bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enterococcus faecalis Gelatinase Mediates Intestinal Permeability via Protease-Activated Receptor 2
Authors: Maharshak Nitsan , Huh Eun Young , Paiboonrungruang Chorlada , Shanahan Michael , Thurlow Lance , Herzog Jeremy , Djukic Zorka , Orlando Roy , Pawlinski Rafal , Ellermann Melissa , Borst Luke , Patel Siten , Dotan Iris , Sartor Ryan B. , Carroll Ian M. 
Published: April 2015

ABSTRACT

Microbial protease-mediated disruption of the intestinal epithelium is a potential mechanism whereby a dysbiotic enteric microbiota can lead to disease. This mechanism was investigated using the colitogenic, protease-secreting enteric microbe
Enterococcus faecalis
. Caco-2 and T-84 epithelial cell monolayers and the mouse colonic epithelium were exposed to concentrated conditioned media (CCM) from
E. faecalis
V583 and
E. faecalis
lacking the gelatinase gene (
gelE
). The flux of fluorescein isothiocyanate (FITC)-labeled dextran across monolayers or the mouse epithelium following exposure to CCM from parental or mutant
E. faecalis
strains indicated paracellular permeability. A protease-activated receptor 2 (PAR2) antagonist and PAR2-deficient (PAR2
−/−
) mice were used to investigate the role of this receptor in
E. faecalis
-induced permeability. Gelatinase (GelE) purified from
E. faecalis
V583 was used to confirm the ability of this protease to induce epithelial cell permeability and activate PAR2. The protease-mediated permeability of colonic epithelia from wild-type (WT) and PAR2
−/−
mice by fecal supernatants from ulcerative colitis patients was assessed. Secreted
E. faecalis
proteins induced permeability in epithelial cell monolayers, which was reduced in the absence of
gelE
or by blocking PAR2 activity. Secreted
E. faecalis
proteins induced permeability in the colonic epithelia of WT mice that was absent in tissues from PAR2
−/−
mice. Purified GelE confirmed the ability of this protease to induce epithelial cell permeability via PAR2 activation. Fecal supernatants from ulcerative colitis patients induced permeability in the colonic epithelia of WT mice that was reduced in tissues from PAR2
−/−
mice. Our investigations demonstrate that GelE from
E. faecalis
can regulate enteric epithelial permeability via PAR2.
Overexpression of Porcine Beta-Defensin 2 Enhances Resistance to Actinobacillus pleuropneumoniae Infection in Pigs
Authors: Yang Xi , Cheng Yu-Ting , Tan Mei-Fang , Zhang Hua-Wei , Liu Wan-Quan , Zou Geng , Zhang Liang-Sheng , Zhang Chun-Yan , Deng Si-Min , Yu Lei , Hu Xue-Ying , Li Lu , Zhou Rui 
Published: April 2015

ABSTRACT

To reduce the need for antibiotics in animal production, alternative approaches are needed to control infection. We hypothesized that overexpression of native defensin genes will provide food animals with enhanced resistance to bacterial infections. In this study, recombinant porcine beta-defensin 2 (PBD-2) was overexpressed in stably transfected PK-15 porcine kidney cells. PBD-2 antibacterial activities against
Actinobacillus pleuropneumoniae
, an important respiratory pathogen causing porcine contagious pleuropneumonia, were evaluated on agar plates. Transgenic pigs constitutively overexpressing PBD-2 were produced by a somatic cell cloning method, and their resistance to bacterial infection was evaluated by direct or cohabitation infection with
A. pleuropneumoniae
. Recombinant PBD-2 peptide that was overexpressed in the PK-15 cells showed antibacterial activity against
A. pleuropneumoniae
. PBD-2 was overexpressed in the heart, liver, spleen, lungs, kidneys, and jejunum of the transgenic pigs, which showed significantly lower bacterial loads in the lungs and reduced lung lesions after direct or cohabitation infection with
A. pleuropneumoniae
. The results demonstrate that transgenic overexpression of PBD-2 in pigs confers enhanced resistance against
A. pleuropneumoniae
infection.
Disruption of Parasitehmgb2Gene Attenuates Plasmodium berghei ANKA Pathogenicity
Authors: Briquet Sylvie , Lawson-Hogban Nadou , Boisson Bertrand , Soares Miguel P. , Péronet Roger , Smith Leanna , Ménard Robert , Huerre Michel , Mécheri Salah , Vaquero Catherine 
Published: April 2015

