bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypoxic induction of T‐type Ca2+ channels in rat cardiac myocytes: role of HIF‐1α and RhoA/ROCK signalling
Authors: González‐Rodríguez P. , Falcón D. , Castro M. J. , Ureña J. , López‐Barneo J. , Castellano A. 
Published: September 2015

Key points
T‐type Ca2+ channels are expressed in the ventricular myocytes of the fetal and perinatal heart, but are downregulated as development progresses. However, these channels are re‐expressed in adult cardiomyocytes under pathological conditions.
Hypoxia induces the upregulation of the T‐type Ca2+ channel Cav3.2 mRNA in cardiac myocytes, whereas Cav3.1 mRNA is not significantly altered.
The effect of hypoxia on Cav3.2 mRNA requires hypoxia inducible factor‐1α (HIF‐1α) stabilization and involves the small monomeric G‐protein RhoA and its effector ROCKI.
Our results suggest that the hypoxic regulation of the Cav3.2 channels may be involved in the increased probability of developing arrhythmias observed in ischemic situations, and in the pathogenesis of diseases associated with hypoxic Ca2+ overload.
AbstractT‐type Ca2+ channels are expressed in the ventricular myocytes of the fetal and perinatal heart, but are normally downregulated as development progresses. Interestingly, however, these channels are re‐expressed in adult cardiomyocytes under pathological conditions. We investigated low voltage‐activated T‐type Ca2+ channel regulation in hypoxia in rat cardiomyocytes. Molecular studies revealed that hypoxia induces the upregulation of Cav3.2 mRNA, whereas Cav3.1 mRNA is not significantly altered. The effect of hypoxia on Cav3.2 mRNA was time‐ and dose‐dependent, and required hypoxia inducible factor‐1α (HIF‐1α) stabilization. Patch‐clamp recordings confirmed that T‐type Ca2+ channel currents were upregulated in hypoxic conditions, and the addition of 50 μm NiCl2 (a T‐type channel blocker) demonstrated that the Cav3.2 channel is responsible for this upregulation. This increase in current density was not accompanied by significant changes in the Cav3.2 channel electrophysiological properties. The small monomeric G‐protein RhoA and its effector Rho‐associated kinase I (ROCKI), which are known to play important roles in cardiovascular physiology, were also upregulated in neonatal rat ventricular myocytes subjected to hypoxia. Pharmacological experiments indicated that both proteins were involved in the observed upregulation of the Cav3.2 channel and the stabilization of HIF‐1α that occurred in response to hypoxia. These results suggest a possible role for Cav3.2 channels in the increased probability of developing arrhythmias observed in ischaemic situations, and in the pathogenesis of diseases associated with hypoxic Ca2+ overload.
Transient BK outward current enhances motoneurone firing rates during Drosophila larval locomotion
Authors: Kadas Dimitrios , Ryglewski Stefanie , Duch Carsten 
Published: September 2015

Key points
We combine in situ electrophysiology with genetic manipulation in Drosophila larvae aiming to investigate the role of fast calcium‐activated potassium currents for motoneurone firing patterns during locomotion.
We first demonstrate that slowpoke channels underlie fast calcium‐activated potassium currents in these motoneurones.
By conducting recordings in semi‐intact animals that produce crawling‐like movements, we show that slowpoke channels are required specifically in motoneurones for maximum firing rates during locomotion.
Such enhancement of maximum firing rates occurs because slowpoke channels prevent depolarization block by limiting the amplitude of motoneurone depolarization in response to synaptic drive. In addition, slowpoke channels mediate a fast afterhyperpolarization that ensures the efficient recovery of sodium channels from inactivation during high frequency firing.
The results of the present study provide new insights into the mechanisms by which outward conductances facilitate neuronal excitability and also provide direct confirmation of the functional relevance of precisely regulated slowpoke channel properties in motor control.
AbstractA large number of voltage‐gated ion channels, their interactions with accessory subunits, and their post‐transcriptional modifications generate an immense functional diversity of neurones. Therefore, a key challenge is to understand the genetic basis and precise function of specific ionic conductances for neuronal firing properties in the context of behaviour. The present study identifies slowpoke (slo) as exclusively mediating fast activating, fast inactivating BK current (ICF) in larval Drosophila crawling motoneurones. Combining in vivo patch clamp recordings during larval crawling with pharmacology and targeted genetic manipulations reveals that ICF acts specifically in motoneurones to sculpt their firing patterns in response to a given input from the central pattern generating (CPG) networks. First, ICF curtails motoneurone postsynaptic depolarizations during rhythmical CPG drive. Second, ICF is activated during the rising phase of the action potential and mediates a fast afterhyperpolarization. Consequently, ICF is required for maximal intraburst firing rates during locomotion, probably by allowing recovery from inactivation of fast sodium channels and decreased potassium channel activation. This contrasts the common view that outward conductances oppose excitability but is in accordance with reports on transient BK and Kv3 channel function in multiple types of vertebrate neurones. Therefore, our finding that ICF enhances firing rates specifically during bursting patterns relevant to behaviour is probably of relevance to all brains.
Differential short‐term regional effects of early high dose erythropoietin on white matter in preterm lambs after mechanical ventilation
Authors: Barton Samantha K. , McDougall Annie R. A. , Melville Jacqueline M. , Moss Timothy J. M. , Zahra Valerie A. , Lim Tammy , Crossley Kelly J. , Polglase Graeme R. , Tolcos Mary 
Published: September 2015

