bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of UV-B Radiation and Periodic Desiccation on the Morphogenesis of the Edible Terrestrial Cyanobacterium Nostoc flagelliforme
Authors: Feng Yan-Na , Zhang Zhong-Chun , Feng Jun-Li , Qiu Bao-Sheng
Published: August 2012

The terrestrial cyanobacterium
Nostoc flagelliforme
Berk. et M. A. Curtis has been a popular food and herbal ingredient for hundreds of years. To meet great market demand and protect the local ecosystem, for decades researchers have tried to cultivate
N. flagelliforme
but have failed to get macroscopic filamentous thalli. In this study, single trichomes with 50 to 200 vegetative cells were induced from free-living cells by low light and used to investigate the morphogenesis of
N. flagelliforme
under low UV-B radiation and periodic desiccation. Low-fluence-rate UV-B (0.1 W m
−2
) did not inhibit trichome growth; however, it significantly increased the synthesis of extracellular polysaccharides and mycosporine-like amino acids and promoted sheath formation outside the trichomes. Under low UV-B radiation, single trichomes developed into filamentous thalli more than 1 cm long after 28 days of cultivation, most of which grew separately in liquid BG11 medium. With periodic desiccation treatment, the single trichomes formed flat or banded thalli that grew up to 2 cm long after 3 months on solid BG11 medium. When trichomes were cultivated on solid BG11 medium with alternate treatments of low UV-B and periodic desiccation, dark and scraggly filamentous thalli that grew up to about 3 cm in length after 40 days were obtained. In addition, the cultivation of trichomes on nitrogen-deficient solid BG11 medium (BG11
0
) suggested that nitrogen availability could affect the color and lubricity of newly developed thalli. This study provides promising techniques for artificial cultivation of
N. flagelliforme
in the future.
Influence of Seasonal and Geochemical Changes on the Geomicrobiology of an Iron Carbonate Mineral Water Spring
Authors: Hegler Florian , Lösekann-Behrens Tina , Hanselmann Kurt , Behrens Sebastian , Kappler Andreas
Published: August 2012

Fuschna Spring in the Swiss Alps (Engadin region) is a bicarbonate iron(II)-rich, pH-neutral mineral water spring that is dominated visually by dark green microbial mats at the side of the flow channel and orange iron(III) (oxyhydr)oxides in the flow channel. Gradients of O
2
, dissolved iron(II), and bicarbonate establish in the water. Our goals were to identify the dominating biogeochemical processes and to determine to which extent changing geochemical conditions along the flow path and seasonal changes influence mineral identity, crystallinity, and microbial diversity. Geochemical analysis showed microoxic water at the spring outlet which became fully oxygenated within 2.3 m downstream. X-ray diffraction and Mössbauer spectroscopy revealed calcite (CaCO
3
) and ferrihydrite [Fe(OH)
3
] to be the dominant minerals which increased in crystallinity with increasing distance from the spring outlet. Denaturing gradient gel electrophoresis banding pattern cluster analysis revealed that the microbial community composition shifted mainly with seasons and to a lesser extent along the flow path. 16S rRNA gene sequence analysis showed that microbial communities differ between the flow channel and the flanking microbial mat. Microbial community analysis in combination with most-probable-number analyses and quantitative PCR (qPCR) showed that the mat was dominated by cyanobacteria and the channel was dominated by microaerophilic Fe(II) oxidizers (1.97 × 10
7
± 4.36 × 10
6
16S rRNA gene copies g
−1
using
Gallionella
-specific qPCR primers), while high numbers of Fe(III) reducers (10
9
cells/g) were identified in both the mat and the flow channel. Phototrophic and nitrate-reducing Fe(II) oxidizers were present as well, although in lower numbers (10
3
to 10
4
cells/g). In summary, our data suggest that mainly seasonal changes caused microbial community shifts, while geochemical gradients along the flow path influenced mineral crystallinity.
A Wide Variety of Clostridium perfringens Type A Food-Borne Isolates That Carry a ChromosomalcpeGene Belong to One Multilocus Sequence Typing Cluster
Authors: Xiao Yinghua , Wagendorp Arjen , Moezelaar Roy , Abee Tjakko , Wells-Bennik Marjon H. J.
Published: August 2012

Of 98 suspected food-borneClostridium perfringensisolates obtained from a nationwide survey by the Food and Consumer Product Safety Authority in The Netherlands, 59 strains were identified asC. perfringenstype A. Using PCR-based techniques, thecpegene encoding enterotoxin was detected in eight isolates, showing a chromosomal location for seven isolates and a plasmid location for one isolate. Further characterization of these strains by using (GTG)5fingerprint repetitive sequence-based PCR analysis distinguishedC. perfringensfrom other sulfite-reducing clostridia but did not allow for differentiation between various types ofC. perfringensstrains. To characterize theC. perfringensstrains further, multilocus sequence typing (MLST) analysis was performed on eight housekeeping genes of both enterotoxic and non-cpeisolates, and the data were combined with a previous global survey covering strains associated with food poisoning, gas gangrene, and isolates from food or healthy individuals. This revealed that the chromosomalcpestrains (food strains and isolates from food poisoning cases) belong to a distinct cluster that is significantly distant from all the othercpeplasmid-carrying andcpe-negative strains. These results suggest that different groups ofC. perfringenshave undergone niche specialization and that a distinct group of food isolates has specific core genome sequences. Such findings have epidemiological and evolutionary significance. Better understanding of the origin and reservoir of enterotoxicC. perfringensmay allow for improved control of this organism in foods.
Comparison of the Multiple-Sample Means with Composite Sample Results for Fecal Indicator Bacteria by Quantitative PCR and Culture
Authors: Converse Reagan R. , Wymer Larry J. , Dufour Alfred P. , Wade Timothy J.
Published: August 2012

