460 research outputs found
Pilus distribution among lineages of group b <i>streptococcus</i>: an evolutionary and clinical perspective
<b>Background</b><p></p>
Group B Streptococcus (GBS) is an opportunistic pathogen in both humans and bovines. Epidemiological and phylogenetic analyses have found strains belonging to certain phylogenetic lineages to be more frequently associated with invasive newborn disease, asymptomatic maternal colonization, and subclinical bovine mastitis. Pilus structures in GBS facilitate colonization and invasion of host tissues and play a role in biofilm formation, though few large-scale studies have estimated the frequency and diversity of the three pilus islands (PIs) across diverse genotypes. Here, we examined the distribution of pilus islands (PI) 1, 2a and 2b among 295 GBS strains representing 73 multilocus sequence types (STs) belonging to eight clonal complexes. PCR-based RFLP was also used to evaluate variation in the genes encoding pilus backbone proteins of PI-2a and PI-2b.<p></p>
<b>Results</b><p></p>
All 295 strains harbored one of the PI-2 variants and most human-derived strains contained PI-1. Bovine-derived strains lacked PI-1 and possessed a unique PI-2b backbone protein allele. Neonatal strains more frequently had PI-1 and a PI-2 variant than maternal colonizing strains, and most CC-17 strains had PI-1 and PI-2b with a distinct backbone protein allele. Furthermore, we present evidence for the frequent gain and loss of genes encoding certain pilus types.<p></p>
<b>Conclusions</b><p></p>
These data suggest that pilus combinations impact host specificity and disease presentation and that diversification often involves the loss or acquisition of PIs. Such findings have implications for the development of GBS vaccines that target the three pilus islands
Sources and nature of ice-nucleating particles in the free troposphere at Jungfraujoch in winter 2017
Primary ice formation in mixed-phase clouds is initiated by a
minute subset of the ambient aerosol population, called ice-nucleating
particles (INPs). The knowledge about their atmospheric concentration,
composition, and source in cloud-relevant environments is still limited.
During the 2017 joint INUIT/CLACE (Ice Nuclei research UnIT/CLoud–Aerosol
Characterization Experiment) field campaign, observations of INPs as
well as of aerosol physical and chemical properties were performed,
complemented by source region modeling. This aimed at investigating the
nature and sources of INPs. The campaign took place at the High-Altitude
Research Station Jungfraujoch (JFJ), a location where mixed-phase clouds
frequently occur. Due to its altitude of 3580 m a.s.l., the station is
usually located in the lower free troposphere, but it can also receive air
masses from terrestrial and marine sources via long-range transport. INP
concentrations were quasi-continuously detected with the Horizontal Ice
Nucleation Chamber (HINC) under conditions representing the formation of
mixed-phase clouds at −31 ∘C. The INP measurements were performed
in parallel to aerosol measurements from two single-particle mass
spectrometers, the Aircraft-based Laser ABlation Aerosol MAss Spectrometer
(ALABAMA) and the laser ablation aerosol particle time-of-flight mass
spectrometer (LAAPTOF). The chemical identity of INPs is inferred by
correlating the time series of ion signals measured by the mass
spectrometers with the time series of INP measurements. Moreover, our
results are complemented by the direct analysis of ice particle residuals
(IPRs) by using an ice-selective inlet (Ice-CVI) coupled with the ALABAMA.
Mineral dust particles and aged sea spray particles showed the highest
correlations with the INP time series. Their role as INPs is further
supported by source emission sensitivity analysis using atmospheric
transport modeling, which confirmed that air masses were advected from the
Sahara and marine environments during times of elevated INP
concentrations and ice-active surface site densities. Indeed, the IPR
analysis showed that, by number, mineral dust particles dominated the IPR
composition (∼58 %), and biological and metallic
particles are also found to a smaller extent (∼10 % each). Sea
spray particles are also found as IPRs (17 %), and their fraction in the
IPRs strongly varied according to the increased presence of small IPRs,
which is likely due to an impact from secondary ice crystal formation. This
study shows the capability of combining INP concentration measurements with
chemical characterization of aerosol particles using single-particle mass
spectrometry, source region modeling, and analysis of ice residuals in an
environment directly relevant for mixed-phase cloud formation.</p
Genetic Diversity and Virulence Potential of Shiga Toxin-Producing Escherichia coli O113:H21 Strains Isolated from Clinical, Environmental, and Food Sources
