bluuebunny/crossref_metadata_2025_split huggingface dataset:
Overload‐induced skeletal muscle extracellular matrix remodelling and myofibre growth in mice lacking IL‐6
Authors: White J. P. , Reecy J. M. , Washington T. A. , Sato S. , Le M. E. , Davis J. M. , Wilson L. B. , Carson J. A. 
Published: August 2009

AbstractAim:  Overloading healthy skeletal muscle produces myofibre hypertrophy and extracellular matrix remodelling, and these processes are thought to be interdependent for producing muscle growth. Inflammatory cytokine interleukin‐6 (IL‐6) gene expression is induced in overloaded skeletal muscle, and the loss of this IL‐6 induction can attenuate the hypertrophic response to overload (OV). Although the OV induction of IL‐6 in skeletal muscle may be an important regulator of inflammatory processes and satellite cell proliferation, less is known about its role in the regulation of extracellular matrix remodelling. The purpose of the current study was to examine if OV‐induced extracellular matrix remodelling, muscle growth, and associated gene expression were altered in mice that lack IL‐6, when compared with wild‐type mice.Methods:  Male C57/BL6 (WT) and C57/BL6 × IL‐6−/− (IL‐6−/−) mice (10 weeks of age) were assigned to either a sham control or synergist ablation OV treatments for 3, 21 or 56 days.Result:  Plantaris muscle mass increased 59% in WT and 116% in IL‐6−/− mice after 21 day OV. Myofibre CSA was also increased by 21 day OV in both WT and IL‐6−/− mice. OV induced a twofold greater increase in the volume of non‐contractile tissue in IL‐6−/− muscle compared to WT. OV also induced a significantly greater accumulation of hydroxyproline and procollagen‐1 mRNA in IL‐6−/− muscle, when compared with WT muscle after 21 day OV. Transforming growth factor‐β and insulin‐like growth factor‐1 mRNA expression were also induced to a greater extent in IL‐6−/− muscle when compared with WT muscle after 21 day OV. There was no effect of IL‐6 loss on the induction of myogenin, and cyclin D1 mRNA expression after 3 day OV. However, MyoD mRNA expression in 3 day OV IL‐6−/− muscle was attenuated when compared with WT OV mice.Conclusion:  IL‐6 appears to be necessary for the normal regulation of extracellular matrix remodelling during OV‐induced growth.
Risk factors for feline hyperthyroidism in the UK
Authors: Wakeling J. , Everard A. , Brodbelt D. , Elliott J. , Syme H. 
Published: August 2009

Objectives:Previous studies of cats in the USA and New Zealand have identified a number of risk factors for the development of hyperthyroidism including feeding of canned cat food and being non‐purebred. The objective of this study was to examine these and other risk factors in cats from London, UK.Methods:A questionnaire‐based case‐control study of hyperthyroidism in cats greater than eight years of age was undertaken. Cases and controls were recruited from two groups of first opinion clinics in London, UK (five locations in total). The two‐page questionnaire investigated details of lifestyle, diet and exposure to environmental chemicals. Data analysis included multivariable analysis of risk factors using binary logistic regression.Results:One hundred and nine hyperthyroid cats and 196 control cats were surveyed. Increasing age, non‐pure breed, use of a litter box, more than 50 per cent wet food in the diet, a diet that included fish and exposure to food in a can were identified as risk factors for the development of hyperthyroidism using multivariable analysis.ClinicalSignificance:Risk factors for hyperthyroidism in cats from the UK appear similar to those of other countries. Exposure to food packaged in a can was identified as the major risk factor for the development of hyperthyroidism.
Identification of direct transcriptional targets of V600EBRAF/MEK signalling in melanoma
Authors: Packer Leisl M , East Philip , Reis‐Filho Jorge S , Marais Richard 
Published: August 2009

