bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compartmentalized gene expression of toll‐like receptors 2, 4 and 9 in the brain and peripheral lymphoid organs during canine visceral leishmaniasis
Authors: Melo G. D. , Silva J. E. S. , Grano F. G. , Homem C. G. , Machado G. F. 
Published: October 2014

SummaryVisceral leishmaniasis is an important parasitic disease that affects humans and animals. The response against the protozoan involves the interaction of both innate and adaptive branches of the immune system, and an important immune sensor is represented by the toll‐like receptor (TLR) family. Here, we investigated the pattern of TLR‐2, TLR‐4 and TLR‐9 gene expression in different compartments (brain, choroid plexus, spleen and lymph node) of dogs naturally infected with Leishmania infantum. Gene expression of the TLRs varied according to the compartment evaluated. In the brain, there was only an upregulation of TLR‐2, whereas in the choroid plexus, TLR‐2 and TLR‐9 were both upregulated. Further, the peripheral lymphoid organs (spleen and lymph nodes) showed increased TLR‐2 and TLR‐4 expression. This study provides the first insight about TLR expression in the central nervous system of infected dogs, and gives additional evidence of the compartmentalization of the immune response during visceral leishmaniasis.
Post‐encystment/established immunity in cystic echinococcosis: is it really that simple?
Authors: Rogan M. T. , Bodell A. J. , Craig P. S. 
Published: October 2014

SummaryIn 1982, Rickard & Williams stated that immunity to larval taeniid cestodes could be divided into two different phases: the establishment phase, operating against oncospheres, and the established phase, operating against established metacestodes in the tissues. These concepts were largely based on experimental and veterinary data. As a result of subsequent research combined with clinical data, we can consider that, for metacestodes of Echinococcus spp, a single established phase is probably too simple a concept. These parasites show developmental changes in different hosts over time, the most significant being growth, fertility and degeneration. Recent clinical cyst classifications (WHO/IWGE) have highlighted that all hydatid cysts are morphologically not the same. This is important for treatment but fails to completely address variation in the host/parasite response and the understanding of parasite survival. This review attempts to relate the immunological and developmental data obtained from experimental, veterinary and medical studies to update our understanding of established immunity against E. granulosus. It proposes that a single ‘Established’ phase for E. granulosus could be subdivided into four additional phases: maturing; stable; unstable and degenerative. Combining this type of information with existing cyst classification systems could significantly benefit our understanding of the parasites immunobiology.
Living on the edge: the role of geography and environment in structuring genetic variation in the southernmost populations of a tropical oak
Authors: Ortego J. , Bonal R. , Muñoz A. , Espelta J. M. 
Published: October 2014

AbstractUnderstanding the factors determining genetic diversity and structure in peripheral populations is a long‐standing goal of evolutionary biogeography, yet little empirical information is available for tropical species. In this study, we combine information from nuclear microsatellite markers and niche modelling to analyse the factors structuring genetic variation across the southernmost populations of the tropical oak Quercus segoviensis. First, we tested the hypothesis that genetic variability decreases with population isolation and increases with local habitat suitability and stability since the Last Glacial Maximum (LGM). Second, we employed a recently developed multiple matrix regression with randomisation (MMRR) approach to study the factors associated with genetic divergence among the studied populations and test the relative contribution of environmental and geographic isolation to contemporary patterns of genetic differentiation. We found that genetic diversity was negatively correlated with average genetic differentiation with other populations, indicating that isolation and limited gene flow have contributed to erode genetic variability in some populations. Considering the relatively small size of the study area (<120 km), analyses of genetic structure indicate a remarkable inter‐population genetic differentiation. Environmental dissimilarity and differences in current and past climate niche suitability and their additive effects were not associated with genetic differentiation after controlling for geographic distance, indicating that local climate does not contribute to explain spatial patterns of genetic structure. Overall, our data indicate that geographic isolation, but not current or past climate, is the main factor determining contemporary patterns of genetic diversity and structure within the southernmost peripheral populations of this tropical oak.
Frequency‐dependent facilitation of synaptic throughput via postsynaptic NMDA receptors in the nucleus of the solitary tract
Authors: Zhao Huan , Peters James H. , Zhu Mingyan , Page Stephen J. , Ritter Robert C. , Appleyard Suzanne M. 
Published: October 2014

Key points

Hindbrain NMDA receptors play important roles in reflexive and behavioural responses to vagal activation.

NMDA receptors have also been shown to contribute to the synaptic responses of neurons in the nucleus of the solitary tract (NTS), but their exact role remains unclear.