Few studies have addressed the efficacy of composite sampling for measuring indicator bacteria by quantitative PCR (qPCR). We compared results from composited samples with multiple-sample means for culture- and qPCR-based water quality monitoring. Results from composited samples for both methods were similarly correlated to multiple-sample means and predicted criteria exceedances equally.
The Type 3 Protein Secretion System of Cupriavidus taiwanensis Strain LMG19424 Compromises Symbiosis with Leucaena leucocephala
Authors: Saad Maged M. , Crèvecoeur Michèle , Masson-Boivin Catherine , Perret Xavier
Published: August 2012

Cupriavidus taiwanensis
forms proficient symbioses with a few
Mimosa
species. Inactivation of a type III protein secretion system (T3SS) had no effect on
Mimosa pudica
but allowed
C. taiwanensis
to establish chronic infections and fix nitrogen in
Leucaena leucocephala
. Unlike what was observed for other rhizobia, glutamate rather than plant flavonoids mediated transcriptional activation of this atypical T3SS.
Characterization of a Novel Subgroup of Extracellular Medium-Chain-Length Polyhydroxyalkanoate Depolymerases from Actinobacteria
Authors: Gangoiti Joana , Santos Marta , Prieto María Auxiliadora , de la Mata Isabel , Serra Juan L. , Llama María J.
Published: August 2012

Nineteen medium-chain-length (mcl) poly(3-hydroxyalkanoate) (PHA)-degrading microorganisms were isolated from natural sources. From them, seven Gram-positive and three Gram-negative bacteria were identified. The ability of these microorganisms to hydrolyze other biodegradable plastics, such as short-chain-length (scl) PHA, poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), and poly(
l
-lactide) (PLA), has been studied. On the basis of the great ability to degrade different polyesters,
Streptomyces roseolus
SL3 was selected, and its extracellular depolymerase was biochemically characterized. The enzyme consisted of one polypeptide chain of 28 kDa with a pI value of 5.2. Its maximum activity was observed at pH 9.5 with chromogenic substrates. The purified enzyme hydrolyzed mcl PHA and PCL but not scl PHA, PES, and PLA. Moreover, the mcl PHA depolymerase can hydrolyze various substrates for esterases, such as tributyrin and
p
-nitrophenyl (
p
NP)-alkanoates, with its maximum activity being measured with
p
NP-octanoate. Interestingly, when poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate [11%]) was used as the substrate, the main hydrolysis product was the monomer (
R
)-3-hydroxyoctanoate. In addition, the genes of several
Actinobacteria
strains, including
S. roseolus
SL3, were identified on the basis of the peptide
de novo
sequencing of the
Streptomyces venezuelae
SO1 mcl PHA depolymerase by tandem mass spectrometry. These enzymes did not show significant similarity to mcl PHA depolymerases characterized previously. Our results suggest that these distinct enzymes might represent a new subgroup of mcl PHA depolymerases.
Synergistic Activation of the Pathogenicity-Related Proline Iminopeptidase Gene in Xanthomonas campestris pv. campestris by HrpX and a LuxR Homolog
Authors: Zhang Jingxi , Kan Jinhong , Zhang Jieqiong , Guo Ping , Chen Xiaoying , Fang Rongxiang , Jia Yantao
Published: August 2012

Xanthomonas campestris
pv. campestris strain 8004 contains an orphan quorum-sensing (QS) locus,
xccR
-
pip

Xcc

, in which the proline iminopeptidase (
pip

Xcc

) gene (where “
Xcc
” indicates that the
pip
gene is from
X. campestris
pv. campestris) is positively regulated by the LuxR homologue XccR by binding to the
luxXc
box of the
pip

Xcc

promoter. The disruption of
pip

Xcc

significantly attenuated the virulence of
X. campestris
pv. campestris. An imperfect plant-inducible promoter (PIP) box is located in the upstream region of the
pip

Xcc

promoter, which is the putative binding site of the transcriptional activator HrpX. To explore whether the expression of the
pip

Xcc

gene is regulated by HrpX, the expression level of a
pip

Xcc

promoter-
gusA
fusion gene was assayed in an
hrpX
disruption mutant. The results showed that the lack of HrpX dramatically decreased the β-glucuronidase (GUS) activity. Further analyses using an electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP)-PCR indicated that the imperfect PIP box in
X. campestris
pv. campestris is specifically bound to HrpX. These data demonstrated that the
pip

Xcc

gene belongs to the hrp regulon and that the imperfect PIP box of the
pip

Xcc

promoter could be a
cis
element for the HrpX protein. We further showed in a pulldown assay that XccR can bind HrpX, suggesting that these two regulatory proteins coactivate the virulence factor by binding to the different
cis
elements of the
pip

Xcc

gene and adapt to the host environment during
X. campestris
pv. campestris infection.
Hal Is a Bacillus anthracis Heme Acquisition Protein
Authors: Balderas Miriam A. , Nobles Christopher L. , Honsa Erin S. , Alicki Embriette R. , Maresso Anthony W.
Published: August 2012

