bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Cryopreservation on the Meiotic Spindle, Cortical Granule Distribution and Development of Rabbit Oocytes
Authors: Jiménez‐Trigos E , Naturil‐Alfonso C , Vicente JS , Marco‐Jiménez F 
Published: October 2011

ContentsAlthough much progress has been made in oocyte cryopreservation since 1971, live offspring have only been obtained in a few species and in rabbits. The aim of our study was to evaluate the effect of vitrification and slow freezing on the meiotic spindle, cortical granule (CG) distribution and their developmental competence. Oocytes were vitrified in 16.84% ethylene glycol, 12.86% formamide, 22.3% dimethyl sulphoxide, 7% PVP and 1% of synthetic ice blockers using Cryotop as device or slow freezing in 1.5 m PROH and 0.2 m sucrose in 0.25 ml sterile French mini straws. Meiotic spindle and CG distribution were assessed using a confocal laser‐scanning microscope. To determine oocyte competence, in vitro development of oocytes from each cryopreservation procedure was assessed using parthenogenesis activation. Our data showed that oocytes were significantly affected by both cryopreservation procedures. In particular, meiotic spindle organization was dramatically altered after cryopreservation. Oocytes with peripheral CG distribution have a better chance of survival in cryopreservation after slow‐freezing procedures compared to vitrification. In addition, slow freezing of oocytes led to higher cleavage and blastocyst rates compared to vitrification. Our data showed that, in rabbits, structural alterations are more evident in vitrified oocytes than in slow‐frozen oocytes, probably as a consequence of sensitivity to high levels of cryoprotectants. Slow‐freezing method is currently the recommended option for rabbit oocyte cryopreservation.
Making Predictions from Complex Longitudinal Data, with Application to Planning Monitoring Intervals in a National Screening Programme
Authors: Sweeting M. J. , Thompson S. G. 
Published: October 2011

SummaryWhen biological or physiological variables change over time, we are often interested in making predictions either of future measurements or of the time taken to reach some threshold value. On the basis of longitudinal data for multiple individuals, we develop Bayesian hierarchical models for making these predictions together with their associated uncertainty. Particular aspects addressed, which include some novel components, are handling curvature in individuals’ trends over time, making predictions for both underlying and measured levels, making predictions from a single baseline measurement, making predictions from a series of measurements, allowing flexibility in the error and random-effects distributions, and including covariates. In the context of data on the expansion of abdominal aortic aneurysms over time, where reaching a certain threshold leads to referral for surgery, we discuss the practical application of these models to the planning of monitoring intervals in a national screening programme. Prediction of the time to reach a threshold was too imprecise to be practically useful, and we focus instead on limiting the probability of exceeding the threshold after given time intervals. Although more complex models can be shown to fit the data better, we find that relatively simple models seem to be adequate for planning monitoring intervals.
Hair and nail water‐holding capability measurements by using condenser‐TEWL method
Authors: Xiao P. , Cui Y. , Ciortea L. I. , Berg E. P. , Imhof R. E. 
Published: October 2011

SynopsisWe have developed a new method for studying human hair and nail water‐holding capabilities by using the condenser‐chamber trans‐epidermal water loss (TEWL) method. Healthy hair and nail always contain certain amount of water, and they will lose this water to the environment naturally through evaporations. We monitored this desorption process by continuously measuring the water vapour flux density from hair and nail using the condenser‐TEWL method, which is a condenser‐based closed‐chamber TEWL technology that is particularly suitable for this kind of measurements. We have also develop mathematical models for modelling the hair and nail desorption process. By fitting the normalized hair and nail desorption data with the mathematical models, we can get the water diffusion coefficient information, which can then be related to the water‐holding capabilities of the hair and nail samples.
Ontogenetic modifications of neuronal excitability during brain maturation: Developmental changes of neurotransmitter receptors
Authors: Aronica Eleonora , Iyer Anand , Zurolo Emanuele , Gorter Jan A. 
Published: October 2011

