bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serotonin neurones have anti‐convulsant effects and reduce seizure‐induced mortality
Authors: Buchanan Gordon F. , Murray Nicholas M. , Hajek Michael A. , Richerson George B. 
Published: August 2014

Key points
Sudden unexpected death in epilepsy is the leading cause of death in patients with refractory epilepsy.
Respiratory and cardiac impairment induced by a seizure have been identified as possible causes of seizure‐related death, but which is more important has been the subject of debate.
Serotonin has been linked to seizure control, but whether it is primarily anti‐convulsant or proconvulsant remains controversial.
In this study we induced seizures in mice with a genetic deletion of serotonin neurones and their phenotypically normal littermates while recording EEG, EMG, ECG and breathing, and assessed the effects of seizures on breathing, cardiac activity and survival
Serotonin and serotonin neurones are involved in setting the seizure threshold, regulating seizure severity and preventing mortality, and death in at least one seizure model is due to respiratory arrest, which can be prevented with selective serotonin reuptake inhibitor treatment or 5‐HT2A receptor activation.
AbstractSudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. Defects in central control of breathing are important contributors to the pathophysiology of SUDEP, and serotonin (5‐HT) system dysfunction may be involved. Here we examined the effect of 5‐HT neurone elimination or 5‐HT reduction on seizure risk and seizure‐induced mortality. Adult Lmx1bf/f/p mice, which lack >99% of 5‐HT neurones in the CNS, and littermate controls (Lmx1bf/f) were subjected to acute seizure induction by maximal electroshock (MES) or pilocarpine, variably including electroencephalography, electrocardiography, plethysmography, mechanical ventilation or pharmacological therapy. Lmx1bf/f/p mice had a lower seizure threshold and increased seizure‐induced mortality. Breathing ceased during most seizures without recovery, whereas cardiac activity persisted for up to 9 min before terminal arrest. The mortality rate of mice of both genotypes was reduced by mechanical ventilation during the seizure or 5‐HT2A receptor agonist pretreatment. The selective serotonin reuptake inhibitor citalopram reduced mortality of Lmx1bf/f but not of Lmx1bf/f/p mice. In C57BL/6N mice, reduction of 5‐HT synthesis with para‐chlorophenylalanine increased MES‐induced seizure severity but not mortality. We conclude that 5‐HT neurones raise seizure threshold and decrease seizure‐related mortality. Death ensued from respiratory failure, followed by terminal asystole. Given that SUDEP often occurs in association with generalised seizures, some mechanisms causing death in our model might be shared with those leading to SUDEP. This model may help determine the relationship between seizures, 5‐HT system dysfunction, breathing and death, which may lead to novel ways to prevent SUDEP.
Large environments reveal the statistical structure governing hippocampal representations
Authors: Rich P. Dylan , Liaw Hua-Peng , Lee Albert K. 
Published: August 2014

Nerve cells displaying extra large spacesRats use brain cells called “place” cells to figure out where they are. Richet al.used mazes or tracks many meters long—the size of rats' ranges in the wild—to investigate how rats represent a very large environment or extended experience in their brain. As novel environments became larger and larger, the rats' brains recruited new place cells. However, no matter how large the environment became, some cells always remained silent, perhaps as a reserve for other environments yet to be visited.Science, this issue p.814
Vibrio harveyi Adheres to and Penetrates Tissues of the European Abalone Haliotis tuberculata within the First Hours of Contact
Authors: Cardinaud Marion , Barbou Annaïck , Capitaine Carole , Bidault Adeline , Dujon Antoine Marie , Moraga Dario , Paillard Christine 
Published: August 2014