In this study we used whole cell patch‐clamping techniques in rat horizontal brain slice to investigate the role of NMDA receptors in the fidelity of transmission across solitary tract afferent–NTS neuron synapses.

Results show that NMDA receptors contribute up to 70% of the charge transferred across the synapse at high (>5 Hz) firing rates, but have little contribution at lower firing frequencies. Results also show that NMDA receptors critically contribute to the fidelity of transmission across these synapses during high frequency (>5 Hz) afferent discharge rates.

This novel role of NMDA receptors may explain in part how primary visceral afferents, including vagal afferents, can maintain fidelity of transmission across a broad range of firing frequencies.

AbstractNeurons within the nucleus of the solitary tract (NTS) receive vagal afferent innervations that initiate gastrointestinal and cardiovascular reflexes. Glutamate is the fast excitatory neurotransmitter released in the NTS by vagal afferents, which arrive there via the solitary tract (ST). ST stimulation elicits excitatory postsynaptic currents (EPSCs) in NTS neurons mediated by both AMPA‐ and NMDA‐type glutamate receptors (‐Rs). Vagal afferents exhibit a high probability of vesicle release and exhibit robust frequency‐dependent depression due to presynaptic vesicle depletion. Nonetheless, synaptic throughput is maintained even at high frequencies of afferent activation. Here we test the hypothesis that postsynaptic NMDA‐Rs are essential in maintaining throughput across ST–NTS synapses. Using patch clamp electrophysiology in horizontal brainstem slices, we found that NMDA‐Rs, including NR2B subtypes, carry up to 70% of the charge transferred across the synapse during high frequency stimulations (>5 Hz). In contrast, their relative contribution to the ST‐EPSC is much less during low (<2 Hz) frequency stimulations. Afferent‐driven activation of NMDA‐Rs produces a sustained depolarization during high, but not low, frequencies of stimulation as a result of relatively slow decay kinetics. Hence, NMDA‐Rs are critical for maintaining action potential generation at high firing rates. These results demonstrate a novel role for NMDA‐Rs enabling a high probability of release synapse to maintain the fidelity of synaptic transmission during high frequency firing when glutamate release and AMPA‐R responses are reduced. They also suggest why NMDA‐Rs are critical for responses that may depend on high rates of afferent discharge.
Skeletal muscle ATP turnover by 31P magnetic resonance spectroscopy during moderate and heavy bilateral knee extension
Authors: Cannon Daniel T. , Bimson William E. , Hampson Sophie A. , Bowen T. Scott , Murgatroyd Scott R. , Marwood Simon , Kemp Graham J. , Rossiter Harry B. 
Published: October 2014

Key points
Heavy‐intensity exercise causes a progressive increase in energy demand that contributes to exercise limitation.
This inefficiency arises within the locomotor muscles and is thought to be due to an increase in the ATP cost of power production; however, the responsible mechanism is unresolved.
We measured whole‐body O2 uptake and skeletal muscle ATP turnover by combined pulmonary gas exchange and magnetic resonance spectroscopy during moderate and heavy exercise in humans.
Muscle ATP synthesis rate increased throughout constant‐power heavy exercise, but this increase was unrelated to the progression of whole‐body inefficiency.
Our data indicate that the increased ATP requirement is not the sole cause of inefficiency during heavy exercise, and other mechanisms, such as increased O2 cost of ATP resynthesis, may contribute.
AbstractDuring constant‐power high‐intensity exercise, the expected increase in oxygen uptake () is supplemented by a slow component (), reflecting reduced work efficiency, predominantly within the locomotor muscles. The intracellular source of inefficiency is postulated to be an increase in the ATP cost of power production (an increase in P/W). To test this hypothesis, we measured intramuscular ATP turnover with 31P magnetic resonance spectroscopy (MRS) and whole‐body during moderate (MOD) and heavy (HVY) bilateral knee‐extension exercise in healthy participants (n = 14). Unlocalized 31P spectra were collected from the quadriceps throughout using a dual‐tuned (1H and 31P) surface coil with a simple pulse‐and‐acquire sequence. Total ATP turnover rate (ATPtot) was estimated at exercise cessation from direct measurements of the dynamics of phosphocreatine (PCr) and proton handling. Between 3 and 8 min during MOD, there was no discernable (mean ± SD, 0.06 ± 0.12 l min−1) or change in [PCr] (30 ± 8 vs. 32 ± 7 mm) or ATPtot (24 ± 14 vs. 17 ± 14 mm min−1; each P = n.s.). During HVY, the was 0.37 ± 0.16 l min−1 (22 ± 8%), [PCr] decreased (19 ± 7 vs. 18 ± 7 mm, or 12 ± 15%; P < 0.05) and ATPtot increased (38 ± 16 vs. 44 ± 14 mm min−1, or 26 ± 30%; P < 0.05) between 3 and 8 min. However, the increase in ATPtot (ΔATPtot) was not correlated with the during HVY (r2 = 0.06; P = n.s.). This lack of relationship between ΔATPtot and , together with a steepening of the [PCr]– relationship in HVY, suggests that reduced work efficiency during heavy exercise arises from both contractile (P/W) and mitochondrial sources (the O2 cost of ATP resynthesis; P/O).
Prostaglandin E2 differentially modulates the central control of eupnoea, sighs and gasping in mice
Authors: Koch Henner , Caughie Cali , Elsen Frank P. , Doi Atsushi , Garcia Alfredo J. , Zanella Sebastien , Ramirez Jan‐Marino 
Published: October 2014

