bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human skeletal muscle fibre contractile properties and proteomic profile: adaptations to 3 weeks of unilateral lower limb suspension and active recovery
Authors: Brocca Lorenza , Longa Emanuela , Cannavino Jessica , Seynnes Olivier , de Vito Giuseppe , McPhee Jamie , Narici Marco , Pellegrino Maria Antonietta , Bottinelli Roberto 
Published: September 2015

Key points
It is generally assumed that muscle fibres go through atrophy following disuse with a loss of specific force and an increase in unloaded shortening velocity. However, the underlying mechanisms remain to be clarified.
Most studies have focused on events taking place during the development of disuse, whereas the subsequent recovery phase, which is equally important, has received little attention.
Our findings support the hypotheses that the specific force of muscle fibres decreased following unilateral lower limb suspension (ULLS) and returned to normal after 3 weeks of active recovery as a result of a loss and recovery of myosin and actin content.
Furthermore, muscle fibres went through extensive qualitative changes in muscle protein pattern following ULLS, and these were reversed by active recovery.
Resistance training was very effective in restoring both muscle mass and qualitative muscle changes, indicating that long‐term ULLS did not prevent the positive effect of exercise on human muscle.
AbstractFollowing disuse, muscle fibre function goes through adaptations such as a loss of specific force (PO/CSA) and an increase in unloaded shortening velocity, which could be a result of both quantitative changes (i.e. atrophy) and qualitative changes in protein pattern. The underlying mechanisms remain to be clarified. In addition, little is known about the recovery of muscle mass and strength following disuse. In the present study, we report an extensive dataset describing, in detail,the functional and protein content adaptations of skeletal muscle in response to both disuse and re‐training. Eight young healthy subjects were subjected to 3 weeks of unilateral lower limb suspension (ULLS), a widely used human model of disuse skeletal muscle atrophy. Needle biopsies samples were taken from the vastus lateralis muscle Pre‐ULLS, Post‐ULLS and after 3 weeks of recovery during which heavy resistance training was performed. After disuse, cross‐sectional area (CSA), PO/CSA and myosin concentration (MC) decreased in both type 1 and 2A skinned muscle fibres. After recovery, CSA and MC returned to levels comparable to those observed before disuse, whereas Po/CSA and unloaded shortening velocity reached a higher level. Myosin heavy chain isoform composition of muscle samples did not differ among the experimental groups. To study the mechanisms underlying such adaptations, a two‐dimensional proteomic analysis was performed. ULLS induced a reduction of myofibrillar, metabolic (glycolytic and oxidative) and anti‐oxidant defence system protein content. Resistance training was very effective in counteracting ULLS‐induced alterations, indicating that long‐term ULLS did not prevent the positive effect of exercise on human muscle.
In Vitro
Activities of Novel Antimicrobial Combinations against Extensively Drug-Resistant Acinetobacter baumannii
Authors: Córdoba J. , Coronado-Álvarez N. M. , Parra D. , Parra-Ruiz J. 
Published: September 2015

ABSTRACT

Extensively drug-resistant (XDR)
Acinetobacter
spp. have emerged as a cause of nosocomial infections, especially under conditions of intensive care. Unfortunately, resistance to colistin is increasing and there is a need for new therapeutic options. We aimed to study the effect of some novel combinations against XDR
Acinetobacter baumannii
in an
in vitro
pharmacokinetics-pharmacodynamics (PK/PD) model. Three nonrelated clinical strains of XDR
A. baumannii
were investigated. Antibiotic-simulated regimens were colistin at 3 MU every 8 h (q8h) (first dose, 6 MU), daptomycin at 10 mg/kg of body weight q24h, imipenem at 1 g q8h, and ertapenem at 1 g q24h. Combination regimens included colistin plus daptomycin, colistin plus imipenem, and imipenem plus ertapenem. Samples were obtained at 0, 1, 2, 4, 8, and 24 h. Among the single-agent regimens, only the colistin regimen resulted in significant reductions in log
10
CFU per milliliter compared to the control for all the strains tested. Although colistin achieved bactericidal activity at 4 h, it was not able to reach the limit of detection (1 log
10
CFU/ml). One strain had significant regrowth at 24 h without the emergence of resistance. Daptomycin-colistin combinations led to a significant reduction in levels of log
10
CFU per milliliter that were better than those achieved with colistin as a single-agent regimen, reaching the limit of detection at 24 h against all the strains. The combination of imipenem plus ertapenem outperformed the colistin regimen, although the results did not reach the limit of detection, with significant regrowth at 24 h. Similarly, colistin-plus-imipenem combinations reduced the levels of log
10
CFU per milliliter at 8 h, with significant regrowth at 24 h but with development of resistance to colistin. We have shown some potentially useful alternatives for the treatment of extensively drug-resistant
A. baumannii
. Among them, the daptomycin-colistin combination was the most effective and should be investigated in future studies.
Thymidine-Dependent Staphylococcus aureus Small-Colony Variants Are Induced by Trimethoprim-Sulfamethoxazole (SXT) and Have Increased Fitness during SXT Challenge
Authors: Kriegeskorte Andre , Lorè Nicola Ivan , Bragonzi Alessandra , Riva Camilla , Kelkenberg Marco , Becker Karsten , Proctor Richard A. , Peters Georg , Kahl Barbara C. 
Published: September 2015