ABSTRACTEukaryotic high-mobility-group-box (HMGB) proteins are nuclear factors involved in chromatin remodeling and transcription regulation. When released into the extracellular milieu, HMGB1 acts as a proinflammatory cytokine that plays a central role in the pathogenesis of several immune-mediated inflammatory diseases. We found that thePlasmodiumgenome encodes two genuine HMGB factors,PlasmodiumHMGB1 and HMGB2, that encompass, like their human counterparts, a proinflammatory domain. Given that these proteins are released from parasitized red blood cells, we then hypothesized thatPlasmodiumHMGB might contribute to the pathogenesis of experimental cerebral malaria (ECM), a lethal neuroinflammatory syndrome that develops in C57BL/6 (susceptible) mice infected withPlasmodium bergheiANKA and that in many aspects resembles human cerebral malaria elicited byP. falciparuminfection. The pathogenesis of experimental cerebral malaria was suppressed in C57BL/6 mice infected withP. bergheiANKA lacking thehmgb2gene (Δhmgb2ANKA), an effect associated with a reduction of histological brain lesions and with lower expression levels of several proinflammatory genes. The incidence of ECM inpbhmgb2-deficient mice was restored by the administration of recombinantPbHMGB2. Protection from experimental cerebral malaria in Δhmgb2ANKA-infected mice was associated with reduced sequestration in the brain of CD4+and CD8+T cells, including CD8+granzyme B+and CD8+IFN-γ+cells, and, to some extent, neutrophils. This was consistent with a reduced parasite sequestration in the brain, lungs, and spleen, though to a lesser extent than in wild-typeP. bergheiANKA-infected mice. In summary,PlasmodiumHMGB2 acts as an alarmin that contributes to the pathogenesis of cerebral malaria.
S-Inosyl-l-Homocysteine Hydrolase, a Novel Enzyme Involved inS-Adenosyl-l-Methionine Recycling
Authors: Miller Danielle , Xu Huimin , White Robert H. 
Published: April 2015

ABSTRACTS-Adenosyl-l-homocysteine, the product ofS-adenosyl-l-methionine (SAM) methyltransferases, is known to be a strong feedback inhibitor of these enzymes. A hydrolase specific forS-adenosyl-l-homocysteine producesl-homocysteine, which is remethylated to methionine and can be used to regenerate SAM. Here, we show that the annotatedS-adenosyl-l-homocysteine hydrolase inMethanocaldococcus jannaschiiis specific for the hydrolysis and synthesis ofS-inosyl-l-homocysteine, notS-adenosyl-l-homocysteine. This is the first report of an enzyme specific forS-inosyl-l-homocysteine. As withS-adenosyl-l-homocysteine hydrolase, which shares greater than 45% sequence identity with theM. jannaschiihomologue, theM. jannaschiienzyme was found to copurify with bound NAD+and hasKmvalues of 0.64 ± 0.4 mM, 0.0054 ± 0.006 mM, and 0.22 ± 0.11 mM for inosine,l-homocysteine, andS-inosyl-l-homocysteine, respectively. No enzymatic activity was detected withS-adenosyl-l-homocysteine as the substrate in either the synthesis or hydrolysis direction. These results prompted us to redesignate theM. jannaschiienzyme anS-inosyl-l-homocysteine hydrolase (SIHH). Identification of SIHH demonstrates a modified pathway in this methanogen for the regeneration of SAM fromS-adenosyl-l-homocysteine that uses the deamination ofS-adenosyl-l-homocysteine to formS-inosyl-l-homocysteine.IMPORTANCEIn strictly anaerobic methanogenic archaea, such asMethanocaldococcus jannaschii, canonical metabolic pathways are often not present, and instead, unique pathways that are deeply rooted on the phylogenetic tree are utilized by the organisms. Here, we discuss the recycling pathway forS-adenosyl-l-homocysteine, produced fromS-adenosyl-l-methionine (SAM)-dependent methylation reactions, which uses a hydrolase specific forS-inosyl-l-homocysteine, an uncommon metabolite. Identification of the pathways and the enzymes involved in the unique pathways in the methanogens will provide insight into the biochemical reactions that were occurring when life originated.
Escherichia coli YqjA, a Member of the Conserved DedA/Tvp38 Membrane Protein Family, Is a Putative Osmosensing Transporter Required for Growth at Alkaline pH
Authors: Kumar Sujeet , Doerrler William T. 
Published: April 2015

