bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acylhydrazones as Antifungal Agents Targeting the Synthesis of Fungal Sphingolipids
Authors: Lazzarini Cristina , Haranahalli Krupanandan , Rieger Robert , Ananthula Hari Krishna , Desai Pankaj B. , Ashbaugh Alan , Linke Michael J. , Cushion Melanie T. , Ruzsicska Bela , Haley John , Ojima Iwao , Del Poeta Maurizio 
Published: March 2018

ABSTRACT

The incidence of invasive fungal infections has risen dramatically in recent decades. Current antifungal drugs are either toxic, likely to interact with other drugs, have a narrow spectrum of activity, or induce fungal resistance. Hence, there is a great need for new antifungals, possibly with novel mechanisms of action. Previously our group reported an acylhydrazone called BHBM that targeted the sphingolipid pathway and showed strong antifungal activity against several fungi. In this study, we screened 19 derivatives of BHBM. Three out of 19 derivatives were highly active against
Cryptococcus neoformans
in vitro
and had low toxicity in mammalian cells. In particular, one of them, called D13, had a high selectivity index and showed better activity in an animal model of cryptococcosis, candidiasis, and pulmonary aspergillosis. D13 also displayed suitable pharmacokinetic properties and was able to pass through the blood-brain barrier. These results suggest that acylhydrazones are promising molecules for the research and development of new antifungal agents.
P174E Substitution in GES-1 and GES-5 β-Lactamases Improves Catalytic Efficiency toward Carbapenems
Authors: Piccirilli Alessandra , Mercuri Paola Sandra , Galleni Moreno , Aschi Massimiliano , Matagne André , Amicosante Gianfranco , Perilli Mariagrazia 
Published: March 2018

ABSTRACT

GES-type β-lactamases are a group of enzymes that have evolved their hydrolytic activity against carbapenems. In this study, the role of residue 174 inside the Ω-loop of GES-1 and GES-5 was investigated. GES-1
P174E
and GES-5
P174E
mutants, selected by site saturation mutagenesis, were purified and kinetically characterized. In comparison with GES-1 and GES-5 wild-type enzymes, GES-1
P174E
and GES-5
P174E
mutants exhibited lower
k
cat
and
k
cat
/

K
m

values for cephalosporins and penicillins. Concerning carbapenems, GES-1
P174E
shared higher
k
cat
values but lower

K
m

values than those calculated for GES-1. The GES-1
P174E
and GES-5
P174E
mutants showed high hydrolytic efficiency for imipenem, with
k
cat
/

K
m

values 100- and 660-fold higher, respectively, than those of GES-1. Clavulanic acid and tazobactam are good inhibitors for both GES-1
P174E
and GES-5
P174E
. Molecular dynamic (MD) simulations carried out for GES-1, GES-5, GES-1
P174E
, and GES-5
P174E
complexed with imipenem and meropenem have shown that mutation at position 174 induces a drastic increase of enzyme flexibility, in particular in the Ω-loop. The circular dichroism (CD) spectroscopy spectra of the four enzymes indicate that the P174E substitution in GES-1 and GES-5 does not affect the secondary structural content of the enzymes.
Two
rsaM
Homologues Encode Central Regulatory Elements Modulating Quorum Sensing in Burkholderia thailandensis
Authors: Le Guillouzer Servane , Groleau Marie-Christine , Déziel Eric 
Published: March 2018

ABSTRACT

The bacterium
Burkholderia thailandensis
possesses three
N
-acyl-
l
-homoserine lactone (AHL) quorum sensing (QS) systems designated BtaI1/BtaR1 (QS-1), BtaI2/BtaR2 (QS-2), and BtaI3/BtaR3 (QS-3). These QS systems are associated with the biosynthesis of
N
-octanoyl-homoserine lactone (C
8
-HSL),
N
-3-hydroxy-decanoyl-homoserine lactone (3OHC
10
-HSL), and
N
-3-hydroxy-octanoyl-homoserine lactone (3OHC
8
-HSL), which are produced by the LuxI-type synthases BtaI1, BtaI2, and BtaI3 and modulated by the LuxR-type transcriptional regulators BtaR1, BtaR2, and BtaR3. The
btaR1-btaI1
and
btaR2-btaI2
gene clusters each carry an additional gene encoding a homologue of the QS repressor RsaM originally identified in the phytopathogen
Pseudomonas fuscovaginae
and thus here named
rsaM1
and
rsaM2
, respectively. We have characterized the functions of these two conserved
rsaM
homologues and demonstrated their involvement in the regulation of AHL biosynthesis in
B. thailandensis
strain E264. We quantified the production of C
8
-HSL, 3OHC
10
-HSL, and 3OHC
8
-HSL by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the wild-type strain and in the
rsaM1
and
rsaM2
mutants, and we monitored
btaI1
,
btaI2
, and
btaI3
expression using chromosomal mini-CTX-
lux
transcriptional reporters. The transcription of
btaR1
,
btaR2
, and
btaR3
was also measured by quantitative reverse transcription-PCR (qRT-PCR). We observed that RsaM1 mainly represses the QS-1 system, whereas RsaM2 principally represses the QS-2 system. We also found that both
rsaM1
and
rsaM2
are QS controlled and negatively autoregulated. We conclude that RsaM1 and RsaM2 are an integral part of the QS circuitry of
B. thailandensis
and play a major role in the hierarchical and homeostatic organization of the QS-1, QS-2, and QS-3 systems.