The metal iron is a limiting nutrient for bacteria during infection.Bacillus anthracis, the causative agent of anthrax and a potential weapon of bioterrorism, grows rapidly in mammalian hosts, which suggests that it efficiently attains iron during infection. Recent studies have uncovered both heme (isd) and siderophore-mediated (asb) iron transport pathways in this pathogen. Whereas deletion of theasbgenes results in reduced virulence, the loss of three surface components fromisdhad no effect, thereby leaving open the question of what additional factors inB. anthracisare responsible for iron uptake from the most abundant iron source for mammals, heme. Here, we describe the first functional characterization ofbas0520, a gene recently implicated in anthrax disease progression.bas0520encodes a single near-iron transporter (NEAT) domain and several leucine-rich repeats. The NEAT domain binds heme, despite lacking a stabilizing tyrosine common to the NEAT superfamily of hemoproteins. The NEAT domain also binds hemoglobin and can acquire heme from hemoglobin in solution. Finally, deletion ofbas0520resulted in bacilli unable to grow efficiently on heme or hemoglobin as an iron source and yielded the most significant phenotype relative to that for other putative heme uptake systems, a result that suggests that this protein plays a prominent role in the replication ofB. anthracisin hematogenous environments. Thus, we have assigned the name of Hal (heme-acquisitionleucine-rich repeat protein) to BAS0520. These studies advance our understanding of heme acquisition by this dangerous pathogen and justify efforts to determine the mechanistic function of this novel protein for vaccine or inhibitor development.
Phosphoketolase Pathway for Xylose Catabolism in Clostridium acetobutylicum Revealed by
13
C Metabolic Flux Analysis
Authors: Liu Lixia , Zhang Lei , Tang Wei , Gu Yang , Hua Qiang , Yang Sheng , Jiang Weihong , Yang Chen
Published: August 2012

Solvent-producing clostridia are capable of utilizing pentose sugars, including xylose and arabinose; however, little is known about how pentose sugars are catabolized through the metabolic pathways in clostridia. In this study, we identified the xylose catabolic pathways and quantified their fluxes in
Clostridium acetobutylicum
based on [1-
13
C]xylose labeling experiments. The phosphoketolase pathway was found to be active, which contributed up to 40% of the xylose catabolic flux in
C. acetobutylicum
. The split ratio of the phosphoketolase pathway to the pentose phosphate pathway was markedly increased when the xylose concentration in the culture medium was increased from 10 to 20 g liter
−1
. To our knowledge, this is the first time that the
in vivo
activity of the phosphoketolase pathway in clostridia has been revealed. A phosphoketolase from
C. acetobutylicum
was purified and characterized, and its activity with xylulose-5-P was verified. The phosphoketolase was overexpressed in
C. acetobutylicum
, which resulted in slightly increased xylose consumption rates during the exponential growth phase and a high level of acetate accumulation.
Genome-Wide Responses of the Model Archaeon Halobacterium sp. Strain NRC-1 to Oxygen Limitation
Authors: DasSarma Priya , Zamora Regie C. , Müller Jochen A. , DasSarma Shiladitya
Published: August 2012

As part of a comprehensive postgenomic investigation of the model archaeon
Halobacterium
sp. strain NRC-1, we used whole-genome DNA microarrays to compare transcriptional profiles of cells grown under anaerobic or aerobic conditions. When anaerobic growth supported by arginine fermentation was compared to aerobic growth, genes for arginine fermentation (
arc
) and anaerobic respiration (
dms
), using trimethylamine
N
-oxide (TMAO) as the terminal electron acceptor, were highly upregulated, as was the
bop
gene, required for phototrophic growth. When arginine fermentation was compared to anaerobic respiration with TMAO, the
arc
and
dms
genes were both induced with arginine, while TMAO induced the
bop
gene and major gas vesicle protein (
gvpAC
) genes specifying buoyant gas vesicles. Anaerobic conditions with either TMAO or arginine also upregulated the
cba
genes, encoding one of three cytochrome oxidases. In-frame deletion of two COG3413 family regulatory genes,
bat
and
dmsR
, showed downregulation of the
bop
gene cluster and loss of purple membrane synthesis and downregulation of the
dms
operon and loss of anaerobic respiration capability, respectively. Bioinformatic analysis identified additional regulatory and sensor genes that are likely involved in the full range of cellular responses to oxygen limitation. Our results show that the
Halobacterium
sp. has evolved a carefully orchestrated set of responses to oxygen limitation. As conditions become more reducing, cells progressively increase buoyancy, as well as capabilities for phototrophy, scavenging of molecular oxygen, anaerobic respiration, and fermentation.
Role of the Helicobacter pylori Sensor Kinase ArsS in Protein Trafficking and Acid Acclimation
Authors: Marcus Elizabeth A. , Sachs George , Wen Yi , Feng Jing , Scott David R.
Published: August 2012

Helicobacter pylori
survives and grows at low pHs via acid acclimation mechanisms that enable periplasmic pH homeostasis. Important components include a cytoplasmic urease; a pH-gated urea channel, UreI; and periplasmic α-carbonic anhydrase. To allow the rapid adjustment of periplasmic pH, acid acclimation components are recruited to the inner membrane in acid. The ArsRS two-component system, in an acid-responsive manner, controls the transcription of the urease gene cluster and α-carbonic anhydrase. The aim of this study is to determine the role of ArsS in protein trafficking as a component of acid acclimation.
H. pylori
wild-type and Δ
arsS
bacteria were incubated at acidic and neutral pHs. Intact bacteria, purified membranes, and total protein were analyzed by Western blotting and urease activity measurements. The total urease activity level was decreased in the Δ
arsS
strain, but the acid activation of UreI was unaffected. A 30-min acid exposure increased the level and activity of urease proteins at the membrane in the wild type but not in the Δ
arsS
strain. The urease levels and activity of the Δ
arsS
strain after a 90-min acid exposure were similar to those of the wild type. ArsS, in addition to its role in urease gene transcription, is also involved in the recruitment of urease proteins to the inner membrane to augment acid acclimation during acute acid exposure. Urease membrane recruitment following prolonged acid exposure in the absence of ArsS was similar to that of the wild type, suggesting a compensatory mechanism, possibly regulated by FlgS, underscoring the importance of urease membrane recruitment and activation in periplasmic pH homeostasis.
Nearly Constant Shedding of Diverse Enteric Viruses by Two Healthy Infants
Authors: Kapusinszky Beatrix , Minor Philip , Delwart Eric
Published: August 2012

