Circadian dysfunction induces NAFLD-related human liver cancer in a mouse model.

BACKGROUND & AIMS: Chronic circadian dysfunction increases the risk of non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC), but the underlying mechanisms and direct relevance to human HCC have not been established. In this study, we aimed to determine whether chronic circadian dysregulation can drive NAFLD-related carcinogenesis from human hepatocytes and human HCC progression. METHODS: Chronic jet lag of mice with humanized livers induces spontaneous NAFLD-related HCCs from human hepatocytes. The clinical relevance of this model was analysed by biomarker, pathological/histological, genetic, RNA sequencing, metabolomic, and integrated bioinformatic analyses. RESULTS: Circadian dysfunction induces glucose intolerance, NAFLD-associated human HCCs, and human HCC metastasis independent of diet in a humanized mouse model. The deregulated transcriptomes in necrotic-inflammatory humanized livers and HCCs bear a striking resemblance to those of human non-alcoholic steatohepatitis (NASH), cirrhosis, and HCC. Stable circadian entrainment of hosts rhythmically paces NASH and HCC transcriptomes to decrease HCC incidence and prevent HCC metastasis. Circadian disruption directly reprogrammes NASH and HCC transcriptomes to drive a rapid progression from hepatocarcinogenesis to HCC metastasis. Human hepatocyte and tumour transcripts are clearly distinguishable from mouse transcripts in non-parenchymal cells and tumour stroma, and display dynamic changes in metabolism, inflammation, angiogenesis, and oncogenic signalling in NASH, progressing to hepatocyte malignant transformation and immunosuppressive tumour stroma in HCCs. Metabolomic analysis defines specific bile acids as prognostic biomarkers that change dynamically during hepatocarcinogenesis and in response to circadian disruption at all disease stages. CONCLUSION: Chronic circadian dysfunction is independently carcinogenic to human hepatocytes. Mice with humanized livers provide a powerful preclinical model for studying the impact of the necrotic-inflammatory liver environment and neuroendocrine circadian dysfunction on hepatocarcinogenesis and anti-HCC therapy. IMPACT AND IMPLICATIONS: Human epidemiological studies have linked chronic circadian dysfunction to increased hepatocellular carcinoma (HCC) risk, but direct evidence that circadian dysfunction is a human carcinogen has not been established. Here we show that circadian dysfunction induces non-alcoholic steatohepatitis (NASH)-related carcinogenesis from human hepatocytes in a murine humanized liver model, following the same molecular and pathologic pathways observed in human patients. The gene expression signatures of humanized HCC transcriptomes from circadian-disrupted mice closely match those of human HCC with the poorest prognostic outcomes, while those from stably circadian entrained mice match those from human HCC with the best prognostic outcomes. Our studies establish a new model for defining the mechanism of NASH-related HCC and highlight the importance of circadian biology in HCC prevention and treatment.

El ciberacoso entre jóvenes del barrio López de Mesa, Medellín-Colombia / Cyberbullying between young people in López de Mesa neighborhood of Medellín-Colombia

El ciberacoso es aquel fenómeno que se produce a través de dispositivos digitales como teléfonos celulares o computadoras; suele ocurrir generalmente mediante mensajes de texto o redes sociales. Este artículo tiene como objetivo analizar los efectos del ciberacoso en los jóvenes del barrio López de Mesa (Medellín-Colombia), así como también las causas, consecuencias y posibles métodos de intervención. Como instrumento de recolección de datos se ha utilizado la encuesta, a través de la cual se concluye que los jóvenes son quienes se ven más afectados por el fenómeno estudiado.

Cyberbullying is one that occurs through digital devices such as cell phones or computers. This is usually done by text messaging or social networking. The project aims to analyze the effects of cyberbullying on young people in the Lopez de Mesa neighborhood, as well as the causes, consequences and possible methods of intervention. On the other hand, the survey has been used as a data collection tool, which concludes that young people are the ones most affected by the studied phenomenon.

Boron-Implanted Silicon Substrates for Physical Adsorption of DNA Origami.

DNA nanostructures routinely self-assemble with sub-10 nm feature sizes. This capability has created industry interest in using DNA as a lithographic mask, yet with few exceptions, solution-based deposition of DNA nanostructures has remained primarily academic to date. En route to controlled adsorption of DNA patterns onto manufactured substrates, deposition and placement of DNA origami has been demonstrated on chemically functionalized silicon substrates. While compelling, chemical functionalization adds fabrication complexity that limits mask efficiency and hence industry adoption. As an alternative, we developed an ion implantation process that tailors the surface potential of silicon substrates to facilitate adsorption of DNA nanostructures without the need for chemical functionalization. Industry standard 300 mm silicon wafers were processed, and we showed controlled adsorption of DNA origami onto boron-implanted silicon patterns; selective to a surrounding silicon oxide matrix. The hydrophilic substrate achieves very high surface selectivity by exploiting pH-dependent protonation of silanol-groups on silicon dioxide (SiO2), across a range of solution pH values and magnesium chloride (MgCl2) buffer concentrations.