IMPORTANCE
Quorum sensing (QS) is commonly involved in the coordination of gene transcription associated with the establishment of host-pathogen interactions and acclimatization to the environment. We present the functional characterization of two
rsaM
homologues in the regulation of the multiple QS systems coexisting in the nonpathogenic bacterium
Burkholderia thailandensis
, which is widely used as a model system for the study of the human pathogen
Burkholderia pseudomallei
. We found that inactivation of these
rsaM
homologues, which are clustered with the other QS genes, profoundly affects the QS circuitry of
B. thailandensis
. We conclude that they constitute essential regulatory components of the QS modulatory network and provide additional layers of regulation to modulate the transcription of QS-controlled genes, particularly those linked to environmental adaptation.
A Bacterial Microcompartment Is Used for Choline Fermentation by Escherichia coli 536
Authors: Herring Taylor I. , Harris Tiffany N. , Chowdhury Chiranjit , Mohanty Sujit Kumar , Bobik Thomas A. 
Published: March 2018

ABSTRACTBacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization byProteusandDesulfovibriospecies. However, many aspects of this process have not been fully defined. Here, we investigate choline degradation by the uropathogenEscherichia coli536. Growth studies indicatedE. coli536 degrades choline primarily by fermentation. Electron microscopy indicated that a bacterial microcompartment was used for this process. Bioinformatic analyses suggested that the choline utilization (cut) gene cluster ofE. coli536 includes two operons, one containing three genes and a main operon of 13 genes. Regulatory studies indicate that thecutXgene encodes a positive transcriptional regulator required for induction of the maincutoperon in response to choline supplementation. Each of the 16 genes in thecutcluster was individually deleted, and phenotypes were examined. ThecutX,cutY,cutF,cutO,cutC,cutD,cutU, andcutVgenes were required for choline degradation, but the remaining genes of thecutcluster were not essential under the conditions used. The reasons for these varied phenotypes are discussed.IMPORTANCEHere, we investigate choline degradation inE. coli536. These studies provide a basis for understanding a new type of bacterial microcompartment and may provide deeper insight into the link between choline degradation in the human gut and cancer and heart disease. These are also the first studies of choline degradation inE. coli536, an organism for which sophisticated genetic analysis methods are available. In addition, thecutgene cluster ofE. coli536 is located in pathogenicity island II (PAI-II536) and hence might contribute to pathogenesis.
Nucleotide Sequence Database Comparison for Routine Dermatophyte Identification by Internal Transcribed Spacer 2 Genetic Region DNA Barcoding
Authors: Normand A. C. , Packeu A. , Cassagne C. , Hendrickx M. , Ranque S. , Piarroux R. 
Published: March 2018