Stool samples from two healthy infant siblings collected at about weekly intervals during their first year of life were analyzed by PCR for 15 different enteric viral genera.
Adenovirus
,
Aichi virus
,
Anellovirus
,
Astrovirus
,
Bocavirus
,
Enterovirus
,
Parechovirus
,
Picobirnavirus
, and
Rotavirus
were detected. Not detected were
Coronavirus
,
Cardiovirus
,
Cosavirus
,
Salivirus
,
Sapovirus
, and
Norovirus
. Long-term virus shedding, lasting from one to 12 months, was observed for adenoviruses, anelloviruses, bocaviruses, enteroviruses, parechoviruses, and picobirnaviruses. Repeated administration of oral poliovirus vaccine resulted in progressively shorter periods of poliovirus detection. Four nonpolio enterovirus genotypes were also detected. An average of 1.8 distinct human viruses were found per time point. Ninety-two percent (66/72) of the fecal samples tested contained one to five different human viruses. Two British siblings in the mid-1980s showed nearly constant fecal viral shedding. Our results demonstrate that frequent enteric infections with diverse viruses occur during early childhood in the absence of severe clinical symptoms.
Herpes Simplex Virus 1 Ubiquitin Ligase ICP0 Interacts with PML Isoform I and Induces Its SUMO-Independent Degradation
Authors: Cuchet-Lourenço Delphine , Vanni Emilia , Glass Mandy , Orr Anne , Everett Roger D.
Published: August 2012

Herpes simplex virus 1 (HSV-1) immediate-early protein ICP0 localizes to cellular structures known as promyelocytic leukemia protein (PML) nuclear bodies or ND10 and disrupts their integrity by inducing the degradation of PML. There are six PML isoforms with different C-terminal regions in ND10, of which PML isoform I (PML.I) is the most abundant. Depletion of all PML isoforms increases the plaque formation efficiency of ICP0-null mutant HSV-1, and reconstitution of expression of PML.I and PML.II partially reverses this improved replication. ICP0 also induces widespread degradation of SUMO-conjugated proteins during HSV-1 infection, and this activity is linked to its ability to counteract cellular intrinsic antiviral resistance. All PML isoforms are highly SUMO modified, and all such modified forms are sensitive to ICP0-mediated degradation. However, in contrast to the situation with the other isoforms, ICP0 also targets PML.I that is not modified by SUMO, and PML in general is degraded more rapidly than the bulk of other SUMO-modified proteins. We report here that ICP0 interacts with PML.I in both yeast two-hybrid and coimmunoprecipitation assays. This interaction is dependent on PML.I isoform-specific sequences and the N-terminal half of ICP0 and is required for SUMO-modification-independent degradation of PML.I by ICP0. Degradation of the other PML isoforms by ICP0 was less efficient in cells specifically depleted of PML.I. Therefore, ICP0 has two distinct mechanisms of targeting PML: one dependent on SUMO modification and the other via SUMO-independent interaction with PML.I. We conclude that the ICP0-PML.I interaction reflects a countermeasure to PML-related antiviral restriction.
Complete Genome Sequences of Novel Canine Noroviruses in Hong Kong
Authors: Tse Herman , Lau Susanna K. P. , Chan Wan-Mui , Choi Garnet K. Y. , Woo Patrick C. Y. , Yuen Kwok-Yung
Published: August 2012

We report the complete genome sequences of two novel isolates of norovirus isolated from the fecal swab specimens of dogs in Hong Kong. The complete viral genome is approximately 7.6 kb in length and consists of 3 overlapping open reading frames encoding the ORF1 polyprotein, VP1, and VP2, respectively. Analysis of the VP1 sequence suggested that these noroviruses are divergent from known noroviruses and may represent a novel phylogenetic clade within the genus.
Genome Sequence of Herpes Simplex Virus 1 Strain McKrae
Authors: Macdonald Stuart J. , Mostafa Heba H. , Morrison Lynda A. , Davido David J.
Published: August 2012

The herpes simplex virus 1 (HSV-1) strain McKrae is highly virulent compared to other wild-type strains of HSV-1. To help us better understand the genetic determinants that lead to differences in the pathogenicity of McKrae and other HSV-1 strains, we sequenced its genome. Comparing the sequence of McKrae's genome to that of strain 17 revealed that the genomes differ by at least 752 single nucleotide polymorphisms (SNPs) and 86 insertion/deletion events (indels). Although the majority of these polymorphisms reside in noncoding regions, 241 SNPs and 10 indels alter the protein-coding sequences of 58 open reading frames. Some of these variations are expected to contribute to the pathogenic phenotype of McKrae.
Complete Genome Sequencing of a Novel Newcastle Disease Virus Isolate Circulating in Layer Chickens in the Dominican Republic
Authors: Courtney Sean C. , Gomez Dejelia , Susta Leonardo , Hines Nichole , Pedersen Janice C. , Miller Patti J. , Afonso Claudio L.
Published: August 2012