ABSTRACT

The ability to persist and grow under alkaline conditions is an important characteristic of many bacteria. In order to survive at alkaline pH,
Escherichia coli
must maintain a stable cytoplasmic pH of about 7.6. Membrane cation/proton antiporters play a major role in alkaline pH homeostasis by catalyzing active inward proton transport. The DedA/Tvp38 family is a highly conserved membrane protein family of unknown function present in most sequenced genomes. YqjA and YghB are members of the
E. coli
DedA family with 62% amino acid identity and partially redundant functions. We have shown that
E. coli
with Δ
yqjA
and Δ
yghB
mutations cannot properly maintain the proton motive force (PMF) and is compromised in PMF-dependent drug efflux and other PMF-dependent functions. Furthermore, the functions of YqjA and YghB are dependent upon membrane-embedded acidic amino acids, a hallmark of several families of proton-dependent transporters. Here, we show that the Δ
yqjA
mutant (but not Δ
yghB
) cannot grow under alkaline conditions (ranging from pH 8.5 to 9.5), unlike the parent
E. coli
. Overexpression of
yqjA
restores growth at alkaline pH, but only when more than ∼100 mM sodium or potassium is present in the growth medium. Increasing the osmotic pressure by the addition of sucrose enhances the ability of YqjA to support growth under alkaline conditions in the presence of low salt concentrations, consistent with YqjA functioning as an osmosensor. We suggest that YqjA possesses proton-dependent transport activity that is stimulated by osmolarity and that it plays a significant role in the survival of
E. coli
at alkaline pH.

IMPORTANCE
The ability to survive under alkaline conditions is important for many species of bacteria.
Escherichia coli
can grow at pH 5.5 to 9.5 while maintaining a constant cytoplasmic pH of about 7.6. Under alkaline conditions, bacteria rely upon proton-dependent transporters to maintain a constant cytoplasmic pH. The DedA/Tvp38 protein family is a highly conserved but poorly characterized family of membrane proteins. Here, we show that the DedA/Tvp38 protein YqjA is critical for
E. coli
to survive at pH 8.5 to 9.5. YqjA requires sodium and potassium for this function. At low cation concentrations, osmolytes, including sucrose, can facilitate rescue of
E. coli
growth by YqjA at high pH. These data are consistent with YqjA functioning as an osmosensing cation-dependent proton transporter.
Elucidation of the Photorhabdus temperata Genome and Generation of a Transposon Mutant Library To Identify Motility Mutants Altered in Pathogenesis
Authors: Hurst Sheldon , Rowedder Holli , Michaels Brandye , Bullock Hannah , Jackobeck Ryan , Abebe-Akele Feseha , Durakovic Umjia , Gately Jon , Janicki Erik , Tisa Louis S. 
Published: April 2015