SummaryThe development of the human brain depends on a precisely orchestrated cascade of events, including proliferation, migration and maturation of neural progenitor cells. Different mechanisms coordinate these stages to reach a normal structural organization, producing appropriate excitatory and inhibitory networks. Here, we will briefly review the developmental changes of glutamate (Glu) and γ‐aminobutyric acid (GABA) receptors, with particular attention to the development of the human brain. We will also briefly discuss recent evidence on the involvement of the endocannabinoid signaling in the regulation of neuronal excitability during early brain development..
The effect of boric acid on bacterial culture of canine and feline urine
Authors: Rowlands M. , Blackwood L. , Mas A. , Cripps P. , Crompton C. , Burrow R. 
Published: October 2011

Objective: To identify the optimal method of submission of canine and feline urine for bacterial culture.Methods: Cystocentesis samples from 250 animals (200 dogs, 50 cats) suspected of having urinary tract infections were collected. The reference aliquot, without preservative, was processed on site within 2 hours. Two further aliquots (one without preservative, one with boric acid) were stored at room temperature for up to 7 hours and then posted by guaranteed next day delivery to a commercial laboratory for analysis.Results: Forty‐seven of the samples were positive on culture in the reference test. There was no significant difference between reference test results and those of samples posted without preservative (P=0·39), but samples posted in boric acid were significantly less likely to give a positive result (P=0·01). Samples posted without preservative had a sensitivity of 82% and a specificity of 98%; for boric acid, sensitivity was 73% and specificity 99%.Clinical Significance: Postal urine samples should be submitted to the laboratory in a plain sterile tube.
High Ethanol Titers from Cellulose by Using Metabolically Engineered Thermophilic, Anaerobic Microbes
Authors: Argyros D. Aaron , Tripathi Shital A. , Barrett Trisha F. , Rogers Stephen R. , Feinberg Lawrence F. , Olson Daniel G. , Foden Justine M. , Miller Bethany B. , Lynd Lee R. , Hogsett David A. , Caiazza Nicky C. 
Published: October 2011

ABSTRACT

This work describes novel genetic tools for use in
Clostridium thermocellum
that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native
C. thermocellum hpt
gene and the
Thermoanaerobacterium saccharolyticum tdk
gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta). The Δ
ldh
Δ
pta
mutant was evolved for 2,000 h, resulting in a stable strain with 40:1 ethanol selectivity and a 4.2-fold increase in ethanol yield over the wild-type strain. Ethanol production from cellulose was investigated with an engineered coculture of organic acid-deficient engineered strains of both
C. thermocellum
and
T. saccharolyticum
. Fermentation of 92 g/liter Avicel by this coculture resulted in 38 g/liter ethanol, with acetic and lactic acids below detection limits, in 146 h. These results demonstrate that ethanol production by thermophilic, cellulolytic microbes is amenable to substantial improvement by metabolic engineering.
Characterization and Quantitation of a Novel β-Lactamase Gene Found in a Wastewater Treatment Facility and the Surrounding Coastal Ecosystem
Authors: Uyaguari Miguel I. , Fichot Erin B. , Scott Geoffrey I. , Norman R. Sean 
Published: October 2011

ABSTRACT

Wastewater treatment plants (WWTPs) are engineered structures that collect, concentrate, and treat human waste, ultimately releasing treated wastewater into local environments. While WWTPs efficiently remove most biosolids, it has been shown that many antibiotics and antibiotic-resistant bacteria can survive the treatment process. To determine how WWTPs influence the concentration and dissemination of antibiotic-resistant genes into the environment, a functional metagenomic approach was used to identify a novel antibiotic resistance gene within a WWTP, and quantitative PCR (qPCR) was used to determine gene copy numbers within the facility and the local coastal ecosystem. From the WWTP metagenomic library, the fosmid insert contained in one highly resistant clone (MIC, ∼416 μg ml
−1
ampicillin) was sequenced and annotated, revealing 33 putative genes, including a 927-bp gene that is 42% identical to a functionally characterized β-lactamase from
Staphylococcus aureus
PC1. Isolation and subcloning of this gene, referred to as
bla
M-1
, conferred ampicillin resistance to its
Escherichia coli
host. When normalized to volume, qPCR showed increased concentrations of
bla
M-1
during initial treatment stages but 2-fold-decreased concentrations during the final treatment stage. The concentration ng
−1
DNA increased throughout the WWTP process from influent to effluent, suggesting that
bla
M-1
makes up a significant proportion of the overall genetic material being released into the coastal ecosystem. Average discharge was estimated to be 3.9 ï¿½ 10
14
copies of the
bla
M-1
gene released daily into this coastal ecosystem. Furthermore, the gene was observed in all sampled coastal water and sediment samples surrounding the facility. Our results suggest that WWTPs may be a pathway for the dissemination of novel antibiotic resistance genes into the environment.
Genome and Proteome of Campylobacter jejuni Bacteriophage NCTC 12673
Authors: Kropinski Andrew M. , Arutyunov Denis , Foss Mary , Cunningham Anna , Ding Wen , Singh Amit , Pavlov Andrey R. , Henry Matthew , Evoy Stephane , Kelly John , Szymanski Christine M. 
Published: October 2011

