[Transbronchial lung cryobiopsy in interstitial lung diseases]

In some cases of interstitial lung disease (ILD), clinical and biological findings associated with CT scan pattern during multidisciplinary discussion (MDD) fail to yield a confident diagnosis. In these cases, histology may be necessary. Transbronchial lung cryobiopsy (TBLC) is a bronchoscopic procedure that has been developed in recent years and currently contributes to diagnostic work-up in patients with ILD. TBLC provides tissue samples for histological analysis with an acceptable risk of complications, consisting mainly in pneumothorax or bleeding. In addition to higher diagnostic yield than conventional forceps biopsies, the procedure shows a better safety profile than surgical biopsies. The indication to perform TBLC is decided during a 1st MDD and during a 2nd MDD, results can provide a diagnostic yield approximating 80%. TBLC appears to be an attractive, minimally invasive technique to be proposed as a first-line procedure in selected patients in experienced centers, while surgical lung biopsy may be considered as a second-line solution.

DNA polymerase δ: A single Pol31 polymorphism suppresses the strain background-specific lethality of Pol32 inactivation in Saccharomyces cerevisiae

The evolutionarily conserved DNA polymerase delta (Polδ) plays several essential roles in eukaryotic DNA replication and repair, responsible for the synthesis of the lagging-strand, lower replicative mutagenesis via its proof-reading exonuclease activity and synthetizes both strands during break-induced replication. In Saccharomyces cerevisiae, the Polδ protein complex consists of three subunits encoded by the POL3, POL31 and POL32 genes. Surprisingly, in contrast to POL3 and POL31, the POL32 gene deletion was found to be viable but lethal in all other eukaryotes, raising the question to which extent the viability of the POL32 deletion in S. cerevisiae was species specific. To address this issue, we inactivated the POL32 gene in 10 evolutionary close or distant S. cerevisiae strains and found that POL32 was either essential (3 strains including SK1), non-essential (5 strains including the reference S288C strain) or confers a slow-growth phenotype (2 strains). Whole-genome sequencing of S288C/SK1 pol32∆ meiotic segregants identified the lethal/suppressor effect of the single Pol31-C43Y polymorphism. Consistently, the introduction of the Pol31-43C allele in the SK1 and West African (WA) pol32∆ mutants was sufficient to restore cell viability and wild-type growth upon introduction of two copies of POL31-43C in the SK1 haploid strain. Reciprocally, introduction of the SK1 POL31-43Y allele in the S288C pol32∆ mutant was lethal. Sequence analyses of the POL31 polymorphisms in the 1,011 yeasts genome dataset correlates with the strict occurrence of the POL31-43Y allele in the yeast African palm wine clade. Differently, the single Pol31-E400G polymorphism confers pol32∆ lethality in the Malaysian strain. In the yeast two-hybrid assay, we observed a weakened interaction between Pol3 and Pol31-43Y versus Pol31-43C suggesting an insufficient level of the Polδ holoenzyme stability/activity. Thus, the enigmatic non-essentiality of Pol32 in S. cerevisiae results from single Pol31 amino acid polymorphism and is clade rather than species specific.

[Impact of disease on daily activities, emotions and quality of life of patients with hereditary angioedema]

INTRODUCTION

Hereditary angioedema (HAE) is characterized by recurrent attacks of swelling of various locations and severity. An impaired quality of life of patients with HAE has been reported by several studies. We aimed at examining the overall impact of the disease in patients followed for type I HAE, particularly its impact on daily life activities, emotions and quality of life.

METHODS

A questionnaire was distributed to patients consulting for type I HAE, collecting demographics, disease characteristics, impact on professional life, Hospital Anxiety and Depression score (HAD), SF-36 score and the McMaster Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR).

RESULTS

The 33 patients included reported an average of 5.17 attacks over the last year. Stress was the main trigger A long-term treatment was reported by 58% of patients, 72% received specific treatment in the event of a serious attack. Sick days were reported by 33% of patients during their studies, and by 34% during work. One patient suffered from depressive symptoms and ten from anxious symptoms, according to the HAD score. The areas most impacted on the SF-36 score were general health and vitality. The mean score for MACTAR was low.

CONCLUSION

HAE still has a significant impact on the daily and emotional lives of patients, despite the availability of prophylactic and crisis treatments.