Key points
Prostaglandin E2 (PGE2) augments distinct inspiratory motor patterns, generated within the preBötzinger complex (preBötC), in a dose‐dependent way. The frequency of sighs and gasping are stimulated at low concentrations, while the frequency of eupnoea increases only at high concentrations.
We used in vivo microinjections into the preBötC and in vitro isolated brainstem slice preparations to investigate the dose‐dependent effects of PGE2 on the preBötC activity.
Synaptic measurements in whole cell voltage clamp recordings of inspiratory neurons revealed no changes in inhibitory or excitatory synaptic transmission in response to PGE2 exposure.
In current clamp recordings obtained from inspiratory neurons of the preBötC, we found an increase in the frequency and amplitude of bursting activity in neurons with intrinsic bursting properties after exposure to PGE2.
Riluzole, a blocker of the persistent sodium current, abolished the effect of PGE2 on sigh activity, while flufenamic acid, a blocker of the calcium‐activated non‐selective cation conductance, abolished the effect on eupnoeic activity caused by PGE2.AbstractProstaglandins are important regulators of autonomic functions in the mammalian organism. Here we demonstrate in vivo that prostaglandin E2 (PGE2) can differentially increase the frequency of eupnoea (normal breathing) and sighs (augmented breaths) when injected into the preBötzinger complex (preBötC), a medullary area that is critical for breathing. Low concentrations of PGE2 (100–300 nm) increased the sigh frequency, while higher concentrations (1–2 μm) were required to increase the eupnoeic frequency. The concentration‐dependent effects were similarly observed in the isolated preBötC. This in vitro preparation also revealed that riluzole, a blocker of the persistent sodium current (INap), abolished the modulatory effect on sighs, while flufenamic acid, an antagonist for the calcium‐activated non‐selective cation conductance (ICAN) abolished the effect of PGE2 on fictive eupnoea at higher concentrations. At the cellular level PGE2 significantly increased the amplitude and frequency of intrinsic bursting in inspiratory neurons. By contrast PGE2 affected neither excitatory nor inhibitory synaptic transmission. We conclude that PGE2 differentially modulates sigh, gasping and eupnoeic activity by differentially increasing INap and ICAN currents in preBötC neurons.
Metabolic Engineering of a Glycerol-Oxidative Pathway in Lactobacillus panis PM1 for Utilization of Bioethanol Thin Stillage: Potential To Produce Platform Chemicals from Glycerol
Authors: Kang Tae Sun , Korber Darren R. , Tanaka Takuji 
Published: October 2014

