Quantitative weight of evidence method for combining predictions of quantitative structure-activity relationship models

A method for combining statistical-based QSAR predictions of two or more binary classification models is presented. It was assumed that all models were independent. This facilitated the combination of positive and negative predictions using a quantitative weight of evidence (qWoE) procedure based on Bayesian statistics and the additivity of the logarithms of the likelihood ratios. Previous studies combined more than one prediction but used arbitrary strengths for positive and negative predictions. In our approach, the combined models were validated by determining the sensitivity and specificity values, which are performance metrics that are a point of departure for obtaining values that measure the weight of evidence of positive and negative predictions. The developed method was experimentally applied in the prediction of Ames mutagenicity. The method achieved a similar accuracy to that of the experimental Ames test for this endpoint when the overall prediction was determined using a combination of the individual predictions of more than one model. Calculating the qWoE value would reduce the requirement for expert knowledge and decrease the subjectivity of the prediction. This method could be applied to other endpoints such as developmental toxicity and skin sensitisation with binary classification models.

Extensive dissemination and intraclonal maturation of HIV Env vaccine-induced B cell responses

Well-ordered HIV-1 envelope glycoprotein (Env) trimers are prioritized for clinical evaluation, and there is a need for an improved understanding about how elicited B cell responses evolve following immunization. To accomplish this, we prime-boosted rhesus macaques with clade C NFL trimers and identified 180 unique Ab lineages from ∼1,000 single-sorted Env-specific memory B cells. We traced all lineages in high-throughput heavy chain (HC) repertoire (Rep-seq) data generated from multiple immune compartments and time points and expressed several as monoclonal Abs (mAbs). Our results revealed broad dissemination and high levels of somatic hypermutation (SHM) of most lineages, including tier 2 virus neutralizing lineages, following boosting. SHM was highest in the Ab complementarity determining regions (CDRs) but also surprisingly high in the framework regions (FRs), especially FR3. Our results demonstrate the capacity of the immune system to affinity-mature large numbers of Env-specific B cell lineages simultaneously, supporting the use of regimens consisting of repeated boosts to improve each Ab, even those belonging to less expanded lineages.

Sarek: A portable workflow for whole-genome sequencing analysis of germline and somatic variants

Whole-genome sequencing (WGS) is a fundamental technology for research to advance precision medicine, but the limited availability of portable and user-friendly workflows for WGS analyses poses a major challenge for many research groups and hampers scientific progress. Here we present Sarek, an open-source workflow to detect germline variants and somatic mutations based on sequencing data from WGS, whole-exome sequencing (WES), or gene panels. Sarek features (i) easy installation, (ii) robust portability across different computer environments, (iii) comprehensive documentation, (iv) transparent and easy-to-read code, and (v) extensive quality metrics reporting. Sarek is implemented in the Nextflow workflow language and supports both Docker and Singularity containers as well as Conda environments, making it ideal for easy deployment on any POSIX-compatible computers and cloud compute environments. Sarek follows the GATK best-practice recommendations for read alignment and pre-processing, and includes a wide range of software for the identification and annotation of germline and somatic single-nucleotide variants, insertion and deletion variants, structural variants, tumour sample purity, and variations in ploidy and copy number. Sarek offers easy, efficient, and reproducible WGS analyses, and can readily be used both as a production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups. The Sarek source code, documentation and installation instructions are freely available at https://github.com/nf-core/sarek and at https://nf-co.re/sarek/.

Sarek: A portable workflow for whole-genome sequencing analysis of germline and somatic variants

Whole-genome sequencing (WGS) is a fundamental technology for research to advance precision medicine, but the limited availability of portable and user-friendly workflows for WGS analyses poses a major challenge for many research groups and hampers scientific progress. Here we present Sarek, an open-source workflow to detect germline variants and somatic mutations based on sequencing data from WGS, whole-exome sequencing (WES), or gene panels. Sarek features (i) easy installation, (ii) robust portability across different computer environments, (iii) comprehensive documentation, (iv) transparent and easy-to-read code, and (v) extensive quality metrics reporting. Sarek is implemented in the Nextflow workflow language and supports both Docker and Singularity containers as well as Conda environments, making it ideal for easy deployment on any POSIX-compatible computers and cloud compute environments. Sarek follows the GATK best-practice recommendations for read alignment and pre-processing, and includes a wide range of software for the identification and annotation of germline and somatic single-nucleotide variants, insertion and deletion variants, structural variants, tumour sample purity, and variations in ploidy and copy number. Sarek offers easy, efficient, and reproducible WGS analyses, and can readily be used both as a production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups. The Sarek source code, documentation and installation instructions are freely available at https://github.com/nf-core/sarek and at https://nf-co.re/sarek/.