ABSTRACT

Trimethoprim-sulfamethoxazole (SXT) is a possible alternative for the treatment of community- and hospital-acquired methicillin-resistant
Staphylococcus aureus
(MRSA) due to the susceptibility of most MRSA strains to the drug. However, after long-term treatment with SXT, thymidine-dependent (TD) SXT-resistant small-colony variants (SCVs) emerge. In TD-SCVs, mutations of thymidylate synthase ([TS]
thyA
) occur. Until now, it has never been systematically investigated that SXT is triggering the induction and/or selection of TD-SCVs. In our study, we performed induction, reversion, and competition experiments
in vitro
and
in vivo
using a chronic mouse pneumonia model to determine the impact of SXT on the emergence of TD-SCVs. SCVs were characterized by light and transmission electron microscopy (TEM) and auxotrophism testing. Short-term exposure of
S. aureus
to SXT induced the TD-SCV phenotype in
S. aureus
SH1000, while selection of TD-SCVs with
thyA
mutations occurred after long-term exposure. In reversion experiments with clinical and laboratory TD-SCVs, all revertants carried compensating mutations at the initially identified mutation site. Competition experiments
in vitro
and
in vivo
revealed a survival and growth advantage of the Δ
thyA
mutant under low-thymidine availability and SXT exposure although this advantage was less profound
in vivo
. Our results show that SXT induces the TD-SCV phenotype after short-term exposure, while long-term exposure selects for
thyA
mutations, which provide an advantage for TD-SCVs under specified conditions. Thus, our results further an understanding of the dynamic processes occurring during SXT exposure with induction and selection of
S. aureus
TD-SCVs.
Uncoupling Environmental pH and Intrabacterial Acidification from Pyrazinamide Susceptibility in Mycobacterium tuberculosis
Authors: Peterson Nicholas D. , Rosen Brandon C. , Dillon Nicholas A. , Baughn Anthony D. 
Published: September 2015

ABSTRACT

Pyrazinamide (PZA) is a first-line antitubercular drug for which the mode of action remains unresolved.
Mycobacterium tuberculosis
lacks measurable susceptibility to PZA under standard laboratory growth conditions. However, susceptibility to this drug can be induced by cultivation of the bacilli in an acidified growth medium. Previous reports suggested that the active form of PZA, pyrazinoic acid (POA), operates as a proton ionophore that confers cytoplasmic acidification when
M. tuberculosis
is exposed to an acidic environment. In this study, we demonstrate that overexpression of the PZA-activating enzyme PncA can confer PZA susceptibility to
M. tuberculosis
under neutral and even alkaline growth conditions. Furthermore, we find that wild-type
M. tuberculosis
displays increased susceptibility to POA relative to PZA in neutral and alkaline media. Utilizing a strain of
M. tuberculosis
that expresses a pH-sensitive green fluorescent protein (GFP), we find that unlike the bona fide ionophores monensin and carbonyl cyanide 3-chlorophenylhydrazone, PZA and POA do not induce rapid uncoupling or cytoplasmic acidification under conditions that promote susceptibility. Thus, based on these observations, we conclude that the antitubercular action of POA is independent of environmental pH and intrabacterial acidification.
Acinetobacter baumannii Extracellular OXA-58 Is Primarily and Selectively Released via Outer Membrane Vesicles after Sec-Dependent Periplasmic Translocation
Authors: Liao Yu-Ting , Kuo Shu-Chen , Chiang Ming-Hsien , Lee Yi-Tzu , Sung Wang-Chou , Chen You-Hsuan , Chen Te-Li , Fung Chang-Phone 
Published: September 2015