ABSTRACT

Vibrio harveyi
is a marine bacterial pathogen responsible for episodic epidemics generally associated with massive mortalities in many marine organisms, including the European abalone
Haliotis tuberculata
. The aim of this study was to identify the portal of entry and the dynamics of infection of
V. harveyi
in the European abalone. The results indicate that the duration of contact between
V. harveyi
and the European abalone influences the mortality rate and precocity. Immediately after contact, the epithelial and mucosal area situated between the gills and the hypobranchial gland was colonized by
V. harveyi
. Real-time PCR analyses and culture quantification of a green fluorescent protein-tagged strain of
V. harveyi
in abalone tissues revealed a high density of bacteria adhering to and then penetrating the whole gill-hypobranchial gland tissue after 1 h of contact.
V. harveyi
was also detected in the hemolymph of a significant number of European abalones after 3 h of contact. In conclusion, this article shows that a TaqMan real-time PCR assay is a powerful and useful technique for the detection of a marine pathogen such as
V. harveyi
in mollusk tissue and for the study of its infection dynamics. Thus, we have revealed that the adhesion and then the penetration of
V. harveyi
in European abalone organs begin in the first hours of contact. We also hypothesize that the portal of entry of
V. harveyi
in the European abalone is the area situated between the gills and the hypobranchial gland.
Bacteriophage ϕMAM1, a Viunalikevirus, Is a Broad-Host-Range, High-Efficiency Generalized Transducer That Infects Environmental and Clinical Isolates of the Enterobacterial Genera Serratia and Kluyvera
Authors: Matilla Miguel A. , Salmond George P. C. 
Published: August 2014

ABSTRACT

Members of the enterobacterial genus
Serratia
are ecologically widespread, and some strains are opportunistic human pathogens. Bacteriophage ϕMAM1 was isolated on
Serratia plymuthica
A153, a biocontrol rhizosphere strain that produces the potently bioactive antifungal and anticancer haterumalide oocydin A. The ϕMAM1 phage is a generalized transducing phage that infects multiple environmental and clinical isolates of
Serratia
spp. and a rhizosphere strain of
Kluyvera cryocrescens
. Electron microscopy allowed classification of ϕMAM1 in the family
Myoviridae
. Bacteriophage ϕMAM1 is virulent, uses capsular polysaccharides as a receptor, and can transduce chromosomal markers at frequencies of up to 7 × 10
−6
transductants per PFU. We also demonstrated transduction of the complete 77-kb oocydin A gene cluster and heterogeneric transduction of a plasmid carrying a type III toxin-antitoxin system. These results support the notion of the potential ecological importance of transducing phages in the acquisition of genes by horizontal gene transfer. Phylogenetic analyses grouped ϕMAM1 within the ViI-like bacteriophages, and genomic analyses revealed that the major differences between ϕMAM1 and other ViI-like phages arise in a region encoding the host recognition determinants. Our results predict that the wider genus of ViI-like phages could be efficient transducing phages, and this possibility has obvious implications for the ecology of horizontal gene transfer, bacterial functional genomics, and synthetic biology.
Two Novel Toxin Variants Revealed by Whole-Genome Sequencing of 175 Clostridium botulinum Type E Strains
Authors: Weedmark K. A. , Lambert D. L. , Mabon P. , Hayden K. L. , Urfano C. J. , Leclair D. , Van Domselaar G. , Austin J. W. , Corbett C. R. 
Published: August 2014

ABSTRACT

We sequenced 175
Clostridium botulinum
type E strains isolated from food, clinical, and environmental sources from northern Canada and analyzed their botulinum neurotoxin (
bont
) coding sequences (CDSs). In addition to
bont/E1
and
bont/E3
variant types, neurotoxin sequence analysis identified two novel BoNT type E variants termed E10 and E11. Strains producing type E10 were found along the eastern coastlines of Hudson Bay and the shores of Ungava Bay, while strains producing type E11 were only found in the Koksoak River region of Nunavik. Strains producing BoNT/E3 were widespread throughout northern Canada, with the exception of the coast of eastern Hudson Bay.
Efficient Simultaneous Saccharification and Fermentation of Inulin to 2,3-Butanediol by Thermophilic Bacillus licheniformis ATCC 14580
Authors: Li Lixiang , Chen Chao , Li Kun , Wang Yu , Gao Chao , Ma Cuiqing , Xu Ping 
Published: August 2014