High throughput transepithelial electrical resistance (TEER) measurements on perfused membrane-free epithelia

Assessment of epithelial barrier function is critically important for studying healthy and diseased biological models. Here we introduce an instrument that measures transepithelial electrical resistance (TEER) of perfused epithelial tubes in the microfluidic OrganoPlate platform. The tubules are grown in microfluidic channels directly against an extracellular matrix, obviating the need for artificial filter membranes. We present TEER measurements on Caco-2 intestinal and renal proximal tubule epithelium. Forty tubules on one single plate were interrogated in less than a minute. We show that TEER measurement is significantly more sensitive than a fluorescent reporter leakage assay in response to staurosporine. We demonstrate a 40-channel time-lapse data acquisition over a 25 hour time period under flow conditions. We furthermore observed a 50% reduction in Caco-2 TEER values following exposure to a cocktail of inflammatory cytokines. To our best knowledge, this is the first instrument of its kind that allows routine TEER studies in perfused organ-on-a-chip systems without interference by artificial filter membranes. We believe the apparatus will contribute to accelerating routine adoption of perfused organ-on-a-chip systems in academic research and in industrial drug development.

Dairy consumption is associated with lower plasma dihydroceramides in women from the D.E.S.I.R. cohort

AIM

In the D.E.S.I.R. cohort, higher consumption of dairy products was associated with lower incidence of hyperglycaemia, and dihydroceramide concentrations were higher in those who progressed to diabetes. Our aim here was to study the relationships between dairy consumption and concentrations of dihydroceramides and ceramides.

METHODS

In the D.E.S.I.R. cohort, men and women aged 30-65 years, volunteers from West-Central France, were included in a 9-year follow-up with examinations every 3 years, including food-frequency questionnaires. Two items concerned dairy products (cheese, other dairy products except cheese). At each examination, dihydroceramides and ceramides were determined by mass spectrometry in a cohort subset; in the present study, the 105 people who did not progress to type 2 diabetes were analyzed, as the disorder per se might be a confounding factor.

RESULTS

Higher consumption of dairy products (except cheese) was associated with total plasma dihydroceramides during the follow-up, but only in women (P=0.01 for gender interaction). In fact, dihydroceramide levels were lower in women with high vs low consumption (P=0.03), and were significantly increased during follow-up (P=0.01) in low consumers only. There was also a trend for lower ceramides in women with high dairy (except cheese) intakes (P=0.08). Cheese was associated with dihydroceramide and ceramide changes during follow-up (P=0.04 for both), but no clear trend was evident in either low or high consumers.

CONCLUSION

These results show that, in women, there is an inverse association between fresh dairy product consumption and predictive markers (dihydroceramides) of type 2 diabetes.

Are circadian rhythms new pathways to understand Autism Spectrum Disorder?

Autism Spectrum Disorder (ASD) is a frequent neurodevelopmental disorder. ASD is probably the result of intricate interactions between genes and environment altering progressively the development of brain structures and functions. Circadian rhythms are a complex intrinsic timing system composed of almost as many clocks as there are body cells. They regulate a variety of physiological and behavioral processes such as the sleep-wake rhythm. ASD is often associated with sleep disorders and low levels of melatonin. This first point raises the hypothesis that circadian rhythms could have an implication in ASD etiology. Moreover, circadian rhythms are generated by auto-regulatory genetic feedback loops, driven by transcription factors CLOCK and BMAL1, who drive transcription daily patterns of a wide number of clock-controlled genes (CCGs) in different cellular contexts across tissues. Among these, are some CCGs coding for synapses molecules associated to ASD susceptibility. Furthermore, evidence emerges about circadian rhythms control of time brain development processes.

Clinical value of R-spondins in triple-negative and metaplastic breast cancers

Background:

RSPO ligands, activators of the Wnt/β-catenin pathway, are overexpressed in different cancers. The objective of this study was to investigate the role of RSPOs in breast cancer (BC).

Methods:

Expression of RSPO and markers of various cancer pathways were measured in breast tumours and cell lines by qRT–PCR. The effect of RSPO on the Wnt/β-catenin pathway activity was determined by luciferase assay, western blotting, and qRT–PCR. The effect of RSPO2 inhibition on proliferation was determined by using RSPO2 siRNAs. The effect of IWR-1, an inhibitor of the Wnt/β-catenin pathway, was examined on the growth of an RSPO2-positive patient-derived xenograft (PDX) model of metaplastic triple-negative BC.

Results:

We detected RSPO2 and RSPO4 overexpression levels in BC, particularly in triple-negative BC (TNBC), metaplastic BC, and triple-negative cell lines. Various mechanisms could account for this overexpression: presence of fusion transcripts involving RSPO, and amplification or hypomethylation of RSPO genes. Patients with RSPO2-overexpressing tumours have a poorer metastasis-free survival (P=3.6 × 10⁻⁴). RSPO2 and RSPO4 stimulate Wnt/β-catenin pathway activity. Inhibition of RSPO expression in a TN cell line inhibits cell growth, and IWR-1 significantly inhibits the growth of an RSPO2-overexpressing PDX.