ABSTRACT

Lactobacillus panis
PM1 has the ability to produce 1,3-propanediol (1,3-PDO) from thin stillage (TS), which is the major waste material after bioethanol production, and is therefore of significance. However, the fact that
L. panis
PM1 cannot use glycerol as a sole carbon source presents a considerable problem in terms of utilization of this strain in a wide range of industrial applications. Accordingly,
L. panis
PM1 was genetically engineered to directly utilize TS as a fermentable substrate for the production of valuable platform chemicals without the need for exogenous nutrient supplementation (e.g., sugars and nitrogen sources). An artificial glycerol-oxidative pathway, comprised of glycerol facilitator, glycerol kinase, glycerol 3-phosphate dehydrogenase, triosephosphate isomerase, and NADPH-dependent aldehyde reductase genes of
Escherichia coli
, was introduced into
L. panis
PM1 in order to directly utilize glycerol for the production of energy for growth and value-added chemicals. A pH 6.5 culture converted glycerol to mainly lactic acid (85.43 mM), whereas a significant amount of 1,3-propanediol (59.96 mM) was formed at pH 7.5. Regardless of the pH, ethanol (82.16 to 83.22 mM) was produced from TS fermentations, confirming that the artificial pathway metabolized glycerol for energy production and converted it into lactic acid or 1,3-PDO and ethanol in a pH-dependent manner. This study demonstrates the cost-effective conversion of TS to value-added chemicals by the engineered PM1 strain cultured under industrial conditions. Thus, application of this strain or these research findings can contribute to reduced costs of bioethanol production.
Construction of a Quadruple Auxotrophic Mutant of an Industrial Polyploid Saccharomyces cerevisiae Strain by Using RNA-Guided Cas9 Nuclease
Authors: Zhang Guo-Chang , Kong In Iok , Kim Heejin , Liu Jing-Jing , Cate Jamie H. D. , Jin Yong-Su 
Published: October 2014

ABSTRACT

Industrial polyploid yeast strains harbor numerous beneficial traits but suffer from a lack of available auxotrophic markers for genetic manipulation. Here we demonstrated a quick and efficient strategy to generate auxotrophic markers in industrial polyploid yeast strains with the RNA-guided Cas9 nuclease. We successfully constructed a quadruple auxotrophic mutant of a popular industrial polyploid yeast strain,
Saccharomyces cerevisiae
ATCC 4124, with
ura3
,
trp1
,
leu2
, and
his3
auxotrophies through RNA-guided Cas9 nuclease. Even though multiple alleles of auxotrophic marker genes had to be disrupted simultaneously, we observed knockouts in up to 60% of the positive colonies after targeted gene disruption. In addition, growth-based spotting assays and fermentation experiments showed that the auxotrophic mutants inherited the beneficial traits of the parental strain, such as tolerance of major fermentation inhibitors and high temperature. Moreover, the auxotrophic mutants could be transformed with plasmids containing selection marker genes. These results indicate that precise gene disruptions based on the RNA-guided Cas9 nuclease now enable metabolic engineering of polyploid
S. cerevisiae
strains that have been widely used in the wine, beer, and fermentation industries.
Detection and Quantification of Flavobacterium psychrophilum-Specific Bacteriophages
In Vivo
in Rainbow Trout upon Oral Administration: Implications for Disease Control in Aquaculture
Authors: Christiansen Rói Hammershaimb , Dalsgaard Inger , Middelboe Mathias , Lauritsen Anne H. , Madsen Lone 
Published: October 2014

ABSTRACT

The use of bacteriophages in the treatment and prevention of infections by the fish pathogen
Flavobacterium psychrophilum
has attracted increased attention in recent years. It has been shown recently that phage delivery via the parenteral route resulted in immediate distribution of phages to the circulatory system and the different organs. However, little is known about phage dispersal and survival
in vivo
in rainbow trout after delivery via the oral route. Here we examined the dispersal and survival of
F. psychrophilum
phage FpV-9
in vivo
in juvenile rainbow trout after administration by three different methods—bath, oral intubation into the stomach, and phage-coated feed—with special emphasis on the oral route of delivery. Phages could be detected in all the organs investigated (intestine, spleen, brain, and kidney) 0.5 h postadministration, reaching concentrations as high as ∼10
5
PFU mg intestine
−1
and ∼10
3
PFU mg spleen
−1
within the first 24 h following the bath and ∼10
7
PFU mg intestine
−1
and ∼10
4
PFU mg spleen
−1
within the first 24 h following oral intubation. The phages were most persistent in the organs for the first 24 h and then decreased exponentially; no phages were detected after 83 h in the organs investigated. Phage administration via feed resulted in the detection of phages in the intestine, spleen, and kidney 1 h after feeding. Average concentrations of ∼10
4
PFU mg intestine
−1
and ∼10
1
PFU mg spleen
−1
were found throughout the experimental period (200 h) following continuous delivery of phages with feed. These experiments clearly demonstrate the ability of the phages to survive passage through the fish stomach and to penetrate the intestinal barrier and enter the circulatory system after oral delivery, although the quantity of phages found in the spleen was 100- to 1,000-fold lower than that in the intestine. It was also shown that phages could tolerate long periods of desiccation on the feed pellets, with 60% survival after storage at −80°C, and 10% survival after storage at 5°C, for ∼8 months. Continuous delivery of phages via coated feed pellets constitutes a promising method of treatment and especially prevention of rainbow trout fry syndrome.
Aerobic Biodegradation of 2,4-Dinitroanisole by Nocardioides sp. Strain JS1661
Authors: Fida Tekle Tafese , Palamuru Shannu , Pandey Gunjan , Spain Jim C. 
Published: October 2014