ABSTRACTThe entomopathogenic nematodeHeterorhabditis bacteriophoraforms a specific mutualistic association with its bacterial partnerPhotorhabdus temperata. The microbial symbiont is required for nematode growth and development, and symbiont recognition is strain specific. The aim of this study was to sequence the genome ofP. temperataand identify genes that plays a role in the pathogenesis of thePhotorhabdus-Heterorhabditissymbiosis. A draft genome sequence ofP. temperatastrain NC19 was generated. The 5.2-Mb genome was organized into 17 scaffolds and contained 4,808 coding sequences (CDS). A genetic approach was also pursued to identify mutants with altered motility. A bank of 10,000P. temperatatransposon mutants was generated and screened for altered motility patterns. Five classes of motility mutants were identified: (i) nonmotile mutants, (ii) mutants with defective or aberrant swimming motility, (iii) mutant swimmers that do not require NaCl or KCl, (iv) hyperswimmer mutants that swim at an accelerated rate, and (v) hyperswarmer mutants that are able to swarm on the surface of 1.25% agar. The transposon insertion sites for these mutants were identified and used to investigate other physiological properties, including insect pathogenesis. The motility-defective mutant P13-7 had an insertion in the RNase II gene and showed reduced virulence and production of extracellular factors. Genetic complementation of this mutant restored wild-type activity. These results demonstrate a role for RNA turnover in insect pathogenesis and other physiological functions.IMPORTANCEThe relationship betweenPhotorhabdusand entomopathogenic nematodeHeterorhabditisrepresents a well-known mutualistic system that has potential as a biological control agent. The elucidation of the genome of the bacterial partner and role that RNase II plays in its life cycle has provided a greater understanding ofPhotorhabdusas both an insect pathogen and a nematode symbiont.
Novel Role for PilNO in Type IV Pilus Retraction Revealed by Alignment Subcomplex Mutations
Authors: Leighton Tiffany L. , Dayalani Neha , Sampaleanu Liliana M. , Howell P. Lynne , Burrows Lori L. 
Published: April 2015

ABSTRACTType IV pili (T4P) are dynamic protein filaments that mediate bacterial adhesion, biofilm formation, and twitching motility. The highly conserved PilMNOP proteins form an inner membrane alignment subcomplex required for function of the T4P system, though their exact roles are unclear. Three potential interaction interfaces for PilNO were identified: core-core, coiled coils (CC), and the transmembrane segments (TMSs). A high-confidence PilNO heterodimer model was used to select key residues for mutation, and the resulting effects on protein-protein interactions were examined both in a bacterial two-hybrid (BTH) system and in their nativePseudomonas aeruginosacontext. Mutations in the oppositely charged CC regions or the TMS disrupted PilNO heterodimer formation in the BTH assay, while up to six combined mutations in the core failed to disrupt the interaction. When the mutations were introduced into theP. aeruginosachromosome at thepilNorpilOlocus, specific changes at each of the three interfaces—including core mutations that failed to disrupt interactions in the BTH system—abrogated surface piliation and/or impaired twitching motility. Unexpectedly, specific CC mutants were hyperpiliated but nonmotile, a hallmark of pilus retraction defects. These data suggest that PilNO participate in both the extension and retraction of T4P. Our findings support a model of multiple, precise interaction interfaces between PilNO; emphasize the importance of studying protein function in a minimally perturbed context and stoichiometry; and highlight potential target sites for development of small-molecule inhibitors of the T4P system.IMPORTANCEPseudomonas aeruginosais an opportunistic pathogen that uses type IV pili (T4P) for host attachment. The T4P machinery is composed of four cell envelope-spanning subcomplexes. PilN and PilO heterodimers are part of the alignment subcomplex and essential for T4P function. Three potential PilNO interaction interfaces (the core-core, coiled-coil, and transmembrane segment interfaces) were probed using site-directed mutagenesis followed by functional assays in anEscherichia colitwo-hybrid system and inP. aeruginosa. Several mutations blocked T4P assembly and/or motility, including two that revealed a novel role for PilNO in pilus retraction, while other mutations affected extension dynamics. These critical PilNO interaction interfaces represent novel targets for small-molecule inhibitors with the potential to disrupt T4P function.
The Pseudomonas aeruginosa PA14 ABC Transporter NppA1A2BCD Is Required for Uptake of Peptidyl Nucleoside Antibiotics
Authors: Pletzer Daniel , Braun Yvonne , Dubiley Svetlana , Lafon Corinne , Köhler Thilo , Page Malcolm G. P. , Mourez Michael , Severinov Konstantin , Weingart Helge 
Published: April 2015