Key points
Erythropoietin is a neuroprotectant undergoing clinical trial for brain injury in term and preterm infants.
This is the first experimental study to assess the acute effects of erythropoietin on the cerebral white matter in preterm ventilated lambs.
Administration of erythropoietin within minutes of injurious ventilation onset amplified pro‐inflammatory cytokine gene expression in both the periventricular and subcortical white matter compared to the ventilation alone group; erythropoietin had no effect on the area of microglial aggregations in white matter regions with a reduction in cellular density of aggregations in the subcortical white matter only.
Administration of erythropoietin in conjunction with injurious ventilation increased gene expression of tight junction proteins and reduced protein extravasation from blood vessels in the cerebral white matter.
Given the increase in inflammation after erythropoietin, we recommend further investigation into its use as a treatment for ventilated preterm babies prior to clinical translation.
AbstractInadvertently injurious ventilation of preterm neonates in the delivery room can cause cerebral white matter (WM) inflammation and injury. We investigated the impact of an early high dose of recombinant human erythropoietin (EPO) on ventilation‐induced WM changes in preterm lambs. Injurious ventilation, targeting a VT of 15 ml kg−1 with no positive end‐expiratory pressure, was initiated for 15 min in preterm lambs (0.85 gestation). Conventional ventilation was continued for a further 105 min. Lambs received either 5000 IU kg−1 of EPO (EPREX®; Vent+EPO; n = 6) or vehicle (Vent; n = 8) via an umbilical vein at 4 ± 2 min. Markers of WM injury and inflammation were assessed using quantitative real‐time PCR (qPCR) and immunohistochemistry and compared to a group of unventilated controls (UVC; n = 4). In Vent+EPO lambs compared to Vent lambs: (i) interleukin (IL)‐1β and IL‐6 mRNA levels in the periventricular WM and IL‐8 mRNA levels in the subcortical WM were higher (P < 0.05 for all); (ii) the density of microglia within the aggregations was not different in the periventricular WM and was lower in the subcortical WM (P = 0.001); (iii) the density of astrocytes was lower in the subcortical WM (P = 0.002); (iv) occludin and claudin‐1 mRNA levels were higher in the periventricular WM (P < 0.02 for all) and (vi) the number of blood vessels with protein extravasation was lower (P < 0.05). Recombinant human EPO had variable regional effects within the WM when administered during injurious ventilation. The adverse short‐term outcomes discourage the use of early high dose EPO administration in preterm ventilated babies.
Comparative Accuracy of the InBios Scrub Typhus Detect IgM Rapid Test for the Detection of IgM Antibodies by Using Conventional Serology
Authors: Kingston Hugh W. F. , Blacksell Stuart D. , Tanganuchitcharnchai Ampai , Laongnualpanich Achara , Basnyat Buddha , Day Nicholas P. J. , Paris Daniel H. 
Published: September 2015

ABSTRACT
This study investigated the comparative accuracy of a recombinant 56-kDa type-specific antigen-based rapid diagnostic test (RDT) for scrub typhus for the detection of IgM antibodies by using conventional serology in well-characterized serum samples from undifferentiated febrile illness patients. The RDT showed high specificity and promising comparative accuracy, with 82% sensitivity and 98% specificity for samples defined positive at an IgM indirect immunofluorescence assay positivity cutoff titer of ≥1:1,600 versus 92% and 95% at ≥1:6,400, respectively.
First Case of Fungemia Due to Pseudozyma aphidis in a Pediatric Patient with Osteosarcoma in Latin America
Authors: Orecchini Luisa Alejandra , Olmos Eugenia , Taverna Constanza Giselle , Murisengo Omar Alejandro , Szuzs Wanda , Vivot Walter , Córdoba Susana , Bosco-Borgeat María Eugenia , Montanaro Patricia Cristina 
Published: September 2015