ABSTRACT

Carbapenem-resistant
Acinetobacter baumannii
(CRAb) shelter cohabiting carbapenem-susceptible bacteria from carbapenem killing via extracellular release of carbapenem-hydrolyzing class D β-lactamases, including OXA-58. However, the mechanism of the extracellular release of OXA-58 has not been elucidated.
In silico
analysis predicted OXA-58 to be translocated to the periplasm via the Sec system. Using cell fractionation and Western blotting, OXA-58 with the signal peptide and C terminus deleted was not detected in the periplasmic and extracellular fractions. Overexpression of enhanced green fluorescent protein fused to the OXA-58 signal peptide led to its periplasmic translocation but not extracellular release, suggesting that OXA-58 is selectively released. The majority of the extracellular OXA-58 was associated with outer membrane vesicles (OMVs). The OMV-associated OXA-58 was detected only in a strain overexpressing OXA-58. The presence of OXA-58 in OMVs was confirmed by a carbapenem inactivation bioassay, proteomic analysis, and transmission electron microscopy. Imipenem treatment increased OMV formation and caused cell lysis, resulting in an increase in the OMV-associated and OMV-independent release of extracellular OXA-58. OMV-independent OXA-58 hydrolyzed nitrocefin more rapidly than OMV-associated OXA-58 but was more susceptible to proteinase K degradation. Rose bengal, an SecA inhibitor, inhibited the periplasmic translocation and OMV-associated release of OXA-58 and abolished the sheltering effect of CRAb. This study demonstrated that the majority of the extracellular OXA-58 is selectively released via OMVs after Sec-dependent periplasmic translocation. Addition of imipenem increased both OMV-associated and OMV-independent OXA-58, which may have different biological roles. SecA inhibitor could abolish the carbapenem-sheltering effect of CRAb.
VT-1161 Protects Immunosuppressed Mice from Rhizopus arrhizus var. arrhizus Infection
Authors: Gebremariam Teclegiorgis , Wiederhold Nathan P. , Fothergill Annette W. , Garvey Edward P. , Hoekstra William J. , Schotzinger Robert J. , Patterson Thomas F. , Filler Scott G. , Ibrahim Ashraf S. 
Published: September 2015

ABSTRACT

We studied the efficacy of the investigational drug VT-1161 against mucormycosis. VT-1161 had more potent
in vitro
activity against
Rhizopus arrhizus
var.
arrhizus
than against
R. arrhizus
var.
delemar
. VT-1161 treatment demonstrated dose-dependent plasma drug levels with prolonged survival time and lowered tissue fungal burden in immunosuppressed mice infected with
R. arrhizus
var.
arrhizus
and was as effective as high-dose liposomal amphotericin B treatment. These results support further development of VT-1161 against mucormycosis.
Maternal Vaccination with a Fimbrial Tip Adhesin and Passive Protection of Neonatal Mice against Lethal Human Enterotoxigenic Escherichia coli Challenge
Authors: Luiz Wilson B. , Rodrigues Juliana F. , Crabb Joseph H. , Savarino Stephen J. , Ferreira Luis C. S. 
Published: September 2015

ABSTRACTGlobally, enterotoxigenicEscherichia coli(ETEC) is a leading cause of childhood and travelers' diarrhea, for which an effective vaccine is needed. Prevalent intestinal colonization factors (CFs) such as CFA/I fimbriae and heat-labile enterotoxin (LT) are important virulence factors and protective antigens. We tested the hypothesis that donor strand-complemented CfaE (dscCfaE), a stabilized form of the CFA/I fimbrial tip adhesin, is a protective antigen, using a lethal neonatal mouse ETEC challenge model and passive dam vaccination. For CFA/I-ETEC strain H10407, which has been extensively studied in volunteers, an inoculum of 2 × 107bacteria resulted in 50% lethal doses (LD50) in neonatal DBA/2 mice. Vaccination of female DBA/2 mice with CFA/I fimbriae or dscCfaE, each given with a genetically attenuated LT adjuvant (LTK63) by intranasal or orogastric delivery, induced high antigen-specific serum IgG and fecal IgA titers and detectable milk IgA responses. Neonates born to and suckled by dams antenatally vaccinated with each of these four regimens showed 78 to 93% survival after a 20× LD50challenge with H10407, compared to 100% mortality in pups from dams vaccinated with sham vaccine or LTK63 only. Crossover experiments showed that high pup survival rates after ETEC challenge were associated with suckling but not birthing from vaccinated dams, suggesting that vaccine-specific milk antibodies are protective. In corroboration, preincubation of the ETEC inoculum with antiadhesin and antifimbrial bovine colostral antibodies conferred a dose-dependent increase in pup survival after challenge. These findings indicate that the dscCfaE fimbrial tip adhesin serves as a protective passive vaccine antigen in this small animal model and merits further evaluation.
Pulmonary Immunostimulation with MALP-2 in Influenza Virus-Infected Mice Increases Survival after Pneumococcal Superinfection
Authors: Reppe Katrin , Radünzel Peter , Dietert Kristina , Tschernig Thomas , Wolff Thorsten , Hammerschmidt Sven , Gruber Achim D. , Suttorp Norbert , Witzenrath Martin 
Published: September 2015