Conclusions:

RSPO overexpression could therefore be a new prognostic biomarker and therapeutic target for TNBC.

Demonstration of a memory for tightly guided light in an optical nanofiber

We report the experimental observation of slow-light and coherent storage in a setting where light is tightly confined in the transverse directions. By interfacing a tapered optical nanofiber with a cold atomic ensemble, electromagnetically induced transparency is observed and light pulses at the single-photon level are stored in and retrieved from the atomic medium. The decay of efficiency with storage time is also measured and related to concurrent decoherence mechanisms. Collapses and revivals can be additionally controlled by an applied magnetic field. Our results based on subdiffraction-limited optical mode interacting with atoms via the strong evanescent field demonstrate an alternative to free-space focusing and a novel capability for information storage in an all-fibered quantum network.

[Smith-Magenis syndrome is an association of behavioral and sleep/wake circadian rhythm disorders]

Smith-Magenis syndrome (SMS) is a genetic disorder characterized by the association of facial dysmorphism, oral speech delay, as well as behavioral and sleep/wake circadian rhythm disorders. Most SMS cases (90%) are due to a 17p11.2 deletion encompassing the RAI1 gene; other cases stem from mutations of the RAI1 gene. Behavioral issues may include frequent outbursts, attention deficit/hyperactivity disorders, self-injuries with onychotillomania and polyembolokoilamania (insertion of objects into bodily orifices), etc. It is noteworthy that the longer the speech delay and the more severe the sleep disorders, the more severe the behavioral issues are. Typical sleep/wake circadian rhythm disorders associate excessive daytime sleepiness with nocturnal agitation. They are related to an inversion of the physiological melatonin secretion cycle. Yet, with an adapted therapeutic strategy, circadian rhythm disorders can radically improve. Usually an association of beta-blockers in the morning (stops daily melatonin secretion) and melatonin in the evening (mimics the evening deficient peak) is used. Once the sleep disorders are controlled, effective treatment of the remaining psychiatric features is needed. Unfortunately, as for many orphan diseases, objective guidelines have not been drawn up. However, efforts should be focused on improving communication skills. In the same vein, attention deficit/hyperactivity disorders, aggressiveness, and anxiety should be identified and specifically treated. This whole appropriate medical management is underpinned by the diagnosis of SMS. Diagnostic strategies include fluorescent in situ hybridization (FISH) or array comparative genomic hybridization (array CGH) when a microdeletion is sought and Sanger sequencing when a point mutation is suspected. Thus, the diagnosis of SMS can be made from a simple blood sample and should be questioned in subjects of any age presenting with an association of facial dysmorphism, speech delay with behavioral and sleep/wake circadian rhythm disorders, and other anomalies including short stature and mild dysmorphic features.

Assessment of Exposure to Perchloroethylene and its Clinical Repercussions for 50 Dry-Cleaning Employees

The purpose of this article is the assessment of occupational exposure to perchloroethylene (PCE) and its clinical repercussions for dry-cleaning employees. The authors measured atmospheric levels of PCE and blood levels in a population of 50 exposed employees then conducted a study of clinical symptomatology in exposed and non-exposed subjects linked with this solvent. Fifty employees and 95 controls were studied. The median value of atmospheric PCE was 7 ppm (0.22-33), and the median blood level of PCE was 73.6 μg/l (11.8-144). These levels were correlated statistically to the action of sludge scraping and to the existence of automatic scrapers (p < 0.01). Eight percent of PCE blood levels were higher than the biological levels recently set in France. The exposed population did not show excessive signs of drowsiness nor of pre-narcotic syndrome or other symptoms studied. Dry-cleaning employees were exposed to PCE at atmospheric levels lower than the French and American chronic recommended exposure levels but some results were higher than recommended values. For PCE blood levels for the general working population, results were respectively lower than French and American national recommended levels in 92% and 94% cases. Risk should be considered, however, carefully in women of childbearing age, as 64% exceeded the recommended blood levels for pregnant women. This exposure did not generate any studied neurobehavioral symptomatology.

Determination of the purity of valine by isocratic liquid chromatography coupled with charged aerosol detection (CAD)

A liquid chromatography coupled with charged aerosol detection (LC-CAD) procedure; capable of separating and quantifying the most common impurities of valine at levels as low as 0.05 per cent (m/m), has been developed. The procedure is simple (isocratic), rapid, linear, sensitive and repeatable. It employs a widely available and inexpensive stationary phase (C18).