Newcastle disease virus (NDV) was isolated from an outbreak in layer chickens in the Dominican Republic in 2008. Infections with this isolate led to a 100% apparent case fatality rate in birds. Complete genome sequencing revealed that the isolate does not belong to any of the previously described NDV genotypes. Similarly, large differences were observed in the amino acid sequence of the fusion and hemagglutinin-neuraminidase proteins in comparison with all known NDV genotypes, suggesting the existence of an unknown reservoir for NDV. The work presented here represents the first complete genome sequence of NDV in the Dominican Republic.
Vaccinia Virus Virion Membrane Biogenesis Protein A11 Associates with Viral Membranes in a Manner That Requires the Expression of Another Membrane Biogenesis Protein, A6
Authors: Wu Xiang , Meng Xiangzhi , Yan Bo , Rose Lloyd , Deng Junpeng , Xiang Yan
Published: August 2012

A group of vaccinia virus (VACV) proteins, including A11, L2, and A6, are required for biogenesis of the primary envelope of VACV, specifically, for the acquisition of viral membrane precursors. However, the interconnection among these proteins is unknown and, with the exception of L2, the connection of these proteins with membranes is also unknown. In this study, prompted by the findings that A6 coprecipitated A11 and that the cellular distribution of A11 was dramatically altered by repression of A6 expression, we studied the localization of A11 in cells by using immunofluorescence and cell fractionation analysis. A11 was found to associate with membranes and colocalize with virion membrane proteins in viral replication factories during normal VACV replication. A11 partitioned almost equally between the detergent and aqueous phases upon Triton X-114 phase separation, demonstrating an intrinsic affinity with lipids. However, in the absence of infection or VACV late protein synthesis, A11 did not associate with cellular membranes. Furthermore, when A6 expression was repressed, A11 did not colocalize with any viral membrane proteins or associate with membranes. In contrast, when virion envelope formation was blocked at a later step by repression of A14 expression or by rifampin treatment, A11 colocalized with virion membrane proteins in the factories. Altogether, our data showed that A11 associates with viral membranes during VACV replication, and this association requires A6 expression. This study provides a physical connection between A11 and viral membranes and suggests that A6 regulates A11 membrane association.
HIV-1 Neutralizing Antibodies Display Dual Recognition of the Primary and Coreceptor Binding Sites and Preferential Binding to Fully Cleaved Envelope Glycoproteins
Authors: Li Yuxing , O'Dell Sijy , Wilson Richard , Wu Xueling , Schmidt Stephen D. , Hogerkorp Carl-Magnus , Louder Mark K. , Longo Nancy S. , Poulsen Christian , Guenaga Javier , Chakrabarti Bimal K. , Doria-Rose Nicole , Roederer Mario , Connors Mark , Mascola John R. , Wyatt Richard T.
Published: August 2012

The gp120 CD4 binding site (CD4bs) and coreceptor binding site (CoRbs) are two functionally conserved elements of the HIV-1 envelope glycoproteins (Env). We previously defined the presence of CD4bs-neutralizing antibodies in the serum of an HIV-1-infected individual and subsequently isolated the CD4bs-specific monoclonal antibodies (MAbs) VRC01 and VRC03 from the memory B cell population. Since this donor's serum also appeared to contain neutralizing antibodies to the CoRbs, we employed a differential fluorescence-activated cell sorter (FACS)-based sorting strategy using an Env trimer possessing a CoRbs knockout mutation (I420R) to isolate specific B cells. The MAb VRC06 was recovered from these cells, and its genetic sequence allowed us to identify a clonal relative termed VRC06b, which was isolated from a prior cell sort using a resurfaced core gp120 probe and its cognate CD4bs knockout mutant. VRC06 and VRC06b neutralized 22% and 44% of viruses tested, respectively. Epitope mapping studies revealed that the two MAbs were sensitive to mutations in both the gp120 CoRbs and the CD4bs and could cross-block binding of both CD4bs and CoRbs MAbs to gp120. Fine mapping indicated contacts within the gp120 bridging sheet and the base of the third major variable region (V3), which are elements of the CoRbs. Cell surface binding assays demonstrated preferential recognition of fully cleaved Env trimers over uncleaved trimers. Thus, VRC06 and VRC06b are Env trimer precursor cleavage-sensitive neutralizing MAbs that bind to a region of gp120 that overlaps both the primary and the secondary HIV-1 receptor binding sites.
Structure, Function, and Evolution of the Crimean-Congo Hemorrhagic Fever Virus Nucleocapsid Protein
Authors: Carter Stephen D. , Surtees Rebecca , Walter Cheryl T. , Ariza Antonio , Bergeron Éric , Nichol Stuart T. , Hiscox Julian A. , Edwards Thomas A. , Barr John N.
Published: August 2012