ABSTRACT

We report the first case of blood infection due to
Pseudozyma aphidis
in Latin America. We contribute evidence showing this organism to be a potential human pathogen, and we provide new data about its identification, drug susceptibility, and treatment outcome.
Simultaneous Presence of Insertion Sequence Excision Enhancer and Insertion Sequence IS
629
Correlates with Increased Diversity and Virulence in Shiga Toxin-Producing Escherichia coli
Authors: Toro M. , Rump L. V. , Cao G. , Meng J. , Brown E. W. , Gonzalez-Escalona N. 
Published: September 2015

ABSTRACT

Although new serotypes of enterohemorrhagic
Escherichia coli
(EHEC) emerge constantly, the mechanisms by which these new pathogens arise and the reasons emerging serotypes tend to carry more virulence genes than other
E. coli
are not understood. An insertion sequence (IS) excision enhancer (IEE) was discovered in EHEC O157:H7 that promoted the excision of IS
3
family members and generating various genomic deletions. One IS
3
family member, IS
629
, actively transposes and proliferates in EHEC O157:H7 and enterotoxigenic
E. coli
(ETEC) O139 and O149. The simultaneous presence of the IEE and IS
629
(and other IS
3
family members) may be part of a system promoting not only adaptation and genome diversification in
E. coli
O157:H7 but also contributing to the development of pathogenicity among predominant serotypes. Prevalence comparisons of these elements in 461 strains, representing 72 different serotypes and 5 preassigned seropathotypes (SPT) A to E, showed that the presence of these two elements simultaneously was serotype specific and associated with highly pathogenic serotypes (O157 and top non-O157 Shiga toxin-producing Escherichia coli [STEC]) implicated in outbreaks and sporadic cases of human illness (SPT A and B). Serotypes lacking one or both elements were less likely to have been isolated from clinical cases. Our comparisons of IEE sequences showed sequence variations that could be divided into at least three clusters. Interestingly, the IEE sequences from O157 and the top 10 non-O157 STEC serotypes fell into clusters I and II, while less commonly isolated serotypes O5 and O174 fell into cluster III. These results suggest that IS
629
and IEE elements may be acting synergistically to promote genome plasticity and genetic diversity among STEC strains, enhancing their abilities to adapt to hostile environments and rapidly take up virulence factors.
Staphylococcus aureus Colonization and Strain Type at Various Body Sites among Patients with a Closed Abscess and Uninfected Controls at U.S. Emergency Departments
Authors: Albrecht Valerie S. , Limbago Brandi M. , Moran Gregory J. , Krishnadasan Anusha , Gorwitz Rachel J. , McDougal Linda K. , Talan David A. 
Published: September 2015

ABSTRACT

Community-associated methicillin-resistant
Staphylococcus aureus
(CA-MRSA) is a prevalent cause of skin and soft tissue infections (SSTI), but the association between CA-MRSA colonization and infection remains uncertain. We studied the carriage frequency at several body sites and the diversity of
S. aureus
strains from patients with and without SSTI. Specimens from the nares, throat, rectum, and groin of case subjects with a closed skin abscess (i.e., without drainage) and matched control subjects without a skin infection (
n
= 147 each) presenting to 10 U.S. emergency departments were cultured using broth enrichment; wound specimens were cultured from abscess cases. Methicillin resistance testing and
spa
typing were performed for all
S. aureus
isolates.
S. aureus
was found in 85/147 (57.8%) of abscesses; 49 isolates were MRSA, and 36 were methicillin-susceptible
S. aureus
(MSSA). MRSA colonization was more common among cases (59/147; 40.1%) than among controls (27/147; 18.4%) overall (
P
< 0.001) and at each body site; no differences were observed for MSSA.
S. aureus
-infected subjects were usually (75/85) colonized with the infecting strain; among MRSA-infected subjects, this was most common in the groin. The CC8 lineage accounted for most of both infecting and colonizing isolates, although more than 16 distinct strains were identified. Nearly all MRSA infections were inferred to be USA300. There was more diversity among colonizing than infecting isolates and among those isolated from controls versus cases. CC8
S. aureus
is a common colonizer of persons with and without skin infections. Detection of
S. aureus
colonization, and especially MRSA, may be enhanced by extranasal site culture.
One-Step Multiplex PCR Assay for Differentiating Proposed New Species “Clostridium neonatale” from Closely Related Species
Authors: Ferraris Laurent , Schönherr Sophia , Bouvet Philippe , Dauphin Brunhilde , Popoff Michel , Butel Marie Jose , Aires Julio 
Published: September 2015