ABSTRACT

2,4-Dinitroanisole (DNAN) is an insensitive munition ingredient used in explosive formulations as a replacement for 2,4,6-trinitrotoluene (TNT). Little is known about the environmental behavior of DNAN. There are reports of microbial transformation to dead-end products, but no bacteria with complete biodegradation capability have been reported.
Nocardioides
sp. strain JS1661 was isolated from activated sludge based on its ability to grow on DNAN as the sole source of carbon and energy. Enzyme assays indicated that the first reaction involves hydrolytic release of methanol to form 2,4-dinitrophenol (2,4-DNP). Growth yield and enzyme assays indicated that 2,4-DNP underwent subsequent degradation by a previously established pathway involving formation of a hydride-Meisenheimer complex and release of nitrite. Identification of the genes encoding the key enzymes suggested recent evolution of the pathway by recruitment of a novel hydrolase to extend the well-characterized 2,4-DNP pathway.
Protein Phosphatase 2A (PP2A) Regulatory Subunits ParA and PabA Orchestrate Septation and Conidiation and Are Essential for PP2A Activity in Aspergillus nidulans
Authors: Zhong Guo-wei , Jiang Ping , Qiao Wei-ran , Zhang Yuan-wei , Wei Wen-fan , Lu Ling 
Published: October 2014

ABSTRACT

Protein phosphatase 2A (PP2A) is a major intracellular protein phosphatase that regulates multiple aspects of cell growth and metabolism. Different activities of PP2A and subcellular localization are determined by its regulatory subunits. Here we identified and characterized the functions of two protein phosphatase regulatory subunit homologs, ParA and PabA, in
Aspergillus nidulans
. Our results demonstrate that ParA localizes to the septum site and that deletion of
parA
causes hyperseptation, while overexpression of
parA
abolishes septum formation; this suggests that ParA may function as a negative regulator of septation. In comparison, PabA displays a clear colocalization pattern with 4′,6-diamidino-2-phenylindole (DAPI)-stained nuclei, and deletion of
pabA
induces a remarkable delayed-septation phenotype. Both
parA
and
pabA
are required for hyphal growth, conidiation, and self-fertilization, likely to maintain normal levels of PP2A activity. Most interestingly,
parA
deletion is capable of suppressing septation defects in
pabA
mutants, suggesting that ParA counteracts PabA during the septation process. In contrast, double mutants of
parA
and
pabA
led to synthetic defects in colony growth, indicating that ParA functions synthetically with PabA during hyphal growth. Moreover, unlike the case for PP2A-Par1 and PP2A-Pab1 in yeast (which are negative regulators that inactivate the septation initiation network [SIN]), loss of ParA or PabA fails to suppress defects of temperature-sensitive mutants of the SEPH kinase of the SIN. Thus, our findings support the previously unrealized evidence that the B-family subunits of PP2A have comprehensive functions as partners of heterotrimeric enzyme complexes of PP2A, both spatially and temporally, in
A. nidulans
.
Inter-individual variation in midazolam clearance in children
Authors: Altamimi Mohammed I , Sammons Helen , Choonara Imti 
Published: October 2014

ObjectivesTo determine the extent of inter-individual variation in clearance of midazolam in children and establish which factors are responsible for this variation.MethodsA systematic literature review was performed to identify papers describing the clearance of midazolam in children. The following databases were searched: Medline, Embase, International Pharmaceutical Abstracts, CINAHL and Cochrane Library. From the papers, the range in plasma clearance and the coefficient of variation (CV) in plasma clearance were determined.Results25 articles were identified. Only 13 studies gave the full range of clearance values for individual patients. The CV was greater in critically ill patients (18%–170%) than non-critically ill patients (13%–54%). Inter-individual variation was a major problem in all age groups of critically ill patients. The CV was 72%–106% in preterm neonates, 18%–73% in term neonates, 31%–130% in infants, 21%–170% in children and 47%–150% in adolescents. The mean clearance was higher in children (1.1–16.7 mL/min/kg) than in neonates (0.78–2.5 mL/min/kg).ConclusionsLarge inter-individual variation was seen in midazolam clearance values in critically ill neonates, infants, children and adolescents.