SummaryOncogenic mutations in BRAF are common in melanoma and drive constitutive activation of the MEK/ERK pathway. To elucidate the transcriptional events downstream of V600EBRAF/MEK signalling we performed gene expression profiling of A375 melanoma cells treated with potent and selective inhibitors of V600EBRAF and MEK (PLX4720 and PD184352 respectively). Using a stringent Bayesian approach, we identified 69 transcripts that appear to be direct transcriptional targets of this pathway and whose expression changed after 6 h of pathway inhibition. We also identified several additional genes whose expression changed after 24 h of pathway inhibition and which are likely to be indirect transcriptional targets of the pathway. Several of these were confirmed by demonstrating their expression to be similarly regulated when BRAF was depleted using RNA interference, and by using qRT‐PCR in other BRAF mutated melanoma lines. Many of these genes are transcription factors and feedback inhibitors of the ERK pathway and are also regulated by MEK signalling in NRAS mutant cells. This study provides a basis for understanding the molecular processes that are regulated by V600EBRAF/MEK signalling in melanoma cells.
Aryl Rhodanines Specifically Inhibit Staphylococcal and Enterococcal Biofilm Formation
Authors: Opperman Timothy J. , Kwasny Steven M. , Williams John D. , Khan Atiyya R. , Peet Norton P. , Moir Donald T. , Bowlin Terry L. 
Published: August 2009

ABSTRACT

Staphylococcus epidermidis
and
Staphylococcus aureus
are the leading causative agents of indwelling medical device infections because of their ability to form biofilms on artificial surfaces. Here we describe the antibiofilm activity of a class of small molecules, the aryl rhodanines, which specifically inhibit biofilm formation of
S. aureus
,
S. epidermidis
,
Enterococcus faecalis
,
E. faecium
, and
E. gallinarum
but not the gram-negative species
Pseudomonas aeruginosa
or
Escherichia coli
. The aryl rhodanines do not exhibit antibacterial activity against any of the bacterial strains tested and are not cytotoxic against HeLa cells. Preliminary mechanism-of-action studies revealed that the aryl rhodanines specifically inhibit the early stages of biofilm development by preventing attachment of the bacteria to surfaces.
Antimicrobial Activities of Piperacillin-Tazobactam against
Haemophilus influenzae
Isolates, Including β-Lactamase-Negative Ampicillin-Resistant and β-Lactamase-Positive Amoxicillin- Clavulanate-Resistant Isolates, and Mutations in Their Quinolone Resistance-Determining Regions
Authors: Hirakata Yoichi , Ohmori Kaori , Mikuriya Miwako , Saika Takeshi , Matsuzaki Kaoru , Hasegawa Miyuki , Hatta Masumitsu , Yamamoto Natsuo , Kunishima Hiroyuki , Yano Hisakazu , Kitagawa Miho , Arai Kazuaki , Kawakami Kazuyoshi , Kobayashi Intetsu , Jones Ronald N. , Kohno Shigeru , Yamaguchi Keizo , Kaku Mitsuo 
Published: August 2009