ABSTRACTPulmonary infection with influenza virus is frequently complicated by bacterial superinfection, withStreptococcus pneumoniaebeing the most prevalent causal pathogen and hence often associated with high morbidity and mortality rates. Local immunosuppression due to pulmonary influenza virus infection has been identified as a major cause of the pathogenesis of secondary bacterial lung infection. Thus, specific local stimulation of the pulmonary innate immune system in subjects with influenza virus infection might improve the host defense against secondary bacterial pathogens. In the present study, we examined the effect of pulmonary immunostimulation with Toll-like receptor 2 (TLR-2)-stimulating macrophage-activating lipopeptide 2 (MALP-2) in influenza A virus (IAV)-infected mice on the course of subsequent pneumococcal superinfection. Female C57BL/6N mice infected with IAV were treated with MALP-2 on day 5 and challenged withS. pneumoniaeon day 6. Intratracheal MALP-2 application increased proinflammatory cytokine and chemokine release and enhanced the recruitment of leukocytes, mainly neutrophils, into the alveolar space of IAV-infected mice, without detectable systemic side effects. Local pulmonary instillation of MALP-2 in IAV-infected mice 24 h before transnasal pneumococcal infection considerably reduced the bacterial number in the lung tissue without inducing exaggerated inflammation. The pulmonary viral load was not altered by MALP-2. Clinically, MALP-2 treatment of IAV-infected mice increased survival rates and reduced hypothermia and body weight loss after pneumococcal superinfection compared to those of untreated coinfected mice. In conclusion, local immunostimulation with MALP-2 in influenza virus-infected mice improved pulmonary bacterial elimination and increased survival after subsequent pneumococcal superinfection.
Interleukin-10 Modulates Antigen Presentation by Dendritic Cells through Regulation of NLRP3 Inflammasome Assembly during Chlamydia Infection
Authors: Omosun Yusuf , McKeithen Danielle , Ryans Khamia , Kibakaya Caroline , Blas-Machado Uriel , Li Duo , Singh Rajesh , Inoue Koichi , Xiong Zhi-Gang , Eko Francis , Black Carolyn , Igietseme Joseph , He Qing 
Published: September 2015

ABSTRACTInterleukin-10 (IL-10) has been implicated in susceptibility to genital chlamydial infection and the development of tubal pathologies. IL-10 limitation also resulted in the rapid elicitation of immune responses againstChlamydia, and decreased levels of IL-10 correlated with protective anti-Chlamydiaimmunity. To investigate the molecular basis for these effects, we compared the reproductive pathologies and fertility rates inChlamydia-infected wild-type (WT) and IL-10-knockout (IL-10−/−) mice; we also analyzed the expression of the Toll-like receptor (TLR)/interleukin-1 receptor (IL-1R) superfamily, IL-1β production, NLRP3 inflammasome assembly and activation, and the immunostimulatory capacity and apoptotic predilection ofChlamydia-exposed dendritic cells (DCs) from WT and IL-10−/−mice. Our results revealed that, in addition to the rapid clearance of infection, genitally infected IL-10−/−mice were protected from tubal pathologies and infertility, whereas WT (IL-10+/+) mice were not.Chlamydia-pulsed IL-10−/−DCs expressed larger numbers of TLR4/IL-1R molecules and had enhanced IL-1β production. In addition, NLRP3 inflammasome assembly was suppressed in IL-10−/−DCs through the inhibition of the P2X purinoceptor 7 (P2X7) receptor (P2X7R), an ATP-gated ion channel, and a decrease in intracellular Ca2+levels, which inhibited DC apoptosis. Thus, the potent immunostimulatory capacity of IL-10-deficient DCs is due, at least in part, to the suppression of the intracellular inflammasome assembly, which prevents DC apoptosis, allowing efficient antigen presentation. The results indicate that IL-10 deficiency enables efficient antigen presentation by DCs for rapid and enhanced immune activation againstChlamydia, which results in rapid microbial clearance, which prevents tubal pathologies during infection. Our finding has important implications for the induction of protective immunity againstChlamydiaand other infectious and noninfectious diseases by vaccines.
‘It doesn't do the care for you': a qualitative study of health care professionals' perceptions of the benefits and harms of integrated care pathways for end of life care
Authors: Sleeman Katherine E , Koffman Jonathan , Bristowe Katherine , Rumble Caroline , Burman Rachel , Leonard Sara , Noble Jo , Dampier Odette , Bernal William , Morgan Myfanwy , Hopkins Philip , Prentice Wendy , Higginson Irene J 
Published: September 2015