ABSTRACT

Campylobacter jejuni
continues to be the leading cause of bacterial food-borne illness worldwide, so improvements to current methods used for bacterial detection and disease prevention are needed. We describe here the genome and proteome of
C. jejuni
bacteriophage NCTC 12673 and the exploitation of its receptor-binding protein for specific bacterial detection. Remarkably, the 135-kb
Myoviridae
genome of NCTC 12673 differs greatly from any other proteobacterial phage genome described (including
C. jejuni
phages CP220 and CPt10) and instead shows closest homology to the cyanobacterial T4-related myophages. The phage genome contains 172 putative open reading frames, including 12 homing endonucleases, no visible means of packaging, and a putative
trans
-splicing intein. The phage DNA appears to be strongly associated with a protein that interfered with PCR amplification and estimation of the phage genome mass by pulsed-field gel electrophoresis. Identification and analyses of the receptor-binding protein (Gp48) revealed features common to the
Salmonella enterica
P22 phage tailspike protein, including the ability to specifically recognize a host organism. Bacteriophage receptor-binding proteins may offer promising alternatives for use in pathogen detection platforms.
Identification of Fecal Input Sites in Spring Water by Selection and Genotyping of Multiresistant Escherichia coli
Authors: Wicki Melanie , Karabulut Fatma , Auckenthaler Adrian , Felleisen Richard , Tanner Marcel , Baumgartner Andreas 
Published: October 2011

ABSTRACT

The localization of fecal input sites is important for water quality management. For this purpose, we have developed a new approach based on a three-step procedure, including a preparatory phase, the screening of multiresistant bacteria using selective agar plates, and a typing phase where selected
Escherichia coli
isolates are characterized by antibiotic resistance profiles and molecular fingerprinting techniques (pulsed-field gel electrophoresis [PFGE]). These two well-known source tracking methods were combined in order to reduce cost and effort. This approach was successfully applied under field conditions in a study area located in the north-western part of Switzerland.
E. coli
isolates from spring water and surface water samples collected in this area were screened with selective agar plates. In this way, 21 different groups, each consisting of strains with the same pattern of antibiotic resistance, were found. Of these, four groups were further analyzed using PFGE. Strains with identical PFGE profiles were detected repeatedly, demonstrating the suitability of this method for the localization of fecal input sites over an extended period of time. Identical PFGE patterns of strains detected in water from two different springs were also found in the stream flowing through the study area. These results demonstrated the applicability of the new approach for the examination of incidents of fecal contamination in drinking water. The advantages of the described approach over genotyping methods currently being used to identify sources of fecal contaminants are a reduction in time, costs, and the effort required. Identical isolates could be identified without the construction of large libraries.
Cotransmission of Divergent Relapsing Fever Spirochetes by Artificially Infected Ornithodoros hermsi
Authors: Policastro Paul F. , Raffel Sandra J. , Schwan Tom G. 
Published: October 2011