ABSTRACT

β-Lactamase-negative ampicillin-resistant (BLNAR) isolates of
Haemophilus influenza
e
have been emerging in some countries, including Japan. The Clinical and Laboratory Standards Institute has only a susceptible MIC breakpoint (≤1 μg/ml) for piperacillin-tazobactam and a disclaimer comment that BLNAR
H. influenzae
should be considered resistant, which was adapted without presentation of data. In addition, fluoroquinolone-resistant
H. influenzae
isolates have recently been occasionally reported worldwide. To address these problems, we examined susceptibilities to β-lactams, including piperacillin-tazobactam, and ciprofloxacin by microdilution and disk diffusion (only for piperacillin-tazobactam) methods, against a total of 400 recent
H. influenzae
clinical isolates, including 100 β-lactamase-negative ampicillin-susceptible, β-lactamase-positive ampicillin-resistant, BLNAR, and β-lactamase-positive amoxicillin-clavulanate-resistant (BLPACR) isolates each. BLNAR and BLPACR isolates were tested by PCR using primers that amplify specific regions of the
ftsI
gene. We also detected mutations in quinolone resistance-determining regions (QRDRs) by direct sequencing of the PCR products of DNA fragments. Among β-lactams, piperacillin-tazobactam exhibited potent activity against all isolates of
H. influenzae
, with all MICs at ≤0.5 μg/ml (susceptible). A disk diffusion breakpoint for piperacillin-tazobactam of ≥21 mm is proposed. We confirmed that all BLNAR and BLPACR isolates had amino acid substitutions in the
ftsI
gene and that the major pattern was group III-like (87.5%). One ciprofloxacin-resistant isolate (MIC, 16 μg/ml) and 31 ciprofloxacin-susceptible isolates (MICs, 0.06 to 0.5 μg/ml) had amino acid changes in their QRDRs. Piperacillin-tazobactam was the most potent β-lactam tested against all classes of
H. influenzae
isolates. It is possible that fluoroquinolone-resistant
H. influenzae
will emerge since several clinical isolates carried mutations in their QRDRs.
In Vitro Generation of Neuraminidase Inhibitor Resistance in A(H5N1) Influenza Viruses
Authors: Hurt Aeron C. , Holien Jessica K. , Barr Ian G. 
Published: August 2009

ABSTRACTTo identify mutations that can arise in highly pathogenic A(H5N1) viruses under neuraminidase inhibitor selective pressure, two antigenically different strains were serially passaged with increasing levels of either oseltamivir or zanamivir. Under oseltamivir pressure, both A(H5N1) viruses developed a H274Y neuraminidase mutation, although in one strain the mutation occurred in combination with an I222M neuraminidase mutation. The H274Y neuraminidase mutation reduced oseltamivir susceptibility significantly (900- to 2,500-fold compared to the wild type). However the dual H274Y/I222M neuraminidase mutation had an even greater impact on resistance, with oseltamivir susceptibility reduced significantly further (8,000-fold compared to the wild type). A similar affect on oseltamivir susceptibility was observed when the dual H274Y/I222M mutations were introduced, by reverse genetics, into a recombinant seasonal human A(H1N1) virus and also when an alternative I222 substitution (I222V) was generated in combination with H274Y in A(H5N1) and A(H1N1) viruses. These viruses remained fully susceptible to zanamivir but demonstrated reduced susceptibility to peramivir. Following passage of the A(H5N1) viruses in the presence of zanamivir, the strains developed a D198G neuraminidase mutation, which reduced susceptibility to both zanamivir and oseltamivir, and also an E119G neuraminidase mutation, which demonstrated significantly reduced zanamivir susceptibility (1,400-fold compared to the wild type). Mutations in hemagglutinin residues implicated in receptor binding were also detected in many of the resistant strains. This study identified the mutations that can arise in A(H5N1) under either oseltamivir or zanamivir selective pressure and the potential for dual neuraminidase mutations to result in dramatically reduced drug susceptibility.
Natural Polymorphisms of Human Immunodeficiency Virus Type 1 Integrase and Inherent Susceptibilities to a Panel of Integrase Inhibitors
Authors: Low Andrea , Prada Nicole , Topper Michael , Vaida Florin , Castor Delivette , Mohri Hiroshi , Hazuda Daria , Muesing Mark , Markowitz Martin 
Published: August 2009