Crimean-Congo hemorrhagic fever virus (CCHFV) is an emerging tick-borne virus of the
Bunyaviridae
family that is responsible for a fatal human disease for which preventative or therapeutic measures do not exist. We solved the crystal structure of the CCHFV strain Baghdad-12 nucleocapsid protein (N), a potential therapeutic target, at a resolution of 2.1 Å. N comprises a large globular domain composed of both N- and C-terminal sequences, likely involved in RNA binding, and a protruding arm domain with a conserved DEVD caspase-3 cleavage site at its apex. Alignment of our structure with that of the recently reported N protein from strain YL04057 shows a close correspondence of all folds but significant transposition of the arm through a rotation of 180 degrees and a translation of 40 Å. These observations suggest a structural flexibility that may provide the basis for switching between alternative N protein conformations during important functions such as RNA binding and oligomerization. Our structure reveals surfaces likely involved in RNA binding and oligomerization, and functionally critical residues within these domains were identified using a minigenome system able to recapitulate CCHFV-specific RNA synthesis in cells. Caspase-3 cleaves the polypeptide chain at the exposed DEVD motif; however, the cleaved N protein remains an intact unit, likely due to the intimate association of N- and C-terminal fragments in the globular domain. Structural alignment with existing N proteins reveals that the closest CCHFV relative is not another bunyavirus but the arenavirus Lassa virus instead, suggesting that current segmented negative-strand RNA virus taxonomy may need revision.
Filamentous Influenza Virus Enters Cells via Macropinocytosis
Authors: Rossman Jeremy S. , Leser George P. , Lamb Robert A.
Published: August 2012

Influenza virus is pleiomorphic, producing both spherical (100-nm-diameter) and filamentous (100-nm by 20-μm) virions. While the spherical virions are known to enter host cells through exploitation of clathrin-mediated endocytosis, the entry pathway for filamentous virions has not been determined, though the existence of an alternative, non-clathrin-, non-caveolin-mediated entry pathway for influenza virus has been known for many years. In this study, we confirm recent results showing that influenza virus utilizes macropinocytosis as an alternate entry pathway. Furthermore, we find that filamentous influenza viruses use macropinocytosis as the primary entry mechanism. Virions enter cells as intact filaments within macropinosomes and are trafficked to the acidic late-endosomal compartment. Low pH triggers a conformational change in the M2 ion channel protein, altering membrane curvature and leading to a fragmentation of the filamentous virions. This fragmentation may enable more-efficient fusion between the viral and endosomal membranes.
A rare presentation of cleidocranial dysplasia
Authors: Broeks Ilse , Veenstra-Knol Irma E , Kamps Arvid W A
Published: August 2012

Cleidocranial dysplasia (CCD) is a rare skeletal dysplasia characterised by a defect in ossification. Frequently reported clinical findings are delayed closure of the fontanelles and cranial sutures, hypoplastic clavicles, dental abnormalities and short stature. Our patient suffered from complete absence of ossification of both parietal bones. This is a rare and severe defect that has been reported in only a few patients with CCD.
Presentation of opsoclonus myoclonus ataxia syndrome with glutamic acid decarboxylase antibodies
Authors: Bhandari Hanul Srinivas
Published: August 2012

In this rare case, the patient presented with opsoclonus, myoclonus and ataxia. Serological and imaging studies revealed high glutamic acid decarboxylase antibody (GAD-Ab) levels. High-dose corticosteroids were of no benefit and subsequent intravenous immunoglobulin (IVIg) administration proved resolution of the condition. Levetiracetam proved useful in symptomatically controlling the myoclonus. Follow-up GAD-Ab levels were within normal limits.
Rectus femoris muscle injuries in football: a clinically relevant review of mechanisms of injury, risk factors and preventive strategies
Authors: Mendiguchia Jurdan , Alentorn-Geli Eduard , Idoate Fernando , Myer Gregory D
Published: August 2012

Quadriceps muscle strains frequently occur in sports that require repetitive kicking and sprinting, and are common in football in its different forms around the world. This paper is a review of aetiology, mechanism of injury and the natural history of rectus femoris injury. Investigating the mechanism and risk factors for rectus femoris muscle injury aims to allow the development of a framework for future initiatives to prevent quadriceps injury in football players.
Clinical implications and validity of nursing assessments: a longitudinal measure of patient condition from analysis of the Electronic Medical Record
Authors: Rothman Michael J , Solinger Alan B , Rothman Steven I , Finlay G Duncan
Published: August 2012

Objectives

This study investigates risk of mortality associated with nurses’ assessments of patients by physiological system. We hypothesise that nursing assessments of in-patients performed at entry correlate with in-hospital mortality, and those performed just before discharge correlate with postdischarge mortality.

Design

Cohort study of in-hospital and postdischarge mortality of patients over two 1-year periods.

Setting

An 805-bed community hospital in Sarasota, Florida, USA.

Subjects

42 302 inpatients admitted for any reason, excluding obstetrics, paediatric and psychiatric patients.

Outcome measures

All-cause mortalities and mortality OR.

Results

Patients whose entry nursing assessments, other than pain, did not meet minimum standards had significantly higher in-hospital mortality than patients meeting minimums; and final nursing assessments before discharge had large OR for postdischarge mortality. In-hospital mortality OR were found to be: food, 7.0; neurological, 9.4; musculoskeletal, 6.9; safety, 5.6; psychosocial, 6.7; respiratory, 8.1; skin, 5.2; genitourinary, 3.0; gastrointestinal, 2.3; peripheral-vascular, 3.9; cardiac, 2.8; and pain, 1.1. CI at 95% are within ±20% of these values, with p<0.001 (except for pain). Similar results applied to postdischarge mortality. All results were comparable across the two 1-year periods, with 0.85 intraclass correlation coefficient.