Nationwide survey on training and device utilization during tracheal intubation in French intensive care units

Background

Intubation is a lifesaving procedure that is often performed in intensive care unit (ICU) patients, but leads to serious adverse events in 20–40% of cases. Recent trials aimed to provide guidance about which medications, devices, and modalities maximize patient safety. Videolaryngoscopes are being offered in an increasing range of options and used in broadening indications (from difficult to unremarkable intubation). The objective of this study was to describe intubation practices and device availability in French ICUs.

Materials and methods

We conducted an online nationwide survey by emailing an anonymous 26-item questionnaire to physicians in French ICUs. A single questionnaire was sent to either the head or the intubation expert at each ICU.

Results

Of 257 ICUs, 180 (70%) returned the completed questionnaire. The results showed that 43% of intubators were not fully proficient in intubation; among them, 18.8% had no intubation training or had received only basic training (lectures and observation at the bedside). Among the participating ICUs, 94.4% had a difficult intubation trolley, 74.5% an intubation protocol, 92.2% a capnography device (used routinely to check tube position in 69.3% of ICUs having the device), 91.6% a laryngeal mask, 97.2% front-of-neck access capabilities, and 76.6% a videolaryngoscope. In case of difficult intubation, 85.6% of ICUs used a bougie (154/180) and 7.8% switched to a videolaryngoscope (14/180). Use of a videolaryngoscope was reserved for difficult intubation in 84% of ICUs (154/180). Having a videolaryngoscope was significantly associated with having an intubation protocol (P = 0.043) and using capnography (P = 0.02). Airtraq^® was the most often used videolaryngoscope (39.3%), followed by McGrath^®Mac (36.9%) then by Glidescope^® (14.5%).

Conclusion

Nearly half the intubators in French ICUs are not fully proficient with OTI. Access to modern training methods such as simulation is inadequate. Most ICUs own a videolaryngoscope, but reserve it for difficult intubations.

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry

BACKGROUND

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy.

METHODS

We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel).

RESULTS

In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n = 171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n = 382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors.

CONCLUSIONS

Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences.

Can environmental contamination be explained by particular traits associated with patients?

BACKGROUND

Little is known about patient risk factors associated with environmental contamination.

AIM

To evaluate the rate of environmental contamination and to investigate individual risk factors.

METHODS

A prospective cohort study was conducted. Each day, five rooms occupied by patients were selected. Five critical surfaces were systematically swabbed twice a day before and after cleaning. Clinical characteristics of all patients were collected. Logisitic regression was performed to evaluate the association between environmental contamination and patients' characteristics.

FINDINGS

A total of 107 consecutive patients were included and 1052 environmental samples were performed. Nineteen (18%) patients were known previously colonized/infected with a multidrug-resistant organism (MDRO). Respectively, 723 (69%) and 112 (11%) samples grew with ≥1 and >2.5 cfu/cm² bacteria, resulting in 62 (58%) contaminated rooms. Considering positive samples with at least one pathogenic bacterium, 16 (15%) rooms were contaminated. By univariate and multivariate analysis, no variables analysed were associated with the environmental contamination. Considering contaminated rooms with >2.5 cfu/cm², three factors were protective for environmental contamination: known MDRO carriers/infected patients (odds ratio: 0.25; 95% confidence interval: 0.09-0.72; P = 0.01), patients with urinary catheter (0.19; 0.04-0.89; P = 0.03) and hospitalization in single room (0.3; 0.15-0.6; P < 0.001).

CONCLUSION

This study was conducted in a non-outbreak situation and showed a low rate of environmental contamination with pathogenic bacteria. Only 11% of environmental samples grew with >2.5 cfu/cm², and they were related to non-pathogenic bacteria. No risk factors associated with environmental contamination were identified.

Bulk and grain boundary Li-diffusion in dense LiMn2O4 pellets by means of isotope exchange and ToF-SIMS analysis

Lithium diffusion in LiMn₂O₄ pellets is studied by means of isotope exchange and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). A ⁶Li-enriched film deposited by Pulsed Laser Deposition (PLD) on a dense LiMn₂O₄ pellet with natural abundance of lithium isotopes is used to study the tracer diffusion of lithium. The measured profiles are analyzed by numerical models describing the ⁶Li tracer diffusion from the film into the pellet. Experiments in the Harrison type B regime of diffusion kinetics allow for the distinction and simultaneous determination of bulk and grain boundary diffusion coefficients. Changing the experimental conditions to reach Harrison type A behavior yields effective diffusion coefficients for lithium tracer diffusion in LiMn₂O₄. Activation energies for bulk and grain boundary diffusion were obtained from experiments at different temperatures. Our values are critically compared to previous studies.