Neurophysiology of hearing in patients with mucopolysaccharidosis type IV.

BACKGROUND: Hearing impairment is a common problem in patients with mucopolysaccharidosis IV (MPS IV) throughout their life. Many of the adult patients with MPS IV exhibit permanent or severe hearing loss. However, there has been no systematic review of detailed audiological test results in MPS IV. MATERIALS AND METHODS: Fourteen individuals with MPS IV (13 MPS IVA and 1 MPS IVB; aged between 12 and 38 years old) participated in the current study. We obtained auditory neurophysiological responses (auditory brainstem responses and otoacoustic emissions test) in addition to pure-tone audiometry and middle ear function tests (tympanometry and acoustic reflexes). RESULTS: The results indicated various levels and types of hearing loss with abnormal neurophysiological responses even in those patients with MPS IVA with normal pure tone thresholds. We also found a strong relationship between height (short stature is an indicator of skeletal severity) and hearing sensitivity as well as a strong relationship between height and outer hair cell function in the inner ear (measured by otoacoustic emissions) among MPS IVA patients. CONCLUSION: The strong correlation between reduced height and hearing loss indicates that patients with severe skeletal dysplasia may be at higher risk of developing more severe hearing loss. More importantly, the spectrum of hearing disorders indicates that MPS IV patients should have annual neurophysiological hearing tests in addition to audiometric testing from an early age regardless of their skeletal severity to more carefully monitor disease progression.

Acute Confusional Migraine: Distinct Clinical Entity or Spectrum of Migraine Biology?

The goal of this review is to explore the literature reports of acute confusional migraine (ACM) including patient characteristics, migraine symptomatology, and proposed diagnostic criteria. A literature review was conducted using PubMed, Scopus and Web of Science using the terms "confusional migraine" and "confusional state in migraine". All the relevant articles from 1970 to 2016 were included. A total of 120 patients were found in the literature. Most of the cases were seen in the pediatric population with a slight male predominance. Personal or family history of migraine was common. Most patients had a headache prior to the confusional state. In addition to confusion and agitation, some developed visual (32.5%) and/or sensory symptoms (19%) and/or speech problems (39%) either prior to or during the confusional state. Data on treatment outcomes is lacking. Patients with most common forms of migraine report attention and cognitive disturbances but awareness remains intact as opposed to patients with ACM. ACM is a distinct entity and should be included as part of the appendix of International Classification of Headache Disoders-3 beta version (ICHD-3ß) criteria. Prospective studies are needed to further study this disorder and its association with other migraine forms.

Availability: A Metric for Nucleic Acid Strand Displacement Systems.

DNA strand displacement systems have transformative potential in synthetic biology. While powerful examples have been reported in DNA nanotechnology, such systems are plagued by leakage, which limits network stability, sensitivity, and scalability. An approach to mitigate leakage in DNA nanotechnology, which is applicable to synthetic biology, is to introduce mismatches to complementary fuel sequences at key locations. However, this method overlooks nuances in the secondary structure of the fuel and substrate that impact the leakage reaction kinetics in strand displacement systems. In an effort to quantify the impact of secondary structure on leakage, we introduce the concepts of availability and mutual availability and demonstrate their utility for network analysis. Our approach exposes vulnerable locations on the substrate and quantifies the secondary structure of fuel strands. Using these concepts, a 4-fold reduction in leakage has been achieved. The result is a rational design process that efficiently suppresses leakage and provides new insight into dynamic nucleic acid networks.

Prevalence of Auditory Processing Disorder in School-Aged Children in the Mid-Atlantic Region.

