysaccharide (LPS) fromC. burnetii. Understanding innate responses inC. burnetiiinfection will support the discovery of novel therapies that may be alternative or complementary to the current antibiotic treatment.
Antibiofilm Peptides: Potential as Broad-Spectrum Agents
Authors: Pletzer Daniel , Hancock Robert E. W.
Published: April 2016

The treatment of bacterial diseases is facing twin threats, with increasing bacterial antibiotic resistance and relatively few novel compounds or strategies under development or entering the clinic. Bacteria frequently grow on surfaces as biofilm communities encased in a polymeric matrix. The biofilm mode of growth is associated with 65 to 80% of all clinical infections. It causes broad adaptive changes; biofilm bacteria are especially (10- to 1,000-fold) resistant to conventional antibiotics and to date no antimicrobials have been developed specifically to treat biofilms. Small synthetic peptides with broad-spectrum antibiofilm activity represent a novel approach to treat biofilm-related infections. Recent developments have provided evidence that these peptides can inhibit even developed biofilms, kill multiple bacterial species in biofilms (including the ESKAPE [
Enterococcus faecium
,
Staphylococcus aureus
,
Klebsiella pneumoniae
,
Acinetobacter baumannii
,
Pseudomonas aeruginosa
, and
Enterobacter
species] pathogens), show strong synergy with several antibiotics, and act by targeting a universal stress response in bacteria. Thus, these peptides represent a promising alternative treatment to conventional antibiotics and work effectively in animal models of biofilm-associated infections.