Novel modelling approaches to predict the role of antivirals in reducing influenza transmission.

To aid understanding of the effect of antiviral treatment on population-level influenza transmission, we used a novel pharmacokinetic-viral kinetic transmission model to test the correlation between nasal viral load and infectiousness, and to evaluate the impact that timing of treatment with the antivirals oseltamivir or baloxavir has on influenza transmission. The model was run under three candidate profiles whereby infectiousness was assumed to be proportional to viral titer on a natural-scale, log-scale, or dose-response model. Viral kinetic profiles in the presence and absence of antiviral treatment were compared for each individual (N = 1000 simulated individuals); subsequently, viral transmission mitigation was calculated. The predicted transmission mitigation was greater with earlier administration of antiviral treatment, and with baloxavir versus oseltamivir. When treatment was initiated 12-24 hours post symptom onset, the predicted transmission mitigation was 39.9-56.4% for baloxavir and 26.6-38.3% for oseltamivir depending on the infectiousness profile. When treatment was initiated 36-48 hours post symptom onset, the predicted transmission mitigation decreased to 0.8-28.3% for baloxavir and 0.8-19.9% for oseltamivir. Model estimates were compared with clinical data from the BLOCKSTONE post-exposure prophylaxis study, which indicated the log-scale model for infectiousness best fit the observed data and that baloxavir affords greater reductions in secondary case rates compared with neuraminidase inhibitors. These findings suggest a role for baloxavir and oseltamivir in reducing influenza transmission when treatment is initiated within 48 hours of symptom onset in the index patient.

Variations in the sonographic measurement techniques of BI-RADS 3 breast masses.

OBJECTIVE: To evaluate the differences in sonographic (US) distance and volume measurements from different sonologists and identify the optimal parameters to avoid clinically relevant variations in the measurement of BI-RADS 3 breast masses. METHODS: For this cross-sectional study with prospectively collected data, four physicians with various levels of experience in US, herein called sonologists, performed distance and volume US measurements of 80 masses classified as BI-RADS 3. The Cochran Q test was used to compare the matched sets of rates of clinically relevant variability between all pairs of sonologists' measurements. RESULTS: There were clinically relevant differences between sonologists in the measurements of the longest diameter (range, 17.5-43.7%, p = 0.003), the longest diameter perpendicular to the previous one (anteroposterior diameter) (17.5-33.7%, p = 0.06), the third diameter orthogonal to the plane defined by the previous two (transverse diameter) (28.7-55%, p = 0.001), and at least two of those three diameters (18.7-38.7%, p = 0.015). The smallest clinically relevant differences were observed with volume measurements (range of differences, 6.2-13.7%, p = 0.51). CONCLUSIONS: Volume measurement technique was associated with the least variations, whereas distance measurements, which are used routinely, were associated with unacceptable rates of clinically relevant variations. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:252-260, 2017.

Experimental evidence for a Bragg glass density wave phase in a transition-metal dichalcogenide.

Analysis of the spatial dependence of current-voltage characteristics obtained from scanning tunneling microscopy experiments indicates that the charge density wave (CDW) occurring in NbSe_{2} is subject to locally strong pinning by a non-negligible density of defects, but that on the length scales accessible in this experiment the material is in a "Bragg glass" phase where dislocations and antidislocations occur in bound pairs and free dislocations are not observed. An analysis based on a Landau theory is presented showing how a strong local modulation may produce only a weak long range effect on the CDW phase.

Ferromagnetic ordering in superatomic solids.

In order to realize significant benefits from the assembly of solid-state materials from molecular cluster superatomic building blocks, several criteria must be met. Reproducible syntheses must reliably produce macroscopic amounts of pure material; the cluster-assembled solids must show properties that are more than simply averages of those of the constituent subunits; and rational changes to the chemical structures of the subunits must result in predictable changes in the collective properties of the solid. In this report we show that we can meet these requirements. Using a combination of magnetometry and muon spin relaxation measurements, we demonstrate that crystallographically defined superatomic solids assembled from molecular nickel telluride clusters and fullerenes undergo a ferromagnetic phase transition at low temperatures. Moreover, we show that when we modify the constituent superatoms, the cooperative magnetic properties change in predictable ways.

Characteristics and outcomes of multisystem inflammatory syndrome in children: A multicenter, retrospective, observational cohort study in Mexico.

Introduction: Multisystem inflammatory syndrome in children associated with coronavirus disease 2019 (MIS-C), a novel hyperinflammatory condition secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is associated with severe outcomes such as coronary artery aneurysm and death. Methods: This multicenter, retrospective, observational cohort study including eight centers in Mexico, aimed to describe the clinical characteristics and outcomes of patients with MIS-C. Patient data were evaluated using latent class analysis (LCA) to categorize patients into three phenotypes: toxic shock syndrome-like (TSSL)-MIS-C, Kawasaki disease-like (KDL)-MIS-C, and nonspecific MIS-C (NS-MIS-C). Risk factors for adverse outcomes were estimated using multilevel mixed-effects logistic regression. Results: The study included 239 patients with MIS-C, including 61 (26%), 70 (29%), and 108 (45%) patients in the TSSL-MIS-C, KDL-MIS-C, and NS-MIS-C groups, respectively. Fifty-four percent of the patients were admitted to the intensive care unit, and 42%, 78%, and 41% received intravenous immunoglobulin, systemic glucocorticoids, and anticoagulants, respectively. Coronary artery dilatation and aneurysms were found in 5.7% and 13.2% of the patients in whom coronary artery diameter was measured, respectively. Any cause in-hospital mortality was 5.4%. Hospitalization after ten days of symptoms was associated with coronary artery abnormalities (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.0). Age ≥10 years (OR: 5.6, 95% CI: 1.4-2.04), severe underlying condition (OR: 9.3, 95% CI: 2.8-31.0), platelet count <150,000 /mm3 (OR: 4.2, 95% CI: 1.2-14.7), international normalized ratio >1.2 (OR: 3.8, 95% CI: 1.05-13.9), and serum ferritin concentration >1,500 mg/dl at admission (OR: 52, 95% CI: 5.9-463) were risk factors for death. Discussion: Mortality in patients with MIS-C was higher than reported in other series, probably because of a high rate of cases with serious underlying diseases.