ABSTRACTWe evaluated the human immunodeficiency virus type 1 (HIV-1) integrase coding region of thepolgene for the presence of natural polymorphisms in patients during early infection (AHI) and with triple-class drug-resistant HIV-1 (MDR). We analyzed selected recombinant viruses containing patient-derived HIV-1 integrase for susceptibility to a panel of strand transfer integrase inhibitors (InSTI). A pretreatment sequence analysis of the integrase coding region was performed for 112 patients identified during acute or early infection and 15 patients with triple-class resistance. A phenotypic analysis was done on 10 recombinant viruses derived from nine patients against a panel of six diverse InSTI. Few of the polymorphisms associated with in vitro InSTI resistance were identified in the samples from newly infected individuals or those patients with MDR HIV-1. We identified polymorphisms V72I, L74I, T97A, V151I, M154I/L, E157Q, V165I, V201I, I203M, T206S, and S230N. V72I was the most common, seen in 63 (56.3%) of the AHI samples. E157Q was the only naturally occurring mutation thought to contribute to resistance to elvitegravir, raltegravir, and L-870,810. None of the patient-derived viruses demonstrated any significant decrease in susceptibility to the drugs tested. In summary, the integrase coding region contains as much natural variation as that seen in protease, but mutations associated with high-level resistance to existing InSTI are rarely, if ever, present in integrase naïve patients, especially those being used clinically. Most of the highly prevalent polymorphisms have little effect on InSTI susceptibility in the absence of specific primary mutations. Baseline testing for integrase susceptibility in InSTI-naïve patients is not currently warranted.
IND-6, a Highly Divergent IND-Type Metallo-β-Lactamase fromChryseobacterium indologenesStrain 597 Isolated in Burkina Faso
Authors: Zeba Boukaré , De Luca Filomena , Dubus Alain , Delmarcelle Michael , Simporé Jacques , Nacoulma Odile G. , Rossolini Gian Maria , Frère Jean-Marie , Docquier Jean-Denis 
Published: August 2009

ABSTRACTThe genusChryseobacteriumand other genera belonging to the familyFlavobacteriaceaeinclude organisms that can behave as human pathogens and are known to cause different kinds of infections. Several species ofFlavobacteriaceae, includingChryseobacterium indologenes, are naturally resistant to β-lactam antibiotics (including carbapenems), due to the production of a resident metallo-β-lactamase. AlthoughC. indologenespresently constitutes a limited clinical threat, the incidence of infections caused by this organism is increasing in some settings, where isolates that exhibit multidrug resistance phenotypes (including resistance to aminoglycosides and quinolones) have been detected. Here, we report the identification and characterization of a new IND-type variant from aC. indologenesisolate from Burkina Faso that is resistant to β-lactams and aminoglycosides. The levels of sequence identity of the new variant to other IND-type metallo-β-lactamases range between 72 and 90% (for IND-4 and IND-5, respectively). The purified enzyme exhibited N-terminal heterogeneity and a posttranslational modification consisting of the presence of a pyroglutamate residue at the N terminus. IND-6 shows a broad substrate profile, with overall higher turnover rates than IND-5 and higher activities than IND-2 and IND-5 against ceftazidime and cefepime.
Mycobacterium tuberculosisCell Wall Glycolipids Directly Inhibit CD4+T-Cell Activation by Interfering with Proximal T-Cell-Receptor Signaling
Authors: Mahon Robert N. , Rojas Roxana E. , Fulton Scott A. , Franko Jennifer L. , Harding Clifford V. , Boom W. Henry 
Published: August 2009

ABSTRACTImmune evasion is required forMycobacterium tuberculosisto survive in the face of robust adaptive CD4+T-cell responses. We have previously shown thatM. tuberculosiscan indirectly inhibit CD4+T cells by suppressing the major histocompatibility complex class II antigen-presenting cell function of macrophages. This study was undertaken to determine ifM. tuberculosiscould directly inhibit CD4+T-cell activation. Murine CD4+T cells were purified from spleens by negative immunoaffinity selection followed by flow sorting. Purified CD4+T cells were activated for 16 to 48 h with CD3 and CD28 monoclonal antibodies in the presence or absence ofM. tuberculosisand its subcellular fractions. CD4+T-cell activation was measured by interleukin 2 production, proliferation, and expression of activation markers, all of which were decreased in the presence ofM. tuberculosis. Fractionation identified thatM. tuberculosiscell wall glycolipids, specifically, phosphatidylinositol mannoside and mannose-capped lipoarabinomannan, were potent inhibitors. Glycolipid-mediated inhibition was not dependent on Toll-like receptor signaling and could be bypassed through stimulation with phorbol 12-myristate 13-acetate and ionomycin. ZAP-70 phosphorylation was decreased in the presence ofM. tuberculosisglycolipids, indicating thatM. tuberculosisglycolipids directly inhibited CD4+T-cell activation by interfering with proximal T-cell-receptor signaling.
Antibody Protection against Botulinum Neurotoxin Intoxication in Mice
Authors: Cheng Luisa W. , Stanker Larry H. , Henderson Thomas D. , Lou Jianlong , Marks James D. 
Published: August 2009