The FEN1 E359K germline mutation disrupts the FEN1-WRN interaction and FEN1 GEN activity, causing aneuploidy-associated cancers

Polymorphisms and somatic mutations in Flap Endonuclease 1 (FEN1), an essential enzyme involved in DNA replication and repair, can lead to functional deficiencies of the FEN1 protein and a predisposition to cancer. We identified a FEN1 germline mutation which changed residue E359 to K in a patient whose family had a history of breast cancer. We determined that the E359K mutation, which is in the protein-protein domain of FEN1, abolished the interaction of FEN1 with Werner Syndrome protein (WRN), an interaction which is critical for resolving stalled DNA replication forks. Furthermore, although the flap endonuclease activity of FEN1 E359K was unaffected, it failed to resolve bubble structures, which requires the FEN1 gap dependent endonuclease (GEN) activity. To determine the etiological significance of E359K, we established a mouse model containing this mutation. E359K mouse embryonic fibroblasts (MEF) were more sensitive to DNA cross-linking agents that cause replication forks to stall. Cytological analysis suggested that the FEN1-WRN interaction was also required to for telomere stability; mutant cell lines had fragile telomeres, increased numbers of spontaneous chromosomal anomalies and higher frequencies of transformation. Moreover, the incidence of cancer was significantly higher in mice homozygous for FEN1 E359K than in wild-type mice, suggesting that the FEN1 E359K mutation is oncogenic.

Reversible optical memory for twisted photons

We report on an experiment in which orbital angular momentum (OAM) of light is mapped at the single-photon level into and out of a cold atomic ensemble. Based on the dynamic electromagnetically induced transparency protocol, the demonstrated optical memory enables the reversible mapping of Laguerre-Gaussian modes with preserved handedness of the helical phase structure. The demonstrated capability opens the possibility to the storage of qubits encoded as superpositions of OAM states and to multidimensional light matter interfacing.

Detection of hazardous weight-loss substances in adulterated slimming formulations using ultra-high-pressure liquid chromatography with diode-array detection

The presence on the market of illegal products for slimming purposes or the treatment of overweight is a public health issue. These products may contain illicit chemicals in order to improve their effectiveness. Some of these weight-loss compounds are responsible for adverse events, including fatal outcomes. A general strategy for the analysis of any suspect formulation begins with a large screening for the general search of a wide range of compounds. A methodology for the qualitative and quantitative determination of 34 compounds in slimming preparations (such as dietary supplements or medicinal products) was used for the control of slimming formulations from the market, including over the Internet. The fast liquid chromatography system (ultra-high-pressure liquid chromatography) used a gradient of solvent (phosphate buffer and acetonitrile), a C18 endcapped column and a diode array detector. This system allows dual identification based on retention time and UV spectra. The analytical method is simple, fast and selective since 34 weight-loss compounds can be detected in a 15-min run time. Thus, 32 commercial slimming formulations were analysed using this method, allowing the detection and quantification of hazardous active substances: caffeine, clenbuterol, nicotinamide, phenolphthalein, rimonabant, sibutramine, didesmethylsibutramine, synephrine and yohimbine.

XUTs are a class of Xrn1-sensitive antisense regulatory non-coding RNA in yeast

Non-coding (nc)RNAs are key players in numerous biological processes such as gene regulation, chromatin domain formation and genome stability. Large ncRNAs interact with histone modifiers and are involved in cancer development, X-chromosome inactivation and autosomal gene imprinting. However, despite recent evidence showing that pervasive transcription is more widespread than previously thought, only a few examples mediating gene regulation in eukaryotes have been described. In Saccharomyces cerevisiae, the bona-fide regulatory ncRNAs are destabilized by the Xrn1 5'-3' RNA exonuclease (also known as Kem1), but the genome-wide characterization of the entire regulatory ncRNA family remains elusive. Here, using strand-specific RNA sequencing (RNA-seq), we identify a novel class of 1,658 Xrn1-sensitive unstable transcripts (XUTs) in which 66% are antisense to open reading frames. These transcripts are polyadenylated and RNA polymerase II (RNAPII)-dependent. The majority of XUTs strongly accumulate in lithium-containing media, indicating that they might have a role in adaptive responses to changes in growth conditions. Notably, RNAPII chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) analysis of Xrn1-deficient strains revealed a significant decrease of RNAPII occupancy over 273 genes with antisense XUTs. These genes show an unusual bias for H3K4me3 marks and require the Set1 histone H3 lysine 4 methyl-transferase for silencing. Furthermore, abolishing H3K4me3 triggers the silencing of other genes with antisense XUTs, supporting a model in which H3K4me3 antagonizes antisense ncRNA repressive activity. Our results demonstrate that antisense ncRNA-mediated regulation is a general regulatory pathway for gene expression in S. cerevisiae.