Conclusions

Nursing assessments are strongly correlated with in-hospital and postdischarge mortality. No multivariate analysis has yet been performed, and will be the subject of a future study, thus there may be confounding factors. Nonetheless, we conclude that these assessments are clinically meaningful and valid. Nursing assessment data, which are currently unused, may allow physicians to improve patient care. The mortality OR and the dynamic nature of nursing assessments suggest that nursing assessments are sensitive indicators of a patient's condition. While these conclusions must remain qualified, pending future multivariate analyses, nursing assessment data ought to be incorporated in risk-related health research, and changes in record-keeping software are needed to make this information more accessible.
Impact of one or two visits strategy on hypertension burden estimation in HYDY, a population-based cross-sectional study: implications for healthcare resource allocation decision making
Authors: Modesti Pietro Amedeo , Rapi Stefano , Bamoshmoosh Mohamed , Baldereschi Marzia , Massetti Luciano , Padeletti Luigi , Gensini Gian Franco , Zhao Dong , Al-Hidabi Dawood , Al Goshae Husni
Published: August 2012

Context

The prevalence of hypertension in developing countries is coming closer to values found in developed countries. However, surveys usually rely on readings taken at a single visit, the option to implement the diagnosis on readings taken at multiple visits, being limited by costs.

Objective

To estimate more accurately the magnitude and extent of the resource that should be allocated to the prevention of hypertension.

Design

Population-based cross-sectional survey with triplicate blood pressure (BP) readings taken on two separate home-visits.

Setting

Rural and urban locations in three areas of Yemen (capital, inland and coast).

Participants

A nationally representative sample of the Yemen population aged 15–69 years (5063 men and 5179 women), with an overall response rate of 92% in urban and 94% in rural locations.

Main outcome measure

Hypertension diagnosed as systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg and/or self-reported use of antihypertensive drugs.

Results

Hypertension prevalence (age-standardised to the WHO world population 2001) based on fulfilling the same criteria on both visits (11.3%; 95% Cl 10.7% to 11.9%), was 35% lower than estimation based on the first visit (17.3%; 16.5% to 18.0%). Advanced age, blood glucose ≥7 mmol/l or proteinuria ≥1+ at dipstick test at visit one were significant predictors of confirmation at visit 2. The 959 participants found to be hypertensive at visit 1 or at visit 2 only and thus excluded from the final diagnosis had a rate of proteinuria (5.0%; 3.8% to 6.5%) comparable to rates of the general population (6.1%; 5.6% to 6.6%), and of subjects normotensive at both visits (5.6%; 5.1% to 6.2%). Only 1.9% of Yemen population classified at high or very high cardiovascular (CV) risk at visit 1 moved to average, low or moderate CV risk categories after two visits.

Conclusions

Hypertension prevalence based on readings obtained after two visits is 35% lower than estimation based on the first visit, subjects were excluded from final diagnosis belonging to low CV risk classes.
Using care profiles as a catalyst for improving end of life commissioning, involvement and service delivery
Authors: Gandy Robert , Roe Brenda
Published: August 2012

Objectives

In 2010, Liverpool Primary Care Trust successfully pioneered a care profiles approach to commissioning End of Life (EoL) services. They established service requirements for each stage of the EoL pathway, and set out skill mix, delivery, quality and outcomes. This feature sets out how the approach can also support local work relating to Advance Care Planning, palliative care funding tariffs and patient and public involvement.

Situation

Local EoL services vary, reflecting geography, history, service models and resources. Few commissioners know in detail how all EoL services and resources systematically inter-relate, particularly those involving non-specialist services. Also, anecdotal evidence indicates that information provided by healthcare professionals to patients and carers is not necessarily consistent or complete.

Finances

The planned introduction of per patient tariffs for palliative care in 2015 means commissioners must be clear about what EoL services are and what are not covered by the tariffs, and how this might impact on service delivery and contracts.

Information

A multi-disciplinary workshop established that by clarifying what services are commissioned locally, EoL care profiles can provide detailed information to ensure patients and carers receive comprehensive, consistent, quality information to support their Advanced Care Planning. They can address gaps in EoL information prescriptions and enable transparent information for patient and public involvement.

Conclusions

EoL care profiles enable local services to be commissioned in detail, which is a catalyst and essential precursor for an inclusive and explicit approach to planning and resourcing services for individual patients and the population as a whole.
Is informal caregiving independently associated with poor health? A population-based study
Authors: Legg Lynn , Weir Chris J , Langhorne P , Smith L N , Stott D J
Published: August 2012

Background

Providing informal care has been linked with poor health but has not previously been studied across a whole population. We aimed to study the association between informal care provision and self-reported poor health.

Method

We used data from the UK 2001 Census. The relationship between informal caregiving and poor health was modelled using logistic regression, adjusting for age, sex, marital status, ethnicity, economic activity and educational attainment.

Results

We included 44 465 833 individuals free from permanent sickness or disability. 5 451 902 (12.3%) participants reported providing informal care to another person. There was an association between provision of informal caregiving and self-reported poor health; OR 1.100, 95% CI 1.096 to 1.103. This association remained after adjustment for age, sex, ethnic group, marital status, economic activity and educational attainment. The association also increased with the amount of care provided (hours per week).

Conclusions

Around one in eight of the UK population reports that he or she is an informal caregiver. This activity is associated with poor health, particularly in those providing over 20 h care per week.
Unprotected fellatio between female sex workers and their clients in Sydney, Australia
Authors: Read Phillip J , Wand Handan , Guy Rebecca , Donovan Basil , McNulty Anna M
Published: August 2012

Objectives

To assess the frequency and predictors of inconsistent condom use for fellatio at work by female sex workers (FSW) in Sydney and the prevalence of pharyngeal gonorrhoea and other sexually transmitted infections in these women.

Methods

Cross-sectional study including all FSW attending the Sydney Sexual Health Centre for sexually transmitted infection screening between May 2009 and January 2011 and reporting fellatio at work. Univariate and multivariate regression was used to identify predictors of inconsistent condom use for fellatio.