ABSTRACT

2,3-Butanediol (2,3-BD) is an important starting material for the manufacture of bulk chemicals. For efficient and large-scale production of 2,3-BD through fermentation, low-cost substrates are required. One such substrate, inulin, is a polydisperse fructan found in a wide variety of plants. In this study, a levanase with high inulinase activity and high pH and temperature stability was identified in
Bacillus licheniformis
strain ATCC 14580.
B. licheniformis
strain ATCC 14580 was found to efficiently produce 2,3-BD from fructose at 50°C. Then, the levanase was used for simultaneous saccharification and fermentation (SSF) of inulin to 2,3-BD. A fed-batch SSF yielded 103.0 g/liter 2,3-BD in 30 h, with a high productivity of 3.4 g/liter · h. The results suggest that the SSF process developed with the thermophilic
B. licheniformis
strain used might be a promising alternative for efficient 2,3-BD production from the favorable substrate inulin.
Probing of Microbial Biofilm Communities for Coadhesion Partners
Authors: Ruhl Stefan , Eidt Andreas , Melzl Holger , Reischl Udo , Cisar John O. 
Published: August 2014

ABSTRACT

Investigations of interbacterial adhesion in dental plaque development are currently limited by the lack of a convenient assay to screen the multitude of species present in oral biofilms. To overcome this limitation, we developed a solid-phase fluorescence-based screening method to detect and identify coadhesive partner organisms in mixed-species biofilms. The applicability of this method was demonstrated using coaggregating strains of type 2 fimbrial adhesin-bearing actinomyces and receptor polysaccharide (RPS)-bearing streptococci. Specific adhesin/receptor-mediated coadhesion was detected by overlaying bacterial strains immobilized to a nitrocellulose membrane with a suspended, fluorescein-labeled bacterial partner strain. Coadhesion was comparable regardless of which cell type was labeled and which was immobilized. Formaldehyde treatment of bacteria, either in suspension or immobilized on nitrocellulose, abolished actinomyces type 2 fimbrial adhesin but not streptococcal RPS function, thereby providing a simple method for assigning complementary adhesins and glycan receptors to members of a coadhering pair. The method's broader applicability was shown by overlaying colony lifts of dental plaque biofilm cultures with fluorescein-labeled strains of type 2 fimbriated
Actinomyces naeslundii
or RPS-bearing
Streptococcus oralis
. Prominent coadhesion partners included not only streptococci and actinomyces, as expected, but also other bacteria not identified in previous coaggregation studies, such as adhesin- or receptor-bearing strains of
Neisseria pharyngitis
,
Rothia dentocariosa
, and
Kingella oralis
. The ability to comprehensively screen complex microbial communities for coadhesion partners of specific microorganisms opens a new approach in studies of dental plaque and other mixed-species biofilms.
Dynamics of Dual Infection with Campylobacter jejuni Strains in Chickens Reveals Distinct Strain-to-Strain Variation in Infection Ecology
Authors: Chaloner Gemma , Wigley Paul , Humphrey Suzanne , Kemmett Kirsty , Lacharme-Lora Lizeth , Humphrey Tom , Williams Nicola 
Published: August 2014

ABSTRACT

Although multiple genotypes of
Campylobacter jejuni
may be isolated from the same commercial broiler flock, little is known about the infection dynamics of different genotypes within individuals or their colonization sites within the gut. Single experimental infections with
C. jejuni
M1 (sequence type 137, clonal complex 45) and
C. jejuni
13126 (sequence type 21, clonal complex 21) revealed that 13126 colonized the ceca at significantly higher levels. The dissemination and colonization sites of the two
C. jejuni
strains then were examined in an experimental broiler flock. Two 33-day-old broiler chickens were infected with M1 and two with 13126, and 15 birds were left unchallenged. Cloacal swabs were taken postinfection to determine the colonization and shedding of each strain. By 2 days postinfection (dpi), 8/19 birds were shedding M1 whereas none were shedding 13126. At 8 dpi, all birds were shedding both strains. At 18 dpi, liver and cecal levels of each isolate were quantified, while in 10 birds they also were quantified at nine sites throughout the gastrointestinal (GI) tract. 13126 was found throughout the GI tract, while M1 was largely restricted to the ceca and colon. The livers of 7/19 birds were culture positive for 13126 only. These data show that 13126 has a distinctly different infection biology than strain M1. It showed slower colonization of the lower GI tract but was more invasive and able to colonize at a high level throughout the GI tract. The finding that
C. jejuni
strains have markedly different infection ecologies within the chicken has implications for control in the poultry industry and suggests that the contamination risk of edible tissues is dependent on the isolate involved.
Investigation of the Evolutionary Development of the Genus Bifidobacterium by Comparative Genomics
Authors: Lugli Gabriele Andrea , Milani Christian , Turroni Francesca , Duranti Sabrina , Ferrario Chiara , Viappiani Alice , Mancabelli Leonardo , Mangifesta Marta , Taminiau Bernard , Delcenserie Véronique , van Sinderen Douwe , Ventura Marco 
Published: August 2014