ABSTRACT

The soft tick
Ornithodoros hermsi
, which ranges in specific arboreal zones of western North America, acts as a vector for the relapsing fever spirochete
Borrelia hermsii
. Two genomic groups (genomic group I [GGI] and GGII) of
B. hermsii
are differentiated by multilocus sequence typing yet are codistributed in much of the vector's range. To test whether the tick vector can be infected via immersion, noninfected, colony-derived
O. hermsi
larvae were exposed to reduced-humidity conditions before immersion in culture suspensions of several GGI and GGII isolates. We tested for spirochetes in ticks by immunofluorescence microscopy and in mouse blood by quantitative PCR of the
vtp
locus to differentiate spirochete genotypes. The immersed larval ticks were capable of spirochete transmission to mice at the first nymphal feeding. Tick infection with mixed cultures of isolates DAH (
vtp-6
) (GGI) and MTW-2 (
vtp-5
) (GGII) resulted in ticks that caused spirochetemias in mice consisting of MTW-2 or both DAH and MTW-2. These findings show that this soft tick species can acquire
B. hermsii
by immersion in spirochete suspensions, that GGI and GGII isolates can coinfect the tick vector by this method, and that these spirochetes can be cotransmitted to a rodent host.
Bacterial Communities of Two Parthenogenetic Aphid Species Cocolonizing Two Host Plants across the Hawaiian Islands
Authors: Jones Ryan T. , Bressan Alberto , Greenwell April M. , Fierer Noah 
Published: October 2011

ABSTRACT

Aphids (Hemiptera: Aphididae) have been the focus of several studies with respect to their interactions with inherited symbionts, but bacterial communities of most aphid species are still poorly characterized. In this research, we used bar-coded pyrosequencing to characterize bacterial communities in aphids. Specifically, we examined the diversity of bacteria in two obligately parthenogenetic aphid species (the melon aphid,
Aphis gossypii
, and the cardamom aphid,
Pentalonia caladii
) cocolonizing two plant species (taro,
Colocasia esculenta
, and ginger,
Alpinia purpurata
) across four Hawaiian Islands (Hawaii, Kauai, Maui, and Oahu). Results from this study revealed that heritable symbionts dominated the bacterial communities for both aphid species. The bacterial communities differed significantly between the two species, and
A. gossypii
harbored a more diverse bacterial community than
P. caladii
. The bacterial communities also differed across aphid populations sampled from the different islands; however, communities did not differ between aphids collected from the two host plants.
Combined Effect of Improved Cell Yield and Increased Specific Productivity Enhances Recombinant Enzyme Production in Genome-Reduced Bacillus subtilis Strain MGB874
Authors: Manabe Kenji , Kageyama Yasushi , Morimoto Takuya , Ozawa Tadahiro , Sawada Kazuhisa , Endo Keiji , Tohata Masatoshi , Ara Katsutoshi , Ozaki Katsuya , Ogasawara Naotake 
Published: October 2011

ABSTRACTGenome reduction strategies to create genetically improved cellular biosynthesis machineries for proteins and other products have been pursued by use of a wide range of bacteria. We reported previously that the novelBacillus subtilisstrain MGB874, which was derived from strain 168 and has a total genomic deletion of 874 kb (20.7%), exhibits enhanced production of recombinant enzymes. However, it was not clear how the genomic reduction resulted in elevated enzyme production. Here we report that deletion of therocDEF-rocRregion, which is involved in arginine degradation, contributes to enhanced enzyme production in strain MGB874. Deletion of therocDEF-rocRregion caused drastic changes in glutamate metabolism, leading to improved cell yields with maintenance of enzyme productivity. Notably, the specific enzyme productivity was higher in the reduced-genome strain, with or without therocDEF-rocRregion, than in wild-type strain 168. The high specific productivity in strain MGB874 is likely attributable to the higher expression levels of the target gene resulting from an increased promoter activity and plasmid copy number. Thus, the combined effects of the improved cell yield by deletion of therocDEF-rocRregion and the increased specific productivity by deletion of another gene(s) or the genomic reduction itself enhanced the production of recombinant enzymes in MGB874. Our findings represent a good starting point for the further improvement ofB. subtilisreduced-genome strains as cell factories for the production of heterologous enzymes.
Survival and Heat Resistance of Salmonella enterica and Escherichia coli O157:H7 in Peanut Butter
Authors: He Yingshu , Guo Dongjing , Yang Jingyun , Tortorello Mary Lou , Zhang Wei 
Published: October 2011