Shiga toxin-producing Escherichia coli strains of serotype O113:H21 have caused severe human diseases, but they are unusual in that they do not produce adherence factors coded by the locus of enterocyte effacement. Here, a PCR microarray was used to characterize 65 O113:H21 strains isolated from the environment, food, and clinical infections from various countries. in comparison to the pathogenic strains that were implicated in hemolytic-uremic syndrome in Australia, there were no clear differences between the pathogens and the environmental strains with respect to the 41 genetic markers tested. Furthermore, all of the strains carried only Shiga toxin subtypes associated with human infections, suggesting that the environmental strains have the potential to cause disease. Most of the O113:H21 strains were closely related and belonged in the same clonal group (ST-223), but CRISPR analysis showed a great degree of genetic diversity among the O113:H21 strains.French Joint Ministerial Program of R&D against CBRNE RisksFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Food & Drug Adm, Div Microbiol, College Pk, MD 20740 USAFrench Agcy Food Environm & Occupat Hlth & Safety, Lab Food Safety, Maisons Alfort, FranceFood & Drug Adm, Div Mol Biol, Laurel, MD USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFed Inst Risk Assessment, Natl Reference Lab Escherichia coli, Berlin, GermanyInst Nacl Enfermedades Infecciosas ANLIS Dr Carlo, Serv Fisiopatogenia, Buenos Aires, DF, ArgentinaUniv Melbourne, Peter Doherty Inst Infect & Immun, Dept Microbiol & Immunol, Melbourne, Vic, AustraliaUniv Adelaide, Res Ctr Infect Dis, Sch Mol & Biomed Sci, Adelaide, SA, AustraliaUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFrench Joint Ministerial Program of R&D against CBRNE Risks: C17609-2Web of Scienc
Surgical Management of Pediatric Inguinal Hernia: A Systematic Review and Guideline from the European Pediatric Surgeons' Association Evidence and Guideline Committee
Introduction: Inguinal hernia repair represents the most common operation in childhood; however, consensus about the optimal management is lacking. Hence, recommendations for clinical practice are needed. This study assesses the available evidence and compiles recommendations on pediatric inguinal hernia. /
Materials and Methods: The European Pediatric Surgeons' Association Evidence and Guideline Committee addressed six questions on pediatric inguinal hernia repair with the following topics: (1) open versus laparoscopic repair, (2) extraperitoneal versus transperitoneal repair, (3) contralateral exploration, (4) surgical timing, (5) anesthesia technique in preterm infants, and (6) operation urgency in girls with irreducible ovarian hernia. Systematic literature searches were performed using PubMed, MEDLINE, Embase (Ovid), and The Cochrane Library. Reviews and meta-analyses were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. /
Results: Seventy-two out of 5,173 articles were included, 27 in the meta-analyses. Laparoscopic repair shortens bilateral operation time compared with open repair. In preterm infants, hernia repair after neonatal intensive care unit (NICU)/hospital discharge is associated with less respiratory difficulties and recurrences, regional anesthesia is associated with a decrease of postoperative apnea and pain. The review regarding operation urgency for irreducible ovarian hernia gained insufficient evidence of low quality. /
Conclusion: Laparoscopic repair may be beneficial for children with bilateral hernia and preterm infants may benefit using regional anesthesia and postponing surgery. However, no definite superiority was found and available evidence was of moderate-to-low quality. Evidence for other topics was less conclusive. For the optimal management of inguinal hernia repair, a tailored approach is recommended taking into account the local facilities, resources, and expertise of the medical team involved
Social democracy, embeddedness and decommodification: On the conceptual innovations and intellectual affiliations of Karl Polanyi
Of the several debates that revolve around the work of the economic historian and political economist Karl Polanyi, one that continues to exercise minds concerns his analysis of, and political attitudes toward, post-war capitalism and the welfare state. Simplified a little, it is a debate with two sides. To borrow Iván Szelényi's terms, one side constructs a ‘hard’ Karl Polanyi, the other a ‘soft’ one. The former advocated a socialist mixed economy dominated by redistributive mechanisms. He was a radical socialist for whom the market should never be the dominant mechanism of economic coordination. His ‘soft’ alter ego insisted that the market system remain essentially intact but be complemented by redistributive mechanisms. The ‘double movement’ – the central thesis of his ‘Great Transformation’ – acts, in this reading, as a self-correcting mechanism that moderates the excesses of market fundamentalism; its author was positioned within the social-democratic mainstream for which the only realistic desirable goal is a regulated form of capitalism. In terms of textual evidence there is much to be said for both interpretations. In this article I suggest a different approach, one that focuses upon the meaning of Polanyi's concepts in relation to their socio-political and intellectual environment
Treatment Strategies and Outcome of the Exstrophy–Epispadias Complex in Germany: Data From the German CURE-Net
Introduction: To evaluate the impact of reconstructive strategies and post-operative management on short- and long-term surgical outcome and complications of classical bladder exstrophy (CBE) patients' comprehensive data of the multicenter German-wide Network for Congenital Uro-Rectal malformations (CURE-Net) were analyzed.
Methods: Descriptive analyses were performed between 34 prospectively collected CBE patients born since 2009, median 3 months old [interquartile range (IQR), 2–4 months], and 113 cross-sectional patients, median 12 years old (IQR, 6–21 years).