BACKGROUND: Although auditory processing disorder (APD) is a widely recognized impairment, its prevalence and demographic characteristics are not precisely known in the pediatric population. PURPOSE: To examine the demographic characteristics of children diagnosed with APD at a tertiary health-care facility and the prevalence of pediatric APD. RESEARCH DESIGN: A cross-sectional study. STUDY SAMPLE: A total of 243 children (149 boys and 94 girls) who were referred to the Nemours Audiology Clinics in the Delaware Valley for an APD evaluation. The mean ages were 9.8 yr for boys and 9.7 yr for girls. Out of 243 children referred for an APD evaluation, 94 children exhibited one or more auditory processing deficits in the areas of auditory closure, auditory figure ground, binaural integration, binaural separation, and temporal processing. DATA COLLECTION AND ANALYSIS: Demographic and audiological data, clinical history (parental reports on prenatal and postnatal information, birth weight and height, medical and developmental history, otologic/audiological history, education information, behavioral characteristics), and results of the APD test battery were retrospectively obtained from the electronic medical records of each participant. The prevalence of APD was estimated using the total number of students enrolled in the same school attended by each participant in the 2011 academic year as cohort. RESULTS: The prevalence of APD was 1.94 per 1,000 children in this study. We found that prevalence of APD among the children who attended private schools was more than two times higher than the children who attended public schools. The results also revealed that the majority of children referred to the clinics were Caucasian (85.6%), whereas minority groups were underrepresented for this geographical area with only 3.7% of Hispanic or Latino children and 5.8% of Black or African American children. CONCLUSIONS: The estimated prevalence of APD in the current study was lower than the previously published estimates. The difference might be due to the diagnosis criteria of APD among studies as well as the use of school enrollment number as the referenced population to estimate prevalence in our study. We also found a significant difference in APD prevalence depending on the school types. The findings of higher prevalence rates among the children attending private schools and higher proportion of Caucasians children referred for APD evaluation suggest that more children among those in public schools and in the Hispanic and African American groups should have been referred for an APD evaluation. Hence, the current estimate is likely an underestimate of the actual APD prevalence. The low percentage of Hispanic or African American children referred to the clinic for APD evaluations may be related to the socioeconomic status and linguistic differences among the concerned families. The results of this study raise the importance of adapting the APD test battery for children with a different linguistic background as well as increasing awareness of available clinical resources to all families in our area.

A Signal-Passing DNA-Strand-Exchange Mechanism for Active Self-Assembly of DNA Nanostructures.

DNA nanostructured tiles play an active role in their own self-assembly in the system described herein whereby they initiate a binding event that produces a cascading assembly process. We present DNA tiles that have a simple but powerful property: they respond to a binding event at one end of the tile by passing a signal across the tile to activate a binding site at the other end. This action allows sequential, virtually irreversible self-assembly of tiles and enables local communication during the self-assembly process. This localized signal-passing mechanism provides a new element of control for autonomous self-assembly of DNA nanostructures.

High precision and high yield fabrication of dense nanoparticle arrays onto DNA origami at statistically independent binding sites.

High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities.

Hierarchical Self Assembly of Patterns from the Robinson Tilings: DNA Tile Design in an Enhanced Tile Assembly Model.

We introduce a hierarchical self assembly algorithm that produces the quasiperiodic patterns found in the Robinson tilings and suggest a practical implementation of this algorithm using DNA origami tiles. We modify the abstract Tile Assembly Model, (aTAM), to include active signaling and glue activation in response to signals to coordinate the hierarchical assembly of Robinson patterns of arbitrary size from a small set of tiles according to the tile substitution algorithm that generates them. Enabling coordinated hierarchical assembly in the aTAM makes possible the efficient encoding of the recursive process of tile substitution.

Programmable in situ amplification for multiplexed imaging of mRNA expression.

In situ hybridization methods enable the mapping of mRNA expression within intact biological samples. With current approaches, it is challenging to simultaneously map multiple target mRNAs within whole-mount vertebrate embryos, representing a significant limitation in attempting to study interacting regulatory elements in systems most relevant to human development and disease. Here, we report a multiplexed fluorescent in situ hybridization method based on orthogonal amplification with hybridization chain reactions (HCR). With this approach, RNA probes complementary to mRNA targets trigger chain reactions in which fluorophore-labeled RNA hairpins self-assemble into tethered fluorescent amplification polymers. The programmability and sequence specificity of these amplification cascades enable multiple HCR amplifiers to operate orthogonally at the same time in the same sample. Robust performance is achieved when imaging five target mRNAs simultaneously in fixed whole-mount and sectioned zebrafish embryos. HCR amplifiers exhibit deep sample penetration, high signal-to-background ratios and sharp signal localization.

A statistic for local intensity differences: robustness to anisotropy and pseudo-centering and utility for detecting twinning.

A new approach to analyzing macromolecular single-crystal X-ray diffraction intensity statistics is presented. Instead of considering reflections in resolution shells, differences between local pairs of reflection intensities are taken and normalized separately. When the two reflections to be compared (having intensities I(1) and I(2), respectively) are chosen appropriately, the behavior of the parameter L = (I(1) - I(2))/(I(1) + I(2)) is insensitive to phenomena that tend to confound traditional intensity statistics, such as anisotropic diffraction and pseudo-centering. The distributions and expected values for L take simple forms when the intensity data are from ordinary crystals or from perfectly twinned specimens. The robustness of the approach is demonstrated with examples using real proteins whose diffraction data appear aberrant by other methods of intensity analysis. The new statistic is better suited than other available methods for diagnosing perfect hemihedral twinning.

Designing supramolecular protein assemblies.

Many natural proteins self-assemble, either to fulfill their biological function or as part of a pathogenic process. Biological assembly phenomena such as amyloidogenesis, domain swapping and symmetric oligomerization are inspiring new strategies for designing proteins that self-assemble to form supramolecular complexes. Recent advances include the design of novel proteins that assemble into filaments, symmetric cages and regular arrays.