Interlaboratory comparison of size measurements on nanoparticles using nanoparticle tracking analysis (NTA)

One of the key challenges in the field of nanoparticle (NP) analysis is in producing reliable and reproducible characterisation data for nanomaterials. This study looks at the reproducibility using a relatively new, but rapidly adopted, technique, Nanoparticle Tracking Analysis (NTA) on a range of particle sizes and materials in several different media. It describes the protocol development and presents both the data and analysis of results obtained from 12 laboratories, mostly based in Europe, who are primarily QualityNano members. QualityNano is an EU FP7 funded Research Infrastructure that integrates 28 European analytical and experimental facilities in nanotechnology, medicine and natural sciences with the goal of developing and implementing best practice and quality in all aspects of nanosafety assessment. This study looks at both the development of the protocol and how this leads to highly reproducible results amongst participants. In this study, the parameter being measured is the modal particle size.

Maturation of lymph node fibroblastic reticular cells from myofibroblastic precursors is critical for antiviral immunity.

The stromal scaffold of the lymph node (LN) paracortex is built by fibroblastic reticular cells (FRCs). Conditional ablation of lymphotoxin-β receptor (LTβR) expression in LN FRCs and their mesenchymal progenitors in developing LNs revealed that LTβR-signaling in these cells was not essential for the formation of LNs. Although T cell zone reticular cells had lost podoplanin expression, they still formed a functional conduit system and showed enhanced expression of myofibroblastic markers. However, essential immune functions of FRCs, including homeostatic chemokine and interleukin-7 expression, were impaired. These changes in T cell zone reticular cell function were associated with increased susceptibility to viral infection. Thus, myofibroblasic FRC precursors are able to generate the basic T cell zone infrastructure, whereas LTβR-dependent maturation of FRCs guarantees full immunocompetence and hence optimal LN function during infection.

Prólogo: Hombres escritos por mujeres

La lucha política del feminismo partió de las mujeres y para las mujeres, y excluyó inicialmente a los hombres, ya que representaban el sujeto visible de las instituciones patriarcales. En la literatura escrita por mujeres, esto significó tanto la crítica a las imágenes femeninas estereotipadas que presentaban muchas de las obras consideradas «universales», como la configuración de heroínas distintas, más complejas y «positivas» que sirvieran de modelo a las mujeres reales para elaborar nuevos códigos de conducta y de relación con los hombres. Sin embargo, a medida que las reivindicaciones del feminismo se fueron afirmando, este primer paso dejó de ser necesario y, actualmente, incluso las autoras feministas dedican tanta atención a los personajes masculinos como a los femeninos, huyendo de los tópicos, tanto antiguos como nuevos. Los ensayos del presente volumen parten de la consideración del discurso literario como un espacio privilegiado de la construcción y deconstrucción de los géneros. Analizan personajes masculinos escritos por mujeres pertenecientes a épocas y culturas distintas, desde Madame de Lafayette en la Francia del s. XVII a las jóvenes autoras gallegas del s. XXI. Dichos personajes, tanto los de ficción como los que se basan en personas reales (como Sartre, «escrito» por Simone de Beauvoir, o Picasso, por Gertrude Stein) son también complejos, matizados, e incluso contradictorios, es decir, irreductibles a una única perspectiva.

Prólogo: Hombres escritos por mujeres

La lucha política del feminismo partió de las mujeres y para las mujeres, y excluyó inicialmente a los hombres, ya que representaban el sujeto visible de las instituciones patriarcales. En la literatura escrita por mujeres, esto significó tanto la crítica a las imágenes femeninas estereotipadas que presentaban muchas de las obras consideradas «universales», como la configuración de heroínas distintas, más complejas y «positivas» que sirvieran de modelo a las mujeres reales para elaborar nuevos códigos de conducta y de relación con los hombres. Sin embargo, a medida que las reivindicaciones del feminismo se fueron afirmando, este primer paso dejó de ser necesario y, actualmente, incluso las autoras feministas dedican tanta atención a los personajes masculinos como a los femeninos, huyendo de los tópicos, tanto antiguos como nuevos. Los ensayos del presente volumen parten de la consideración del discurso literario como un espacio privilegiado de la construcción y deconstrucción de los géneros. Analizan personajes masculinos escritos por mujeres pertenecientes a épocas y culturas distintas, desde Madame de Lafayette en la Francia del s. XVII a las jóvenes autoras gallegas del s. XXI. Dichos personajes, tanto los de ficción como los que se basan en personas reales (como Sartre, «escrito» por Simone de Beauvoir, o Picasso, por Gertrude Stein) son también complejos, matizados, e incluso contradictorios, es decir, irreductibles a una única perspectiva.