Results: The majority of included individuals were males (67%). Sixty-eight percent of the prospectively observed and 53% of the cross-sectional patients were reconstructed using a staged approach (p = 0.17). Although prospectively observed patients were operated on at a younger age, the post-operative management did not significantly change in the years before and after 2009. Solely, in prospectively observed patients, peridural catheters were used significantly more often (p = 0.017). Blood transfusions were significantly more frequent in males (p = 0.002). Only half of all CBE individuals underwent inguinal hernia repair. Cross-sectional patients after single-stage reconstructions showed more direct post-operative complications such as upper urinary tract dilatations (p = 0.0021) or urinary tract infections (p = 0.023), but not more frequent renal function impairment compared to patients after the staged approach (p = 0.42). Continence outcomes were not significantly different between the concepts (p = 0.51). Self-reported continence data showed that the majority of the included CBE patients was intermittent or continuous incontinent. Furthermore, subsequent consecutive augmentations and catheterizable stomata did not significantly differ between the two operative approaches. Urinary diversions were only reported after the staged concept.
Conclusions: In this German multicenter study, a trend toward the staged concept was observed. While single-stage approaches tended to have initially more complications such as renal dilatation or urinary tract infections, additional surgery such as augmentations and stomata appeared to be similar after staged and single-stage reconstructions in the long term
Minimal knotted polygons in cubic lattices
An implementation of BFACF-style algorithms on knotted polygons in the simple
cubic, face centered cubic and body centered cubic lattice is used to estimate
the statistics and writhe of minimal length knotted polygons in each of the
lattices. Data are collected and analysed on minimal length knotted polygons,
their entropy, and their lattice curvature and writhe
Laboratory and field studies of ice-nucleating particles from open-lot livestock facilities in Texas
In this work, an abundance of ice-nucleating particles (INPs) from livestock
facilities was studied through laboratory measurements from cloud-simulation chamber experiments and field investigation in the Texas Panhandle. Surface
materials from two livestock facilities, one in the Texas Panhandle and
another from McGregor, Texas, were selected as dust proxies for laboratory
analyses. These two samples possessed different chemical and biological
properties. A combination of aerosol interaction and dynamics in the
atmosphere (AIDA) measurements and offline ice spectrometry was used to
assess the immersion freezing mode ice nucleation ability and efficiency of
these proxy samples at temperatures above −29 ∘C. A dynamic
filter processing chamber was also used to complement the freezing
efficiencies of submicron and supermicron particles collected from the AIDA
chamber. For the field survey, periodic ambient particle sampling took place
at four commercial livestock facilities from July 2017 to July 2019. INP
concentrations of collected particles were measured using an offline
freezing test system, and the data were acquired for temperatures between −5 and −25 ∘C.
Our AIDA laboratory results showed that the freezing spectra of two
livestock dust proxies exhibited higher freezing efficiency than previously
studied soil dust samples at temperatures below −25 ∘C. Despite
their differences in composition, the freezing efficiencies of both proxy
livestock dust samples were comparable to each other. Our dynamic filter
processing chamber results showed on average approximately 50 %
supermicron size dominance in the INPs of both dust proxies. Thus, our
laboratory findings suggest the importance of particle size in immersion
freezing for these samples and that the size might be a more important factor for immersion freezing of livestock dust than the composition. From a
3-year field survey, we measured a high concentration of ambient INPs of 1171.6 ± 691.6 L−1 (average ± standard error) at −25 ∘C for aerosol particles collected at the downwind edges of
livestock facilities. An obvious seasonal variation in INP concentration,
peaking in summer, was observed, with the maximum at the same temperature exceeding 10 000 L−1 on 23 July 2018. The observed high INP
concentrations suggest that a livestock facility is a substantial source of
INPs. The INP concentration values from our field survey showed a strong
correlation with measured particulate matter mass concentration, which
supports the importance of size in ice nucleation of particles from
livestock facilities.</p
RNA interference-mediated knockdown of p21WAF1 enhances anti-tumor cell activity of oncolytic adenoviruses
The ability of oncolytic adenoviruses to replicate in and lyse cancer cells offers a potential therapeutic approach. However, selectivity and efficacy of adenovirus replication need to be improved. In this study, we present that loss of p21WAF1 promotes adenovirus replication and more effective cell killing. To test our hypothesis, we took HCT116 colon cancer cell lines carrying deletions of either p21WAF1 or p53, and infected these cell lines with wild-type adenovirus (WtD) or the oncolytic adenoviruses, ONYX-015 and Delta-24. We found that WtD, ONYX-015 and Delta-24 induced stronger cytopathic effects in HCT116 p21−/− cells compared with HCT116-WT cells. This was accompanied by increased virus production. siRNA-mediated knockdown of p21WAF1, and similarly of p27KIP1, in HCT116-WT cells also enhanced replication of and cell killing by these viruses. Furthermore, we found that TE7, an esophageal carcinoma cell line, also showed a strong cell-killing effect and virus production when p21WAF1 expression was suppressed by RNA interference before adenoviruses infection. Also, H1299 and DU-145 cells transfected with p21WAF1 siRNA showed higher virus production after ONYX-015 and Delta-24 infections. These observations suggest that p21WAF1 plays a role in mediating replication of oncolytic viruses with potential implications for adenoviral therapy of cancer
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