Impact of palbociclib plus letrozole on patient-reported health-related quality of life: results from the PALOMA-2 trial

Background

Patient-reported outcomes are integral in benefit-risk assessments of new treatment regimens. The PALOMA-2 study provides the largest body of evidence for patient-reported health-related quality of life (QOL) for patients with metastatic breast cancer (MBC) receiving first-line endocrine-based therapy (palbociclib plus letrozole and letrozole alone).

Patients and methods

Treatment-naïve postmenopausal women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) MBC were randomized 2 : 1 to palbociclib plus letrozole (n = 444) or placebo plus letrozole (n = 222). Patient-reported outcomes were assessed at baseline, day 1 of cycles 2 and 3, and day 1 of every other cycle from cycle 5 using the Functional Assessment of Cancer Therapy (FACT)-Breast and EuroQOL 5 dimensions (EQ-5D) questionnaires.

Results

As of 26 February 2016, the median duration of follow-up was 23 months. Baseline scores were comparable between the two treatment arms. No significant between-arm differences were observed in change from baseline in FACT-Breast Total, FACT-General Total, or EQ-5D scores. Significantly greater improvement in pain scores was observed in the palbociclib plus letrozole arm (-0.256 versus -0.098; P = 0.0183). In both arms, deterioration of FACT-Breast Total score was significantly delayed in patients without progression versus those with progression and patients with partial or complete response versus those without. No significant difference was observed in FACT-Breast and EQ-5D index scores in patients with and without neutropenia.

Conclusions

Overall, women with MBC receiving first-line endocrine therapy have a good QOL. The addition of palbociclib to letrozole maintains health-related QOL and improves pain scores in treatment-naïve postmenopausal patients with ER+/HER2- MBC compared with letrozole alone. Significantly greater delay in deterioration of health-related QOL was observed in patients without progression versus those who progressed and in patients with an objective response versus non-responders. ClinicalTrials.gov: NCT01740427 (https://clinicaltrials.gov/ct2/show/NCT01740427).

[Inflammatory myopathy following acute meningoccemia in a properdin-deficient patient: A case report]

INTRODUCTION

Myalgia is a classical sign in invasive meningococcal diseases (IMD), but severe and persistent myalgia following an IMD have never been reported to date.

CASE REPORT

A 20-year-old man presented with purpura fulminans and meningitis caused by Neisseria meningitidis serogroup Y, revealing properdin deficiency. Although meningitis symptoms improved after antibiotherapy, initial myalgia of the lower limbs increased, associated with mild rhabdomyolysis. Magnetic resonance imaging (MRI) revealed an increased STIR (Short TI inversion recovery) signal of both quadriceps muscles, without abscess. After exclusion of other causes of myopathy, a post-infectious myositis was diagnosed. A four-week course of corticosteroids led to dramatic improvement.

CONCLUSION

Post-infectious inflammatory myopathy should be suspected in case of severe and persistent myalgia associated with rhabdomyolysis following an IMD, after exclusion of pyomyositis especially. A short course of corticosteroids seems to be effective.

Situation, challenges, and SEOM recommendations for the future of undergraduate education in Oncology in Spain

PURPOSE

The Spanish Society of Medical Oncology (SEOM, for its Spanish acronym) would like to attest to the relevance of training in Oncology as part of the undergraduate education in Medicine program and issue recommendations to improve said training, with the aim of responding better to the challenges that cancer poses to our society.

MATERIALS AND METHODS

The curricula of 42 schools of medicine were reviewed with interviews with at least one teaching medical oncologist from each faculty. The qualitative and opinion analysis was completed by means of an online questionnaire targeting lecturers, resident tutors, and residents in Medical Oncology (MO), enabling the detection of needs and areas for improvement at an organizational level and in terms of skill acquisition.

RESULTS

While the number of medical schools with a specific, mandatory program in MO has grown by up to 90%, it has not been accompanied by an increase in independent programs. Instead, they largely consist of programs shared with other specialties (61% of the medical faculties). In most of the undergraduate education programs, Oncology contents are fragmented and approached from the perspective of each organ system.

CONCLUSIONS

Despite the positive evolution in recent years, the heterogeneity in Oncology contents during undergraduate education training continues to be remarkable. Cross-sectional programs with an integral vision, taught in the final years of undergraduate medical education would be desirable. Among the recommendations for improvement of training in Medical Oncology, the SEOM proposes that updated, theoretical content be incorporated and clinical practice in Medical Oncology departments be promoted.