Prólogo: Hombres escritos por mujeres

La lucha política del feminismo partió de las mujeres y para las mujeres, y excluyó inicialmente a los hombres, ya que representaban el sujeto visible de las instituciones patriarcales. En la literatura escrita por mujeres, esto significó tanto la crítica a las imágenes femeninas estereotipadas que presentaban muchas de las obras consideradas «universales», como la configuración de heroínas distintas, más complejas y «positivas» que sirvieran de modelo a las mujeres reales para elaborar nuevos códigos de conducta y de relación con los hombres. Sin embargo, a medida que las reivindicaciones del feminismo se fueron afirmando, este primer paso dejó de ser necesario y, actualmente, incluso las autoras feministas dedican tanta atención a los personajes masculinos como a los femeninos, huyendo de los tópicos, tanto antiguos como nuevos. Los ensayos del presente volumen parten de la consideración del discurso literario como un espacio privilegiado de la construcción y deconstrucción de los géneros. Analizan personajes masculinos escritos por mujeres pertenecientes a épocas y culturas distintas, desde Madame de Lafayette en la Francia del s. XVII a las jóvenes autoras gallegas del s. XXI. Dichos personajes, tanto los de ficción como los que se basan en personas reales (como Sartre, «escrito» por Simone de Beauvoir, o Picasso, por Gertrude Stein) son también complejos, matizados, e incluso contradictorios, es decir, irreductibles a una única perspectiva.

Changes in the use of broad-spectrum antibiotics after cefepime shortage: a time series analysis.

The original cefepime product was withdrawn from the Swiss market in January 2007, and replaced by a generic 10 months later. The goals of the study were to assess the impact of this cefepime shortage on the use and costs of alternative broad-spectrum antibiotics, on antibiotic policy, and on resistance of Pseudomonas aeruginosa towards carbapenems, ceftazidime and piperacillin-tazobactam. A generalized regression-based interrupted time series model assessed how much the shortage changed the monthly use and costs of cefepime and of selected alternative broad-spectrum antibiotics (ceftazidime, imipenem-cilastatin, meropenem, piperacillin-tazobactam) in 15 Swiss acute care hospitals from January 2005 to December 2008. Resistance of P. aeruginosa was compared before and after the cefepime shortage. There was a statistically significant increase in the consumption of piperacillin-tazobactam in hospitals with definitive interruption of cefepime supply, and of meropenem in hospitals with transient interruption of cefepime supply. Consumption of each alternative antibiotic tended to increase during the cefepime shortage and to decrease when the cefepime generic was released. These shifts were associated with significantly higher overall costs. There was no significant change in hospitals with uninterrupted cefepime supply. The alternative antibiotics for which an increase in consumption showed the strongest association with a progression of resistance were the carbapenems. The use of alternative antibiotics after cefepime withdrawal was associated with a significant increase in piperacillin-tazobactam and meropenem use and in overall costs, and with a decrease in susceptibility of P. aeruginosa in hospitals. This warrants caution with regard to shortages and withdrawals of antibiotics.

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Polymorphisms in Toll-like receptor 9 influence the clinical course of HIV-1 infection.