Exploring Early Pre-Symptomatic Detection of Influenza Using Continuous Monitoring of Advanced Physiological Parameters during a Randomized Controlled Trial.

Early detection of influenza may improve responses against outbreaks. This study was part of a clinical study assessing the efficacy of a novel influenza vaccine, aiming to discover distinct, highly predictive patterns of pre-symptomatic illness based on changes in advanced physiological parameters using a novel wearable sensor. Participants were frequently monitored 24 h before and for nine days after the influenza challenge. Viral load was measured daily, and self-reported symptoms were collected twice a day. The Random Forest classifier model was used to classify the participants based on changes in the measured parameters. A total of 116 participants with ~3,400,000 data points were included. Changes in parameters were detected at an early stage of the disease, before the development of symptomatic illness. Heart rate, blood pressure, cardiac output, and systemic vascular resistance showed the greatest changes in the third post-exposure day, correlating with viral load. Applying the classifier model identified participants as flu-positive or negative with an accuracy of 0.81 ± 0.05 two days before major symptoms appeared. Cardiac index and diastolic blood pressure were the leading predicting factors when using data from the first and second day. This study suggests that frequent remote monitoring of advanced physiological parameters may provide early pre-symptomatic detection of flu.

RCE1 corneal epithelial cell line: its variability on phenotype expression and differential response to growth factors.

BACKGROUND: By serial transfer of rabbit corneal epithelial cells, the spontaneous RCE1 cell line was previously established. These cells mimic the stage-dependent differentiation of the corresponding cell type. METHODS: RCE1 cells were cultured either on plastic culture dishes or on collagen rafts to compare the epithelial ultrastructure after growth on these substrata. Phenotypic variability was studied after subcloning of cells. The differentiation ability of each subclone was determined by Western blot with antibodies against the differentiation-linked keratin pair K3/K12 and by measuring LDH activity and LDH isozymes in cytosolic extracts. The proliferative response of RCE1 cells to EGF, TGFalpha, amphiregulin, bFGF or IL-6 was determined under serum-free culture conditions. RESULTS: Cells grown on collagen rafts formed 5- to 7-layered epithelia with characteristics closer to those found in normal corneal epithelium than cells cultivated on plastic substrata, which formed 3- to 5-layered epithelia. Subcloning experiments demonstrated that every proliferative cell is able to grow and constitute stratified epithelia expressing K3/K12 keratins. LDH levels in RCE1 epithelia were similar to those of cultured or freshly harvested corneal epithelia; however, they showed a slightly altered LDH isozyme set, with prevalence of LDH-3 isoform. Whereas EGF and TGF-alpha were equipotent, amphiregulin elicited a 4-fold lower proliferative response. Also, bFGF was 10-fold less mitogenic than EGF, and IL-6 had the lowest effect with an ED(50) 20-fold lower than EGF. CONCLUSIONS: The results demonstrate that every RCE1 proliferative cell has the ability to generate epithelial sheets. We conclude that EGF and TGF-alpha are the major effectors of RCE1 cell proliferation.

Visualizing individual nitrogen dopants in monolayer graphene.

In monolayer graphene, substitutional doping during growth can be used to alter its electronic properties. We used scanning tunneling microscopy, Raman spectroscopy, x-ray spectroscopy, and first principles calculations to characterize individual nitrogen dopants in monolayer graphene grown on a copper substrate. Individual nitrogen atoms were incorporated as graphitic dopants, and a fraction of the extra electron on each nitrogen atom was delocalized into the graphene lattice. The electronic structure of nitrogen-doped graphene was strongly modified only within a few lattice spacings of the site of the nitrogen dopant. These findings show that chemical doping is a promising route to achieving high-quality graphene films with a large carrier concentration.

What is a chromosome like in Leishmania?

Hereby, we present evidences of the presence of centromeric proteins in Leishmania mexicana. These proteins were partially purified and used to bind Leishmania DNA. The protein-DNA complex was immunoprecipitated and the DNA extracted, like in the human sample. Two major fragments of 1.2 and 2.2 Kbp, respectively, were resolved in agarose gel electrophoresis. A model of chromosomal structure and chromosomal segregation in Leishmania is presented

Variability in the cell phenotype of aggregates or "clones" of human osteoarthritic cartilage. A case report

Human samples of articular cartilage from the knee of a clinically classified osteoarthritic patient, assessed by arthroscopy as part of the surgical treatment was studied by light and transmission electron microscopy. This particular case differed from others already reported in the variability of cell phenotype within the aggregates or "clones" frequently present in the osteoarthritic cartilage. The most common morphology of "clonal" cells forming the aggregates were large and rounded with an euchromatic nucleus. The cytoplasm was characterized by the presence of alternately clear and dense sites. At the ultrastructural level it was seen that the clear sites were formed by disrupted intermediates filaments and small particles, and that the dense sites were constituted by the segregation of different organelles of the chondrocytes. In addition, there were atypical aggregates composed only by secretory cells or by degenerating chondrocytes. Furthermore, a complex structure consisting of a very large cell inside a giant lacunae delimited by electron-dense material with small vesicles is described as a novel finding. The variability in the chondrocyte phenotype of the aggregates described here could be an indication of a better prognosis; nevertheless, the follow-up of the evolution of this patient is needed in order to know the final outcome.