ABSTRACT

Conventional dermatophyte identification is based on morphological features. However, recent studies have proposed to use the nucleotide sequences of the rRNA internal transcribed spacer (ITS) region as an identification barcode of all fungi, including dermatophytes. Several nucleotide databases are available to compare sequences and thus identify isolates; however, these databases often contain mislabeled sequences that impair sequence-based identification. We evaluated five of these databases on a clinical isolate panel. We selected 292 clinical dermatophyte strains that were prospectively subjected to an ITS2 nucleotide sequence analysis. Sequences were analyzed against the databases, and the results were compared to clusters obtained via DNA alignment of sequence segments. The DNA tree served as the identification standard throughout the study. According to the ITS2 sequence identification, the majority of strains (255/292) belonged to the genus
Trichophyton
, mainly
T. rubrum
complex (
n
= 184),
T. interdigitale
(
n
= 40),
T. tonsurans
(
n
= 26), and
T. benhamiae
(
n
= 5). Other genera included
Microsporum
(e.g.,
M. canis
[
n
= 21],
M. audouinii
[
n
= 10],
Nannizzia gypsea
[
n
= 3], and
Epidermophyton
[
n
= 3]). Species-level identification of
T. rubrum
complex isolates was an issue. Overall, ITS DNA sequencing is a reliable tool to identify dermatophyte species given that a comprehensive and correctly labeled database is consulted. Since many inaccurate identification results exist in the DNA databases used for this study, reference databases must be verified frequently and amended in line with the current revisions of fungal taxonomy. Before describing a new species or adding a new DNA reference to the available databases, its position in the phylogenetic tree must be verified.
Validation of a Human Papillomavirus (HPV) DNA Cervical Screening Test That Provides Expanded HPV Typing
Authors: Demarco Maria , Carter-Pokras Olivia , Hyun Noorie , Castle Philip E. , He Xin , Dallal Cher M. , Chen Jie , Gage Julia C. , Befano Brian , Fetterman Barbara , Lorey Thomas , Poitras Nancy , Raine-Bennett Tina R. , Wentzensen Nicolas , Schiffman Mark 
Published: March 2018

ABSTRACT

As cervical cancer screening shifts from cytology to human papillomavirus (HPV) testing, a major question is the clinical value of identifying individual HPV types. We aimed to validate Onclarity (Becton Dickinson Diagnostics, Sparks, MD), a nine-channel HPV test recently approved by the FDA, by assessing (i) the association of Onclarity types/channels with precancer/cancer; (ii) HPV type/channel agreement between the results of Onclarity and cobas (Roche Molecular Systems, Pleasanton, CA), another FDA-approved test; and (iii) Onclarity typing for all types/channels compared to typing results from a research assay (linear array [LA]; Roche). We compared Onclarity to histopathology, cobas, and LA. We tested a stratified random sample (
n
= 9,701) of discarded routine clinical specimens that had tested positive by Hybrid Capture 2 (HC2; Qiagen, Germantown, MD). A subset had already been tested by cobas and LA (
n
= 1,965). Cervical histopathology was ascertained from electronic health records. Hierarchical Onclarity channels showed a significant linear association with histological severity. Onclarity and cobas had excellent agreement on partial typing of HPV16, HPV18, and the other 12 types as a pool (sample-weighted kappa value of 0.83); cobas was slightly more sensitive for HPV18 and slightly less sensitive for the pooled high-risk types. Typing by Onclarity showed excellent agreement with types and groups of types identified by LA (kappa values from 0.80 for HPV39/68/35 to 0.97 for HPV16). Onclarity typing results corresponded well to histopathology and to an already validated HPV DNA test and could provide additional clinical typing if such discrimination is determined to be clinically desirable.
Tunneling Nanotubes as a Novel Route of Cell-to-Cell Spread of Herpesviruses
Authors: Panasiuk Mirosława , Rychłowski Michał , Derewońko Natalia , Bieńkowska-Szewczyk Krystyna 
Published: March 2018

ABSTRACT
Various types of intercellular connections that are essential for communication between cells are often utilized by pathogens. Recently, a new type of cellular connection, consisting of long, thin, actin-rich membrane extensions named tunneling nanotubes (TNTs), has been shown to play an important role in cell-to-cell spread of HIV and influenza virus. In the present report, we show that TNTs are frequently formed by cells infected by an alphaherpesvirus, bovine herpesvirus 1 (BoHV-1). Viral proteins, such as envelope glycoprotein E (gE), capsid protein VP26, and tegument protein Us3, as well as cellular organelles (mitochondria) were detected by immunofluorescence and live-cell imaging of nanotubes formed by bovine primary fibroblasts and oropharynx cells (KOP cells). Time-lapse confocal studies of live cells infected with fluorescently labeled viruses showed that viral particles were transmitted via TNTs. This transfer also occurred in the presence of neutralizing antibodies, which prevented free entry of BoHV-1. We conclude that TNT formation contributes to successful cell-to-cell spread of BoHV-1 and demonstrate for the first time the participation of membrane nanotubes in intercellular transfer of a herpesvirus in live cells.