ABSTRACT
Adulteration of food or feed with any of the seven serotypes of botulinum neurotoxin (BoNT) is a potential bioterrorism concern. Currently, there is strong interest in the development of detection reagents, vaccines, therapeutics, and other countermeasures. A sensitive immunoassay for detecting BoNT serotype A (BoNT/A), based on monoclonal antibodies (MAbs) F1-2 and F1-40, has been developed and used in complex matrices. The epitope for F1-2 has been mapped to the heavy chain of BoNT/A, and the epitope of F1-40 has been mapped to the light chain. The ability of these MAbs to provide therapeutic protection against BoNT/A intoxication in mouse intravenous and oral intoxication models was tested. High dosages of individual MAbs protected mice well both pre- and postexposure to BoNT/A holotoxin. A combination therapy consisting of antibodies against both the light and heavy chains of the toxin, however, significantly increased protection, even at a lower MAb dosage. An in vitro peptide assay for measuring toxin activity showed that pretreatment of toxin with these MAbs did not block catalytic activity but instead blocked toxin entry into primary and cultured neuronal cells. The timing of antibody rescue in the mouse intoxication models revealed windows of opportunity for antibody therapeutic treatment that correlated well with the biologic half-life of the toxin in the serum. Knowledge of BoNT intoxication and antibody clearance in these mouse models and understanding of the pharmacokinetics of BoNT are invaluable for future development of antibodies and therapeutics against intoxication by BoNT.
Perforin and Gamma Interferon Expression Are Required for CD4+and CD8+T-Cell-Dependent Protective Immunity against a Human Parasite,Trypanosoma cruzi, Elicited by Heterologous Plasmid DNA Prime-Recombinant Adenovirus 5 Boost Vaccination
Authors: de Alencar Bruna C. G. , Persechini Pedro M. , Haolla Filipe A. , de Oliveira Gabriel , Silverio Jaline C. , Lannes-Vieira Joseli , Machado Alexandre V. , Gazzinelli Ricardo T. , Bruna-Romero Oscar , Rodrigues Mauricio M. 
Published: August 2009

ABSTRACTA heterologous prime-boost strategy using plasmid DNA, followed by replication-defective recombinant adenovirus 5, is being proposed as a powerful way to elicit CD4+and CD8+T-cell-mediated protective immunity against intracellular pathogens. We confirmed this concept and furthered existing research by providing evidence that the heterologous prime-boost regimen using the gene encoding amastigote surface protein 2 elicited CD4+and CD8+T-cell-mediated protective immunity (reduction of acute parasitemia and prolonged survival) against experimental infection withTrypanosoma cruzi. Protective immunity correlated with the presence of in vivo antigen-specific cytotoxic activity prior to challenge. Based on this, our second goal was to determine the outcome of infection after heterologous prime-boost immunization of perforin-deficient mice. These mice were highly susceptible to infection. A detailed analysis of the cell-mediated immune responses in immunized perforin-deficient mice showed an impaired gamma interferon (IFN-γ) secretion by immune spleen cells upon restimulation in vitro with soluble recombinant antigen. In spite of a normal numeric expansion, specific CD8+T cells presented several functional defects detected in vivo (cytotoxicity) and in vitro (simultaneous expression of CD107a/IFN-γ or IFN-γ/tumor necrosis factor alpha) paralleled by a decreased expression of CD44 and KLRG-1. Our final goal was to determine the importance of IFN-γ in the presence of highly cytotoxic T cells. Vaccinated IFN-γ-deficient mice developed highly cytotoxic cells but failed to develop any protective immunity. Our study thus demonstrated a role for perforin and IFN-γ in a number of T-cell-mediated effector functions and in the antiparasitic immunity generated by a heterologous plasmid DNA prime-adenovirus boost vaccination strategy.
Biochemical and pharmacokinetic characterisation of two PEGylated variants of dipetarudin
Authors: Koehler Anne , Nowak Goetz , López Mercedes 
Published: August 2009