ABSTRACT

The
Bifidobacterium
genus currently encompasses 48 recognized taxa, which have been isolated from different ecosystems. However, the current phylogeny of bifidobacteria is hampered by the relative paucity of genotypic data. Here, we reassessed the taxonomy of this bacterial genus using genome-based approaches, which demonstrated that the previous taxonomic view of bifidobacteria contained several inconsistencies. In particular, high levels of genetic relatedness were shown to exist between particular
Bifidobacterium
taxa which would not justify their status as separate species. The results presented are here based on average nucleotide identity analysis involving the genome sequences for each type strain of the 48 bifidobacterial taxa, as well as phylogenetic comparative analysis of the predicted core genome of the
Bifidobacterium
genus. The results of this study demonstrate that the availability of complete genome sequences allows the reconstruction of a more robust bifidobacterial phylogeny than that obtained from a single gene-based sequence comparison, thus discouraging the assignment of a new or separate bifidobacterial taxon without such a genome-based validation.
Application of Long-Range and Binding Reverse Transcription-Quantitative PCR To Indicate the Viral Integrities of Noroviruses
Authors: Li Dan , De Keuckelaere Ann , Uyttendaele Mieke 
Published: August 2014

ABSTRACT

This study intends to establish and apply methods evaluating both viral capsid and genome integrities of human noroviruses (NoVs), which thus far remain nonculturable. Murine norovirus 1 (MNV-1) and human NoV GII.4 in phosphate-buffered saline suspensions were treated with heat, UV light, or ethanol and detected by reverse transcription-quantitative PCR (RT-qPCR), long-range RT-qPCR, binding RT-qPCR, and binding long-range RT-qPCR. For MNV-1 heated at 60°C for 2 and 30 min, limited reductions of genomic copies (<0.3-log) were obtained by RT-qPCR and long-range RT-qPCR, while the cell-binding pretreatments obtained higher reductions (>1.89-log reduction after 60°C for 30 min by binding long-range RT-qPCR). The human NoV GII.4 was found to be more heat resistant than MNV-1. For both MNV-1 and human NoV GII.4 after UV treatments of 20 and 200 mJ/cm
2
, no significant difference (
P
> 0.05) was observed between the dose-dependent reductions obtained by the four detection methodologies. Treatment of 70% ethanol for 1 min was shown to be more effective for inactivation of both MNV-1 and human NoV GII.4 than the heat and UV treatments used in this study. Subsequently, eight raspberry and four shellfish samples previously shown to be naturally contaminated with human NoVs by RT-qPCR (GI and GII; thus, 24 RT-qPCR signals) were subjected to comparison by this method. RT-qPCR, long-range RT-qPCR, binding RT-qPCR, and binding long-range RT-qPCR detected 20/24, 14/24, 24/24, and 23/24 positive signals, respectively, indicating the abundant presence of intact NoV particles.
Transcriptomic Responses of Phanerochaete chrysosporium to Oak Acetonic Extracts: Focus on a New Glutathione Transferase
Authors: Thuillier Anne , Chibani Kamel , Belli Gemma , Herrero Enrique , Dumarçay Stéphane , Gérardin Philippe , Kohler Annegret , Deroy Aurélie , Dhalleine Tiphaine , Bchini Raphael , Jacquot Jean-Pierre , Gelhaye Eric , Morel-Rouhier Mélanie 
Published: August 2014