ABSTRACTAnalysis of the genome sequence ofPseudomonas aeruginosaPA14 revealed the presence of an operon encoding an ABC-type transporter (NppA1A2BCD) showing homology to the Yej transporter ofEscherichia coli. The Yej transporter is involved in the uptake of the peptide-nucleotide antibiotic microcin C, a translation inhibitor that targets the enzyme aspartyl-tRNA synthetase. Furthermore, it was recently shown that the Opp transporter fromP. aeruginosaPAO1, which is identical to Npp, is required for uptake of the uridyl peptide antibiotic pacidamycin, which targets the enzyme translocase I (MraY), which is involved in peptidoglycan synthesis. We used several approaches to further explore the substrate specificity of the Npp transporter. Assays of growth in defined minimal medium containing peptides of various lengths and amino acid compositions as sole nitrogen sources, as well as Biolog Phenotype MicroArrays, showed that the Npp transporter is not required for di-, tri-, and oligopeptide uptake. Overexpression of thenppoperon increased susceptibility not just to pacidamycin but also to nickel chloride and the peptidyl nucleoside antibiotic blasticidin S. Furthermore, heterologous expression of thenppoperon in ayej-deficient mutant ofE. coliresulted in increased susceptibility to albomycin, a naturally occurring sideromycin with a peptidyl nucleoside antibiotic. Additionally, heterologous expression showed that microcin C is recognized by theP. aeruginosaNpp system. Overall, these results suggest that the NppA1A2BCD transporter is involved in the uptake of peptidyl nucleoside antibiotics byP. aeruginosaPA14.IMPORTANCEOne of the world's most serious health problems is the rise of antibiotic-resistant bacteria. There is a desperate need to find novel antibiotic therapeutics that either act on new biological targets or are able to bypass known resistance mechanisms. Bacterial ABC transporters play an important role in nutrient uptake from the environment. These uptake systems could also be exploited by a Trojan horse strategy to facilitate the transport of antibiotics into bacterial cells. Several natural antibiotics mimic substrates of peptide uptake routes. In this study, we analyzed an ABC transporter involved in the uptake of nucleoside peptidyl antibiotics. Our data might help to design drug conjugates that may hijack this uptake system to gain access to cells.
The Tanzanian trauma patients' prehospital experience: a qualitative interview-based study
Authors: Kuzma Kristin , Lim Andrew George , Kepha Bernard , Nalitolela Neema Evelyne , Reynolds Teri A 
Published: April 2015