ABSTRACT

“
Clostridium neonatale
” sp. nov., previously involved in an outbreak of neonatal necrotizing enterocolitis, was recently proposed as a new species of the
Clostridium
genus
sensu stricto
. We developed a one-step multiplex colony PCR for
C. neonatale
identification and investigated
C. neonatale
intestinal colonization frequency in healthy preterm neonates.
New Diagnostic Insights for Macrorhabdus ornithogaster Infection
Authors: Borrelli Luca , Dipineto Ludovico , Rinaldi Laura , Romano Violante , Noviello Emilio , Menna Lucia Francesca , Cringoli Giuseppe , Fioretti Alessandro 
Published: September 2015

ABSTRACT

The aim of this study was to propose the use of a new rapid and user-friendly diagnostic tool for the detection of
Macrorhabdus
ornithogaster
infection in birds. The current report focuses on the diagnostic feasibility of different methods, with particular emphasis on the application of the mini-Flotac technique for the diagnosis of
M
.
ornithogaster
infection. The mini-Flotac method is particularly tailored for epidemiological monitoring and surveillance, where large numbers of fecal samples must be rapidly, yet reliably, examined. Gram staining, as the standard method, was used to validate the reliability of the mini-Flotac method. This tool has not yet been used in avian species or in the diagnosis of yeast infections. In our study,
M. ornithogaster
showed excellent performance in a flotation assay, which had not been demonstrated previously. Our results suggest that the mini-Flotac method is a valid, sensitive, and potentially low-cost alternative technique for use in the diagnosis of this yeast infection in birds.
Standardization of Quantitative PCR for Human T-Cell Leukemia Virus Type 1 in Japan: a Collaborative Study
Authors: Kuramitsu Madoka , Okuma Kazu , Yamochi Tadanori , Sato Tomoo , Sasaki Daisuke , Hasegawa Hiroo , Umeki Kazumi , Kubota Ryuji , Sobata Rieko , Matsumoto Chieko , Kaneko Noriaki , Naruse Isao , Yamagishi Makoto , Nakashima Makoto , Momose Haruka , Araki Kumiko , Mizukami Takuo , Mizusawa Saeko , Okada Yoshiaki , Ochiai Masaki , Utsunomiya Atae , Koh Ki-Ryang , Ogata Masao , Nosaka Kisato , Uchimaru Kaoru , Iwanaga Masako , Sagara Yasuko , Yamano Yoshihisa , Satake Masahiro , Okayama Akihiko , Mochizuki Manabu , Izumo Shuji , Saito Shigeru , Itabashi Kazuo , Kamihira Shimeru , Yamaguchi Kazunari , Watanabe Toshiki , Hamaguchi Isao 
Published: September 2015

ABSTRACT
Quantitative PCR (qPCR) analysis of human T-cell leukemia virus type 1 (HTLV-1) was used to assess the amount of HTLV-1 provirus DNA integrated into the genomic DNA of host blood cells. Accumulating evidence indicates that a high proviral load is one of the risk factors for the development of adult T-cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis. However, interlaboratory variability in qPCR results makes it difficult to assess the differences in reported proviral loads between laboratories. To remedy this situation, we attempted to minimize discrepancies between laboratories through standardization of HTLV-1 qPCR in a collaborative study. TL-Om1 cells that harbor the HTLV-1 provirus were serially diluted with peripheral blood mononuclear cells to prepare a candidate standard. By statistically evaluating the proviral loads of the standard and those determined using in-house qPCR methods at each laboratory, we determined the relative ratios of the measured values in the laboratories to the theoretical values of the TL-Om1 standard. The relative ratios of the laboratories ranged from 0.84 to 4.45. Next, we corrected the proviral loads of the clinical samples from HTLV-1 carriers using the relative ratio. As expected, the overall differences between the laboratories were reduced by half, from 7.4-fold to 3.8-fold on average, after applying the correction. HTLV-1 qPCR can be standardized using TL-Om1 cells as a standard and by determining the relative ratio of the measured to the theoretical standard values in each laboratory.
Recurrent Methicillin-Resistant Staphylococcus aureus Cutaneous Abscesses and Selection of Reduced Chlorhexidine Susceptibility during Chlorhexidine Use
Authors: Johnson Ryan C. , Schlett Carey D. , Crawford Katrina , Lanier Jeffrey B. , Merrell D. Scott , Ellis Michael W. 
Published: September 2015