IMPORTANCE
Efficient transmission of viral particles between cells is an important factor in successful infection by herpesviruses. Herpesviruses can spread by the free-entry mode or direct cell-to-cell transfer via cell junctions and long extensions of neuronal cells. In this report, we show for the first time that an alphaherpesvirus can also spread between various types of cells using tunneling nanotubes, intercellular connections that are utilized by HIV and other viruses. Live-cell monitoring revealed that viral transmission occurs between the cells of the same type as well as between epithelial cells and fibroblasts. This newly discovered route of herpesviruses spread may contribute to efficient transmission despite the presence of host immune responses, especially after reactivation from latency that developed after primary infection. Long-range communication provided by TNTs may facilitate the spread of herpesviruses between many tissues and organs of an infected organism.
Children’s toothache is becoming everybody’s business: where do parents go when their children have oral pain in London, England? A cross-sectional analysis
Authors: Muirhead Vanessa Elaine , Quayyum Zahidul , Markey Donal , Weston-Price Sally , Kimber Annette , Rouse Wayne , Pine Cynthia M 
Published: March 2018

ObjectivesTo assess the number of parents who visited community pharmacies in London seeking pain medications for their children’s pain and specifically for oral pain, to identify which health services parents contacted before their pharmacy visit and to estimate the cost to the National Health Service (NHS) when children with oral pain who visit pharmacies also see health professionals outside dentistry.DesignA cross-sectional study.Setting1862 pharmacies in London in November 2016–January 2017.ParticipantsParents, carers and adolescents purchasing over-the-counter pain medications or collecting pain prescriptions for children (0–19 years).Brief interventionA survey administered by pharmacy staff to participants and a guidance pack.Main outcome measuresThe number of parents who visited pharmacies seeking pain medications for their children’s pain and oral pain and the number of parents who contacted health professionals outside dentistry before their pharmacy visit. Estimated costs of visits by children with oral pain to health professionals outside dentistry.ResultsOne in two (951) pharmacies participated collecting information from 6915 parents seeking pain medications for their children. The majority (65%) of parents sought pain medications to relieve their children’s oral pain. Only 30% of children with oral pain had seen a dentist before the pharmacy visit, while 28% of children had seen between one and four different health professionals. The cost to the NHS of children contacting health professionals outside dentistry was £36 573, extrapolated to an annual cost of £373 288. Replicating these findings across all pharmacies in England could mean that the NHS spends an estimated £2.3 million annually when children with oral pain inappropriately use multiple health services.ConclusionMost parents who visited pharmacies for children’s pain medications in London sought pain medications for children’s oral pain. Children’s inappropriate contact with multiple health services when they have oral pain adds significant costs to the NHS.
Remission and low disease activity in systemic lupus erythematosus: an achievable goal even with fewer steroids? Real-life data from a monocentric cohort
Authors: Tani Chiara , Vagelli Roberta , Stagnaro Chiara , Carli Linda , Mosca Marta 
Published: March 2018

ObjectivesTo evaluate what proportion of patients fulfil the DORIS definition of remission, the definition of lupus low disease activity state (LLDAS) and LLDAS with a glucocorticoid (GC) dosage ≤5 (LLDAS5) in a longitudinal monocentric cohort of patients with SLE; to identify predictors of sustained remission and LLDAS attainment; to evaluate the effect of sustained remission and LLDAS on damage accrual over a period of 5 years and compare the two conditions in terms of clinical outcomes.MethodsRetrospective analysis of data prospectively collected from patients with SLE followed from 2012 to 2016.Results115 patients were included in this analysis. At baseline, 72% of patients were on LLDAS and almost all patients also fulfilled the LLDAS5 definition; 45% of patients were in remission on treatment, 12% were in remission off treatment, 26% were in complete remission on treatment, 2% were in complete remission off treatment. Disease activity at baseline was the strongest predictor of subsequent LLDAS and remission; the presence of joint and cutaneous manifestations was associated with a minor likelihood to achieve LLDAS or remission during follow-up.Patients in remission and LLDAS for the whole follow-up period accrued significantly less organ damage; on the contrary, patients who maintained all kinds of remissions or LLDAS for less than 50% of the time did not show any differences in damage accrual with respect to the rest of the cohort.ConclusionRemission and LLDAS, even with reduced GC use, are an achievable goal in clinical practice; sustained LLDAS and remission are both associated with reduced damage accrual.
Determining resolution of Angiostrongylus vasorum in dogs following anthelmintic treatment with an imidacloprid 10 per cent/moxidectin 2.5 per cent spot‐on
Authors: Bird Louise Elizabeth , Bilbrough Graham , Fitzgerald Ronan , Walker David John 
Published: March 2018