ObjectivesWe sought to characterise the prehospital experience of Tanzanian trauma patients, and identify barriers and facilitators to implement community-based emergency medical systems (EMS).SettingsOur study was conducted in the emergency department of an urban national referral hospital in Tanzania.ParticipantsA convenience sample of 34 adult trauma patients, or surrogate family members, presenting or referred to an urban referral emergency department in Tanzania for treatment of injury, participated in the study.InterventionsParticipation in semistructured, iteratively developed interviews until saturation of responses was reached.OutcomesA grounded theory-based approach to qualitative analysis was used to identify recurrent themes.ResultsWe characterised numerous deficiencies within the existing clinic-to-hospital referral network, including missed/delayed diagnoses, limited management capabilities at pre-referral facilities and interfacility transfer delays. Potential barriers to EMS implementation include patient financial limitations and lack of insurance, limited public infrastructure and resources, and the credibility of potential first aid responders. Potential facilitators of EMS include communities’ tendency to pool resources, individuals’ trust of other community members to be first aid responders, and faith in community leaders to organise EMS response. Participants expressed a strong desire to learn first aid.ConclusionsThe composite themes generated by the data suggest that there are myriad structural, financial, institutional and cultural barriers to the implementation of a formal prehospital system. However, our analysis also revealed potential facilitators to a first-responder system that takes advantage of close-knit local communities and the trust of recognised leaders in society. The results suggest favourable acceptability for community-based response by trained lay people. There is significant opportunity for care improvements with short trainings and low-cost supply planning. Further research looking at the effects of delay on outcomes in this population is needed.
Tecnologias sonoras terapêuticas
Authors: Costa Celso Rodrigues da , Souza Suelen Tompson , Gontijo Guilherme Pereira , Simões Guilherme Reis , Fonseca Pierre Souza , Bortolus Marcos Vinicius 
Published: April 2015

<p>Objetivo: apresentar os trabalhos finais desenvolvidos na disciplina Processos Criativos e Empreendedorismo. Método: os estudantes devem apresentar ao final da disciplina uma tecnologia para ajudar na aprendizagem ou reabilitação de um cliente em tratamento na Clínica de Musicoterapia. Para a realização do trabalho final da disciplina foram formados grupos de três estudantes, no qual cada grupo deveria desenvolver uma adaptação ou instrumento como recurso terapêutico para um cliente atendido na Clínica de Musicoterapia da UFMG. Resultados: dez trios de estudantes criaram dez instrumentos e duas adaptações. Os dispositivos já renderam três exposições abertas ao público. Os instrumentos e adaptações foram repassados à Clínica de Musicoterapia da UFMG para serem utilizados nos atendimentos. O Projeto de Extensão Paramec da UFMG criou um subgrupo de trabalho para dar continuidade aos trabalhos desenvolvidos na disciplina. Conclusão: a disciplina demonstrou ter grandes sucessos e alcançou os seus objetivos, sendo os instrumentos e adaptações desenvolvidas, as formas expressas dos processos criativos. Foi possível também perceber que uma equipe inter ou transdisciplinar é benéfi ca para uma melhor criação de dispositivos de tecnologia educacional, reabilitadora e assistiva.</p>
A prática do terapeuta ocupacional em iniciativas de geração de trabalho e renda: contribuição dos fundamentos da profissão e das dimensões da categoria trabalho
Authors: Morato Giovana Garcia , Lussi Isabela Aparecida de Oliveira 
Published: April 2015

<p>Os terapeutas ocupacionais vêm buscando aprimorar-se e legitimar-se como profissional diante das mudanças ocorridas no campo da saúde mental e assim vêm aperfeiçoando suas intervenções no nível de prevenção e promoção de saúde, tratamento, reabilitação e inclusão social. Este estudo é um recorte da pesquisa de mestrado cujo objetivo geral foi investigar a prática dos terapeutas ocupacionais que trabalham em iniciativas de geração de trabalho e renda no âmbito da saúde mental no estado de São Paulo. Trata-se de um estudo de abordagem qualitativa do qual participaram 16 terapeutas ocupacionais que atuam em iniciativas de geração de trabalho e renda destinados a usuários da saúde mental no Estado de São Paulo. Para a coleta de dados utilizou-se 2 instrumentos, um questionário semiestruturado e um roteiro de entrevista semiestruturado. Os dados provenientes dos questionários foram analisados de maneira descritiva e as entrevistas foram submetidas à técnica de Análise Temática. Foi possível verificar a concepção amadurecida, por parte das profissionais, acerca da compreensão da atividade e do trabalho nestes contextos que rompem com a concepção terapêutica, demonstrando uma prática condizente com os pressupostos da reabilitação psicossocial e com o que vem sendo preconizado pela política de inclusão social pelo trabalho.</p>