Results

Of 1540 FSW who offered fellatio at work, 372 (25%) reported inconsistent condom use for this fellatio. In multivariate analysis, speaking Mandarin or Cantonese rather than English (adjusted OR (AOR) 2.03, 95% CI 1.44 to 2.86), reporting inconsistent condom use for vaginal sex at work (AOR 10.82, 95% CI 6.13 to 19.09), reporting no vaginal sex at work (AOR 7.48, 95% CI 2.42 to 23.12) and being a new client to the clinic (AOR 2.10, 95% CI 1.56 to 2.83) were associated with inconsistent condom use for fellatio. Thai-speaking women were less likely to report unprotected fellatio (AOR 0.36, 95% CI 0.23 to 0.57). 17 women were diagnosed with pharyngeal gonorrhoea (AOR 1.1%, 95% CI 0.6% to 1.7%).

Conclusions

Condom use for fellatio by Sydney FSW varies by work location and language spoken. Health promotion targeting these at-risk women is warranted. Women working in brothels masquerading as massage parlours were particularly likely to report inconsistent condom use for fellatio. Local government reluctance to approve brothels may be contributing to this problem.
Anaemia in the sow: a cohort study to assess factors with an impact on haemoglobin concentration, and the influence of haemoglobin concentration on the reproductive performance
Authors: Normand V. , Perrin H. , Auvigne V. , Robert N. , Laval A.
Published: August 2012

The aim of this study was to conduct a descriptive study of haemoglobin concentration found on high‐prolificacy sows, to study the relationship between the concentration of haemoglobin and body reserves, and to determine whether anaemia is a risk factor for reproductive performance. A cohort of 308 sows from seven farms was followed from the last third of gestation to the confirmation of the following gestation. Haemoglobin concentration was assessed at four stages of the reproductive cycle: seven and four weeks before farrowing, a few days and three weeks after farrowing. Backfat thickness (BFT) was measured at parturition. The results were analysed using linear mixed‐effect models. The mean haemoglobin concentration was 108.4 g/l. The mean modellised haemoglobin concentration of parity 1 sows with a BFT of 16 mm, sampled seven weeks before farrowing, was 118 g/l. Haemoglobin concentration of sows of parity 6 or higher was 8.0 g/l lower than those of parity 1 sows (95% confidence interval −11.0 to −5.1). Haemoglobin concentration is lower in sows with a lower BFT, whatever parity rank. There is no evidence of a relation between haemoglobin concentration and the number of total born, stillborn or number of piglets alive at three weeks and the next breeding performance.
Synthesis of heteroleptic pyrrolide/bipyridyl complexes of ruthenium(II)
Authors: Lundrigan Travis , Jackson Carla L.M. , Uddin Md. Imam , Tucker Lloyd A. , Ali Adeeb Al-Sheikh , Linden Anthony , Cameron T. Stanley , Thompson Alison
Published: August 2012

The synthesis and characterization of the first heteroleptic pyrrolide/2,2′-bipyridyl complexes of ruthenium(II) are reported. Pyrroles substituted at the 2-position with X = O functionality react with Ru(bipy)2Cl2·2H2O to form complexes in which the pyrrolide ligands chelate to Ru(II). The library of pyrroles includes 2-formyl, 2-keto, 2-carboxylato, 2-sulfinyl, and 2-sulfonyl derivatives.
Identification of new checkpoint kinase-1 (Chk1) inhibitors by docking, 3D-QSAR, and pharmacophore-modeling methods
Authors: Ambre Premlata K. , Pissurlenkar Raghuvir R. S. , Coutinho Evans C. , Iyer Radhakrishnan P.
Published: August 2012

Inhibition of checkpoint kinase-1 (Chk1) by small molecules is of great therapeutic interest in the field of oncology and for understanding cell-cycle regulations. This paper presents a model with elements from docking, pharmacophore mapping, the 3D-QSAR approaches CoMFA, CoMSIA and CoRIA, and virtual screening to identify novel hits against Chk1. Docking, 3D-QSAR (CoRIA, CoMFA and CoMSIA), and pharmacophore studies delineate crucial site points on the Chk1 inhibitors, which can be modified to improve activity. The docking analysis showed residues in the proximity of the ligands that are involved in ligand–receptor interactions, whereas CoRIA models were able to derive the magnitude of these interactions that impact the activity. The ligand-based 3D-QSAR methods (CoMFA and CoMSIA) highlight key areas on the molecules that are beneficial and (or) detrimental for activity. The docking studies and 3D-QSAR models are in excellent agreement in terms of binding-site interactions. The pharmacophore hypotheses validated using sensitivity, selectivity, and specificity parameters is a four-point model, characterized by a hydrogen-bond acceptor (A), hydrogen-bond donor (D), and two hydrophobes (H). This map was used to screen a database of 2.7 million druglike compounds, which were pruned to a small set of potential inhibitors by CoRIA, CoMFA, and CoMSIA models with predicted activity in the range of 8.5–10.5 log units.
THE ROLE OF DARK MATTER INTERACTION IN GALAXY CLUSTERS
Authors: PELLICER C. E. , FERREIRA ELISA G. M. , GUARIENTO DANIEL C. , COSTA ANDRÉ A. , GRAEF LEILA L. , COELHO ANDREA , ABDALLA ELCIO
Published: August 2012

We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to ΛCDM predictions. The interaction parameters are found via a genetic algorithm search. The results obtained suggest that interaction is a basic phenomenon whose effects are detectable even in simple models of galactic dynamics.