ObjectivesTo understand healthcare professionals’ perceptions of the benefits and potential harms of integrated care pathways for end-of-life care, to inform the development of future interventions that aim to improve care of the dying.DesignQualitative interview study with maximum variation sampling and thematic analysis.Participants25 healthcare professionals, including doctors, nurses and allied health professionals, interviewed in 2009.SettingA 950-bed South London teaching hospital.Results4 main themes emerged, each including 2 subthemes. Participants were divided between (1) those who described mainly the benefits of integrated care pathways, and (2) those who talked about potential harms. Benefits focused on processes of care, for example, clearer, consistent and comprehensive actions. The recipients of these benefits were staff members themselves, particularly juniors. For others, this perceived clarity was interpreted as of potential harm to patients, where over-reliance on paperwork lead to prescriptive, less thoughtful care, and an absolution from decision-making. Independent of their effects on patient care, integrated care pathways for dying had (3) a symbolic value: they legitimised death as a potential outcome and were used as a signal that the focus of care had changed. However, (4) a weak infrastructure, including scanty education and training in end-of-life care and a poor evidence base, that appeared to undermine the foundations on which the Liverpool Care Pathway was built.ConclusionsThe potential harms of integrated care pathways for the dying identified in this study were reminiscent of criticisms subsequently published by the Neuberger review. These data highlight: (1) the importance of collecting, reporting and using qualitative data when developing and evaluating complex interventions; (2) that comprehensive education and training in palliative care is critical for the success of any new intervention; (3) the need for future interventions to be grounded in patient-centred outcomes, not just processes of care.
Clinical efficacy and mechanistic evaluation of aflibercept for proliferative diabetic retinopathy (acronym CLARITY): a multicentre phase IIb randomised active-controlled clinical trial
Authors: Sivaprasad Sobha , Prevost A Toby , Bainbridge James , Edwards Rhiannon Tudor , Hopkins David , Kelly Joanna , Luthert Phil , Murphy Caroline , Ramu Jayashree , Sarafraz-Shekary Negin , Vasconcelos Joana , White-Alao Beverley , Hykin Philip 
Published: September 2015

IntroductionProliferative diabetic retinopathy (PDR) is the main cause of severe visual loss in people with diabetes mellitus. The standard treatment for this condition is panretinal photocoagulation (PRP). This laser treatment is inherently destructive, with predictable adverse effects on visual function, and a safer alternative is required. Intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors can induce short-term regression of retinal neovascularisation. The aim of this randomised controlled trial is to determine the efficacy, safety and cost-effectiveness of intravitreal aflibercept, an inhibitor of VEGF-A, VEGF-B and placental growth factor (PLGF), in PDR, and to investigate the impact on local oxygenation.Methods and analysisThis is a phase IIb randomised controlled single-masked multicentre clinical trial to determine the impact of repeated intravitreal aflibercept injections in the treatment and prevention of PDR. 220 participants with treatment-naïve or treated but active retinal neovascularisation in at least one eye will be randomly allocated 1:1 to intravitreal aflibercept injections or PRP for a period of 52 weeks. The primary outcome is the change in best-corrected visual acuity in the study eye at 52 weeks. Secondary outcomes include changes from baseline in other visual functions, anatomical changes and cost-effectiveness. Ocular and non-ocular adverse events will also be reported over 52 weeks.Ethics and disseminationThe study has been approved by the National Research Ethics Service (NRES) committee with respect to scientific content and compliance with applicable research and human subjects’ regulations. Findings will be reported through scientific publications and research conferences. The results of this study will provide clinical evidence for the feasibility, efficacy safety and cost-effectiveness of intravitreal aflibercept for PDR.Trial registration numberISRCTN 32207582.