ABSTRACT

The first steps of wood degradation by fungi lead to the release of toxic compounds known as extractives. To better understand how lignolytic fungi cope with the toxicity of these molecules, a transcriptomic analysis of
Phanerochaete chrysosporium
genes was performed in the presence of oak acetonic extracts. It reveals that in complement to the extracellular machinery of degradation, intracellular antioxidant and detoxification systems contribute to the lignolytic capabilities of fungi, presumably by preventing cellular damages and maintaining fungal health. Focusing on these systems, a glutathione transferase (
P. chrysosporium
GTT2.1 [PcGTT2.1]) has been selected for functional characterization. This enzyme, not characterized so far in basidiomycetes, has been classified first as a GTT2 compared to the
Saccharomyces cerevisiae
isoform. However, a deeper analysis shows that the GTT2.1 isoform has evolved functionally to reduce lipid peroxidation by recognizing high-molecular-weight peroxides as substrates. Moreover, the GTT2.1 gene has been lost in some non-wood-decay fungi. This example suggests that the intracellular detoxification system evolved concomitantly with the extracellular ligninolytic machinery in relation to the capacity of fungi to degrade wood.
Discovery of Multiple Modified F
430
Coenzymes in Methanogens and Anaerobic Methanotrophic Archaea Suggests Possible New Roles for F
430
in Nature
Authors: Allen Kylie D. , Wegener Gunter , White Robert H. 
Published: August 2014

ABSTRACT

Methane is a potent greenhouse gas that is generated and consumed in anaerobic environments through the energy metabolism of methanogens and
an
aerobic
me
thanotrophic archaea (ANME), respectively. Coenzyme F
430
is essential for methanogenesis, and a structural variant of F
430
, 17
2
-methylthio-F
430
(F
430
-2), is found in ANME and is presumably essential for the anaerobic oxidation of methane. Here we use liquid chromatography–high-resolution mass spectrometry to identify several new structural variants of F
430
in the cell extracts of selected methanogens and ANME.
Methanocaldococcus jannaschii
and
Methanococcus maripaludis
contain an F
430
variant (denoted F
430
-3) that has an M
+
of 1,009.2781. This mass increase of 103.9913 over that of F
430
corresponds to C
3
H
4
O
2
S and is consistent with the addition of a 3-mercaptopropionate moiety bound as a thioether followed by a cyclization. The UV absorbance spectrum of F
430
-3 was different from that of F
430
and instead matched that of an F
430
derivative where the 17
3
keto moiety had been reduced. This is the first report of a modified F
430
in methanogens. In a search for F
430
-2 and F
430
-3 in other methanogens and ANME, we have identified a total of nine modified F
430
structures. One of these compounds may be an abiotic oxidative product of F
430
, but the others represent naturally modified versions of F
430
. This work indicates that F
430
-related molecules have additional functions in nature and will inspire further research to determine the biochemical role(s) of these variants and the pathways involved in their biosynthesis.
Collection and Characterization of Samples for Establishment of a Serum Repository for Lyme Disease Diagnostic Test Development and Evaluation
Authors: Molins Claudia R. , Sexton Christopher , Young John W. , Ashton Laura V. , Pappert Ryan , Beard Charles B. , Schriefer Martin E. 
Published: August 2014

ABSTRACT
Serological assays and a two-tiered test algorithm are recommended for laboratory confirmation of Lyme disease. In the United States, the sensitivity of two-tiered testing using commercially available serology-based assays is dependent on the stage of infection and ranges from 30% in the early localized disease stage to near 100% in late-stage disease. Other variables, including subjectivity in reading Western blots, compliance with two-tiered recommendations, use of different first- and second-tier test combinations, and use of different test samples, all contribute to variation in two-tiered test performance. The availability and use of sample sets from well-characterized Lyme disease patients and controls are needed to better assess the performance of existing tests and for development of improved assays. To address this need, the Centers for Disease Control and Prevention and the National Institutes of Health prospectively collected sera from patients at all stages of Lyme disease, as well as healthy donors and patients with look-alike diseases. Patients and healthy controls were recruited using strict inclusion and exclusion criteria. Samples from all included patients were retrospectively characterized by two-tiered testing. The results from two-tiered testing corroborated the need for novel and improved diagnostics, particularly for laboratory diagnosis of earlier stages of infection. Furthermore, the two-tiered results provide a baseline with samples from well-characterized patients that can be used in comparing the sensitivity and specificity of novel diagnostics. Panels of sera and accompanying clinical and laboratory testing results are now available to Lyme disease serological test users and researchers developing novel tests.