From cytogenetics to cytogenomics: whole-genome sequencing as a first-line test comprehensively captures the diverse spectrum of disease-causing genetic variation underlying intellectual disability

Background

Since different types of genetic variants, from single nucleotide variants (SNVs) to large chromosomal rearrangements, underlie intellectual disability, we evaluated the use of whole-genome sequencing (WGS) rather than chromosomal microarray analysis (CMA) as a first-line genetic diagnostic test.

Methods

We analyzed three cohorts with short-read WGS: (i) a retrospective cohort with validated copy number variants (CNVs) (cohort 1, n = 68), (ii) individuals referred for monogenic multi-gene panels (cohort 2, n = 156), and (iii) 100 prospective, consecutive cases referred to our center for CMA (cohort 3). Bioinformatic tools developed include FindSV, SVDB, Rhocall, Rhoviz, and vcf2cytosure.

Results

First, we validated our structural variant (SV)-calling pipeline on cohort 1, consisting of three trisomies and 79 deletions and duplications with a median size of 850 kb (min 500 bp, max 155 Mb). All variants were detected. Second, we utilized the same pipeline in cohort 2 and analyzed with monogenic WGS panels, increasing the diagnostic yield to 8%. Next, cohort 3 was analyzed by both CMA and WGS. The WGS data was processed for large (> 10 kb) SVs genome-wide and for exonic SVs and SNVs in a panel of 887 genes linked to intellectual disability as well as genes matched to patient-specific Human Phenotype Ontology (HPO) phenotypes. This yielded a total of 25 pathogenic variants (SNVs or SVs), of which 12 were detected by CMA as well. We also applied short tandem repeat (STR) expansion detection and discovered one pathologic expansion in ATXN7. Finally, a case of Prader-Willi syndrome with uniparental disomy (UPD) was validated in the WGS data.

Important positional information was obtained in all cohorts. Remarkably, 7% of the analyzed cases harbored complex structural variants, as exemplified by a ring chromosome and two duplications found to be an insertional translocation and part of a cryptic unbalanced translocation, respectively.

Conclusion

The overall diagnostic rate of 27% was more than doubled compared to clinical microarray (12%). Using WGS, we detected a wide range of SVs with high accuracy. Since the WGS data also allowed for analysis of SNVs, UPD, and STRs, it represents a powerful comprehensive genetic test in a clinical diagnostic laboratory setting.

Randomised phase III trial of vinflunine plus capecitabine versus capecitabine alone in patients with advanced breast cancer previously treated with an anthracycline and resistant to taxane

Background

Capecitabine is an approved standard therapy for anthracycline- and taxane-pretreated locally advanced or metastatic breast cancer (BC). Vinflunine has demonstrated single-agent activity in phase II studies in this setting and activity and tolerability when combined with capecitabine. We compared the combination of vinflunine plus capecitabine (VC) with single-agent capecitabine.

Patients and methods

Patients with locally recurrent/metastatic BC previously treated or resistant to an anthracycline and resistant to taxane therapy were randomly assigned to either vinflunine (280 mg/m2, day 1) plus oral capecitabine [825 mg/m2 twice daily (b.i.d.), days 1-14] every 3 weeks (q3w) or single-agent oral capecitabine (1250 mg/m2 b.i.d., days 1-14) q3w. The primary end point was progression-free survival (PFS) assessed by an independent review committee. The study had 90% power to detect a 30% improvement in PFS.

Results

Overall, 770 patients were randomised. PFS was significantly longer with VC than with capecitabine alone [hazard ratio, 0.84, 95% confidence interval (CI), 0.71-0.99; log-rank P = 0.043; median 5.6 versus 4.3 months, respectively]. Median overall survival was 13.9 versus 11.7 months with VC versus capecitabine alone, respectively (hazard ratio, 0.98; 95% CI, 0.83-1.15; log-rank P = 0.77). No difference in quality of life was observed between the two treatment arms. The most common adverse events (NCI CTCAE version 3.0) in the combination arm were haematological and gastrointestinal. Grade 4 neutropenia was more frequent with VC (12% versus 1% with capecitabine alone); febrile neutropenia occurred in 2% versus 0.5%, respectively. Hand-foot syndrome was less frequent with VC (grade 3: 4% versus 19% for capecitabine alone). Peripheral neuropathy was uncommon in both arms (grade 3: 1% versus 0.3%).

Conclusions

Vinflunine combined with capecitabine demonstrated a modest improvement in PFS and an acceptable safety profile compared with capecitabine alone in patients with anthracycline- and taxane-pretreated locally recurrent/metastatic BC.

ClinicalTrials.gov

NCT01095003.