ABSTRACT

Significant differences (
P
< 0.05) were found between the survival rates of
Salmonella enterica
and
Escherichia coli
O157:H7 in peanut butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment.
Global Analysis of Serine-Threonine Protein Kinase Genes in Neurospora crassa
Authors: Park Gyungsoon , Servin Jacqueline A. , Turner Gloria E. , Altamirano Lorena , Colot Hildur V. , Collopy Patrick , Litvinkova Liubov , Li Liande , Jones Carol A. , Diala Fitz-Gerald , Dunlap Jay C. , Borkovich Katherine A. 
Published: October 2011

ABSTRACT

Serine/threonine (S/T) protein kinases are crucial components of diverse signaling pathways in eukaryotes, including the model filamentous fungus
Neurospora crassa
. In order to assess the importance of S/T kinases to
Neurospora
biology, we embarked on a global analysis of 86 S/T kinase genes in
Neurospora
. We were able to isolate viable mutants for 77 of the 86 kinase genes. Of these, 57% exhibited at least one growth or developmental phenotype, with a relatively large fraction (40%) possessing a defect in more than one trait. S/T kinase knockouts were subjected to chemical screening using a panel of eight chemical treatments, with 25 mutants exhibiting sensitivity or resistance to at least one chemical. This brought the total percentage of S/T mutants with phenotypes in our study to 71%. Mutants lacking
apg-1
, an S/T kinase required for autophagy in other organisms, possessed the greatest number of phenotypes, with defects in asexual and sexual growth and development and in altered sensitivity to five chemical treatments. We showed that NCU02245/
stk-19
is required for chemotropic interactions between female and male cells during mating. Finally, we demonstrated allelism between the S/T kinase gene NCU00406 and
velvet
(
vel
), encoding a p21-activated protein kinase (PAK) gene important for asexual and sexual growth and development in
Neurospora
.
Functional Analysis of the Exported Type IV HSP40 Protein PfGECO in Plasmodium falciparum Gametocytes
Authors: Morahan Belinda J. , Strobel Carolyn , Hasan Uzma , Czesny Beata , Mantel Pierre-Yves , Marti Matthias , Eksi Saliha , Williamson Kim C. 
Published: October 2011

ABSTRACT

During
Plasmodium falciparum
infection, host red blood cell (RBC) remodeling is required for the parasite's survival. Such modifications are mediated by the export of parasite proteins into the RBC that alter the architecture of the RBC membrane and enable cytoadherence. It is probable that some exported proteins also play a protective role against the host defense response. This may be of particular importance for the gametocyte stage of the life cycle that is responsible for malaria transmission, since the gametocyte remains in contact with blood as it proceeds through five morphological stages (I to V) during its 12-day maturation. Using microarray analysis, we identified several genes with encoded secretory or export sequences that were differentially expressed during early gametocytogenesis. One of these,
PfGECO
, encodes a predicted type IV heat shock protein 40 (HSP40) that we show is expressed in gametocyte stages I to IV and is exported to the RBC cytoplasm. HSPs are traditionally induced under stressful conditions to maintain homeostasis, but
PfGECO
expression was not increased upon heat shock, suggesting an alternate function. Targeted disruption of
PfGECO
indicated that the gene is not essential for gametocytogenesis
in vitro
, and quantitative reverse transcriptase PCR (RT-PCR) showed that there was no compensatory expression of the other type IV HSP40 genes. Although
P. falciparum
HSP40 members are implicated in the trafficking of proteins to the RBC surface, removal of PfGECO did not affect the targeting of other exported gametocyte proteins. This work has expanded the repertoire of known gametocyte-exported proteins to include a type IV HSP40, PfGECO.
Mitosomes in Trophozoites and Cysts of the Reptilian Parasite Entamoeba invadens
Authors: Siegesmund Maria A. , Hehl Adrian B. , van der Giezen Mark 
Published: October 2011

ABSTRACT

Heat shock protein genes led to the discovery of mitosomes in
Entamoeba histolytica
, but mitosomes have not been described for any other
Entamoeba
species, nor have they been identified in the cyst stage. Here, we show that the distantly related reptilian pathogen
Entamoeba invadens
contains mitosomes, in both trophozoites and cysts, suggesting all
Entamoeba
species contain these organelles.