BACKGROUND: The clinical course of HIV-1 infection is highly variable among individuals, at least in part as a result of genetic polymorphisms in the host. Toll-like receptors (TLRs) have a key role in innate immunity and mutations in the genes encoding these receptors have been associated with increased or decreased susceptibility to infections. OBJECTIVES: To determine whether single-nucleotide polymorphisms (SNPs) in TLR2-4 and TLR7-9 influenced the natural course of HIV-1 infection. METHODS: Twenty-eight SNPs in TLRs were analysed in HAART-naive HIV-positive patients from the Swiss HIV Cohort Study. The SNPs were detected using Sequenom technology. Haplotypes were inferred using an expectation-maximization algorithm. The CD4 T cell decline was calculated using a least-squares regression. Patients with a rapid CD4 cell decline, less than the 15th percentile, were defined as rapid progressors. The risk of rapid progression associated with SNPs was estimated using a logistic regression model. Other candidate risk factors included age, sex and risk groups (heterosexual, homosexual and intravenous drug use). RESULTS: Two SNPs in TLR9 (1635A/G and +1174G/A) in linkage disequilibrium were associated with the rapid progressor phenotype: for 1635A/G, odds ratio (OR), 3.9 [95% confidence interval (CI),1.7-9.2] for GA versus AA and OR, 4.7 (95% CI,1.9-12.0) for GG versus AA (P = 0.0008). CONCLUSION: Rapid progression of HIV-1 infection was associated with TLR9 polymorphisms. Because of its potential implications for intervention strategies and vaccine developments, additional epidemiological and experimental studies are needed to confirm this association.

Influence of HLA-C expression level on HIV control.

A variant upstream of human leukocyte antigen C (HLA-C) shows the most significant genome-wide effect on HIV control in European Americans and is also associated with the level of HLA-C expression. We characterized the differential cell surface expression levels of all common HLA-C allotypes and tested directly for effects of HLA-C expression on outcomes of HIV infection in 5243 individuals. Increasing HLA-C expression was associated with protection against multiple outcomes independently of individual HLA allelic effects in both African and European Americans, regardless of their distinct HLA-C frequencies and linkage relationships with HLA-B and HLA-A. Higher HLA-C expression was correlated with increased likelihood of cytotoxic T lymphocyte responses and frequency of viral escape mutation. In contrast, high HLA-C expression had a deleterious effect in Crohn's disease, suggesting a broader influence of HLA expression levels in human disease.

Indications for cardiovascular magnetic resonance in children with congenital and acquired heart disease: an expert consensus paper of the Imaging Working Group of the AEPC and the Cardiovascular Magnetic Resonance Section of the EACVI.

This article provides expert opinion on the use of cardiovascular magnetic resonance (CMR) in young patients with congenital heart disease (CHD) and in specific clinical situations. As peculiar challenges apply to imaging children, paediatric aspects are repeatedly discussed. The first section of the paper addresses settings and techniques, including the basic sequences used in paediatric CMR, safety, and sedation. In the second section, the indication, application, and clinical relevance of CMR in the most frequent CHD are discussed in detail. In the current era of multimodality imaging, the strengths of CMR are compared with other imaging modalities. At the end of each chapter, a brief summary with expert consensus key points is provided. The recommendations provided are strongly clinically oriented. The paper addresses not only imagers performing CMR, but also clinical cardiologists who want to know which information can be obtained by CMR and how to integrate it in clinical decision-making.

Polychlorinated and polybrominated biphenyls

This volume of the IARC Monographs provides evaluations of the carcinogenicity of polychlorinated biphenyls and polybrominated biphenyls. Polychlorinated biphenyls are a class of aromatic compounds comprising 209 congeners, each containing 1 to 10 chlorine atoms attached to a biphenyl nucleus. Technical products, which were manufactured to obtain a certain degree of chlorination, are mixtures of numerous congeners. These products were widely used as dielectric fluid in capacitors and transformers, and to a lesser extent in building materials. Although their production and use has been banned in most countries, these compounds are ubiquitous environmental pollutants, including in polar regions and the deep ocean, because they are persistent and bioaccumulate. Worldwide monitoring programmes have shown that polychlorinated biphenyls are present in most samples of human milk. An IARC Monographs Working Group reviewed epidemiological evidence, animal bioassays, and mechanistic and other relevant data to reach conclusions as to the carcinogenic hazard to humans of polychlorinated biphenyls, of the subclass of dioxinlike polychlorinated biphenyls, and of polybrominated biphenyls.