SummaryDipetarudin was coupled to polyethylene glycol (PEG)-5000 residues in order to improve its pharmacokinetic profile and to enhance its anticoagulant efficacy. The resulting compounds, mono-and di-PEGylated dipetarudin were purified by gel filtration. Mono-PEGylated dipetarudin exhibited similar activity like its non-conjugated equivalent both in vitro and in vivo. However, di-PEGylated dipetarudin showed longer distribution and elimination half-lives and higher area under the time-concentration curve in comparison with the unmodified inhibitor which may be attributed to decreased renal clearance. Futhermore, ratio k
12/k
21 decreased when the number of PEG chains coupled to dipetarudin increased. It means that the intercompartment transfer of dipetarudin, characterised by a fast distribution and a high retention in the peripheral compartment, is reverted by coupling to PEG. Thus, the transfer of mono-PEGylated dipetarudin between these compartments is similar in both senses and the transfer of di-PEGylated dipetarudin is slower from vascular to extravascular compartment than vice versa. Our results show that di-PEGylated dipetarudin produces a better and longer anticoagulant effect than unmodified dipetarudin which is a desirable attribute for future therapeutic application.
The effects of hyperglycaemia on thrombin-activatable fibrinolysis inhibitor
Authors: Verkleij Chantal J. N. , Nieuwdorp Max , Gerdes Victor E. A. , Mörgelin Matthias , Meijers Joost C. M. , Marx Pauline F. 
Published: August 2009

SummaryEpidemiological studies have shown a strong association between type 2 diabetes mellitus and cardiovascular diseases, and hypofibrinolysis may contribute to this phenomenon. The aim of this study was to determine the effect of hyperglycaemia on thrombin-activatable fibrinolysis inhibitor (TAFI). Hyperglycaemia was mimicked in vitro by incubation of TAFI with glyceraldehyde and in vivo by hyperglycaemic clamping of healthy volunteers. The effects of long-term hyperglycaemia in vivo on TAFI were investigated by comparing TAFI from poorly regulated and tightly regulated patients with type 2 diabetes. In vitro glycated TAFI showed an altered migration pattern on SDS-PAGE due to aggregation. Glycated TAFI showed decreased activity after activation by thrombin-thrombomodulin in a glyceraldehyde-dosedependent manner and a reduced anti-fibrinolytic potential. In vivo, no differences in TAFI parameters were found after hyper-glycaemic clamping of healthy volunteers and between tightly and poorly regulated patients with type 2 diabetes. Moreover, TAFI purified from poorly regulated and tightly regulated patients with type 2 diabetes migrated similarly on SDS-PAGE, indicating little or no glycation of the protein. Despite the deleterious effects of glycation of TAFI in vitro on its function, TAFI was neither affected by hyperglycaemic clamping, nor by long-term hyperglycaemia in patients with type 2 diabetes. This is in contrast to fibrinolytic factors as plasminogen-activator inhibitor I and tissue-type plasminogen activator, which are affected. We therefore hypothesise that a normally functioning TAFI under hyperglycaemic conditions may tip the haemostatic balance towards hypofibrinolysis, which may contribute to the development of cardiovascular diseases in type 2 diabetic patients.