ABSTRACT

We describe the selection of reduced chlorhexidine susceptibility during chlorhexidine use in a patient with two episodes of cutaneous USA300 methicillin-resistant
Staphylococcus aureus
abscess. The second clinical isolate harbors a novel plasmid that encodes the QacA efflux pump. Greater use of chlorhexidine for disease prevention warrants surveillance for resistance.
Evaluation of the RealTime HIV-1, Xpert HIV-1, and Aptima HIV-1 Quant Dx Assays in Comparison to the NucliSens EasyQ HIV-1 v2.0 Assay for Quantification of HIV-1 Viral Load
Authors: Mor Orna , Gozlan Yael , Wax Marina , Mileguir Fernando , Rakovsky Avia , Noy Bina , Mendelson Ella , Levy Itzchak 
Published: September 2015

ABSTRACT

HIV-1 RNA monitoring, both before and during antiretroviral therapy, is an integral part of HIV management worldwide. Measurements of HIV-1 viral loads are expected to assess the copy numbers of all common HIV-1 subtypes accurately and to be equally sensitive at different viral loads. In this study, we compared for the first time the performance of the NucliSens v2.0, RealTime HIV-1, Aptima HIV-1 Quant Dx, and Xpert HIV-1 viral load assays. Plasma samples (
n
= 404) were selected on the basis of their NucliSens v2.0 viral load results and HIV-1 subtypes. Concordance, linear regression, and Bland-Altman plots were assessed, and mixed-model analysis was utilized to compare the analytical performance of the assays for different HIV-1 subtypes and for low and high HIV-1 copy numbers. Overall, high concordance (>83.89%), high correlation values (Pearson
r
values of >0.89), and good agreement were observed among all assays, although the Xpert and Aptima assays, which provided the most similar outputs (estimated mean viral loads of 2.67 log copies/ml [95% confidence interval [CI], 2.50 to 2.84 log copies/ml] and 2.68 log copies/ml [95% CI, 2.49 to 2.86 log copies/ml], respectively), correlated best with the RealTime assay (89.8% concordance, with Pearson
r
values of 0.97 to 0.98). These three assays exhibited greater precision than the NucliSens v2.0 assay. All assays were equally sensitive for subtype B and AG/G samples and for samples with viral loads of 1.60 to 3.00 log copies/ml. The NucliSens v2.0 assay underestimated A1 samples and those with viral loads of >3.00 log copies/ml. The RealTime assay tended to underquantify subtype C (compared to the Xpert and Aptima assays) and subtype A1 samples. The Xpert and Aptima assays were equally efficient for detection of all subtypes and viral loads, which renders these new assays most suitable for clinical HIV laboratories.
Clonal Diversification and Changes in Lipid Traits and Colony Morphology in Mycobacterium abscessus Clinical Isolates
Authors: Park In Kwon , Hsu Amy P. , Tettelin Hervé , Shallom Shamira J. , Drake Steven K. , Ding Li , Wu Un-In , Adamo Nick , Prevots D. Rebecca , Olivier Kenneth N. , Holland Steven M. , Sampaio Elizabeth P. , Zelazny Adrian M. 
Published: September 2015

ABSTRACT

The smooth-to-rough colony morphology shift in
Mycobacterium abscessus
has been implicated in loss of glycopeptidolipid (GPL), increased pathogenicity, and clinical decline in cystic fibrosis (CF) patients. However, the evolutionary phenotypic and genetic changes remain obscure. Serial isolates from nine non-CF patients with persistent
M. abscessus
infection were characterized by colony morphology, lipid profile via thin-layer chromatography and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS), sequencing of eight genes in the GPL locus, and expression level of
fadD23
, a key gene involved in the biosynthesis of complex lipids. All 50 isolates were typed as
M. abscessus
subspecies
abscessus
and were clonally related within each patient. Rough isolates, all lacking GPL, predominated at later disease stages, some showing variation within rough morphology. While most (77%) rough isolates harbored detrimental mutations in
mps1
and
mps2
, 13% displayed previously unreported mutations in
mmpL4a
and
mmpS4
, the latter yielding a putative GPL precursor. Two isolates showed no deleterious mutations in any of the eight genes sequenced. Mixed populations harboring different GPL locus mutations were detected in 5 patients, demonstrating clonal diversification, which was likely overlooked by conventional acid-fast bacillus (AFB) culture methods. Our work highlights applications of MALDI-TOF MS beyond identification, focusing on mycobacterial lipids relevant in virulence and adaptation. Later isolates displayed accumulation of triacylglycerol and reduced expression of
fadD23
, sometimes preceding rough colony onset. Our results indicate that clonal diversification and a shift in lipid metabolism, including the loss of GPL, occur during chronic lung infection with
M. abscessus
. GPL loss alone may not account for all traits associated with rough morphology.