ObjectivesTo determine the time from treatment with a product containing imidacloprid 10 per cent/moxidectin 2.5 per cent spot‐on (Advocate™), to dogs becoming negative for Angiostrongylus vasorum (A. vasorum). The authors hypothesised that most dogs would have resolution of A. vasorum within four weeks of treatment with Advocate™.DesignProspective, non‐randomised, prepost treatment study.SettingCases were enrolled from general practices along the southern coast of the United Kingdom.ParticipantsNine dogs completed the study and were enrolled if A. vasorum had been diagnosed based on a positive commercially available, in‐clinic, serological A. vasorum antigen test (Angio Detect®) or Baermann performed at an external laboratory or both.InterventionsThe only treatment A. vasorum‐positive dogs received was Advocate™ which was applied at the time of diagnosis and reapplied if necessary at four‐weekly intervals until dogs tested negative by Angio Detect.Primary outcome measuresAngio Detect® was performed and Advocate™ was reapplied at four‐weekly intervals until dogs tested negative by this method.Secondary outcome measuresBaermann was also performed at four‐weekly intervals until dogs tested negative by this method.ResultsApplication of Advocate™ was an effective treatment for A. vasorum infection in dogs and resulted in resolution of the infection, based on Angio Detect® testing and Baermann, within four weeks, in eight out of nine dogs. Post‐treatment Angio Detect® testing was concordant with Baermann in seven of nine dogs.ConclusionsApplication of Advocate™ was an effective treatment for A. vasorum infection in dogs and resulted in resolution of the infection within four weeks in most dogs. Repeat Angio Detect® testing is recommended following treatment of A. vasorum to confirm resolution of the infection.
The impact of short-chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon
Authors: Christiansen Charlotte Bayer , Gabe Maria Buur Nordskov , Svendsen Berit , Dragsted Lars Ove , Rosenkilde Mette Marie , Holst Jens Juul 
Published: March 2018

The colonic epithelium harbors a large number of endocrine cells, but little is known about the endocrine functions of the colon. However, the high density of glucagon like peptide-1 (GLP-1)- and peptide-YY (PYY)-secreting L cells is of great interest because of the potential antidiabetic and antiobesity effects of GLP-1 and PYY. Short-chain fatty acids (SCFAs) produced by local bacterial fermentation are suggested to activate the colonic free fatty acid receptors FFAR2 (GPR43) and FFAR3 (GPR41), stimulating the colonic L cells. We used the isolated perfused rat colon as a model of colonic endocrine secretion and studied the effects of the predominant SCFAs formed: acetate, propionate, and butyrate. We show that luminal and especially vascular infusion of acetate and butyrate significantly increases colonic GLP-1 secretion, and to a minor extent also PYY secretion, but only after enhancement of intracellular cAMP. Propionate neither affected GLP-1 nor PYY secretion whether administered luminally or vascularly. A FFAR2- and FFAR3–specific agonist [( S)-2-(4-chlorophenyl)-3,3-dimethyl- N-(5-phenylthiazol-2-yl)butamide (CFMB)/ AR420626 ] had no effect on colonic GLP-1 output, and a FFAR3 antagonist ( AR399519 ) did not decrease the SCFA-induced GLP-1 response. However, the voltage-gated Ca2+-channel blocker nifedipine, the KATP-channel opener diazoxide, and the ATP synthesis inhibitor 2,4-dinitrophenol completely abolished the responses. FFAR2 receptor studies confirmed low-potent partial agonism of acetate, propionate, and butyrate, compared with CFMB, which is a full agonist with ~750-fold higher potency than the SCFAs. In conclusion, SCFAs may increase colonic GLP-1/PYY secretion, but FFAR2/FFAR3 do not seem to be involved. Rather, SCFAs are metabolized and appear to function as a colonocyte energy source.NEW & NOTEWORTHY By the use of in situ isolated perfused rat colon we show that short-chain fatty acids (SCFAs) primarily are used as a colonocyte energy source in the rat, subsequently triggering glucagon like peptide-1 (GLP-1) secretion independent of the free fatty acid receptors FFAR2 and FFAR3. Opposite many previous studies on SCFAs and FFAR2/FFAR3 and GLP-1 secretion, this experimental model allows investigation of the physiological interactions between luminal nutrients and secretion from cells whose function depend critically on their blood supply as well as nerve and paracrine interactions.