Fate of Quasiparticles at High Temperature in the Correlated Metal Sr_{2}RuO_{4}

We study the temperature evolution of quasiparticles in the correlated metal Sr_{2}RuO_{4}. Our angle resolved photoemission data show that quasiparticles persist up to temperatures above 200 K, far beyond the Fermi liquid regime. Extracting the quasiparticle self-energy, we demonstrate that the quasiparticle residue Z increases with increasing temperature. Quasiparticles eventually disappear on approaching the bad metal state of Sr_{2}RuO_{4} not by losing weight but via excessive broadening from super-Planckian scattering. We further show that the Fermi surface of Sr_{2}RuO_{4}-defined as the loci where the spectral function peaks-deflates with increasing temperature. These findings are in semiquantitative agreement with dynamical mean field theory calculations.

Buried graphene heterostructures for electrostatic doping of low-dimensional materials

The fabrication and characterization of steep slope transistor devices based on low-dimensional materials requires precise electrostatic doping profiles with steep spatial gradients in order to maintain maximum control over the channel. In this proof-of-concept study we present a versatile graphene heterostructure platform with three buried individually addressable gate electrodes. The platform is based on a vertical stack of embedded titanium and graphene separated by an intermediate oxide to provide an almost planar surface. We demonstrate the functionality and advantages of the platform by exploring transfer and output characteristics at different temperatures of carbon nanotube field-effect transistors with different electrostatic doping configurations. Furthermore, we back up the concept with finite element simulations to investigate the surface potential. The presented heterostructure is an ideal platform for analysis of electrostatic doping of low-dimensional materials for novel low-power transistor devices.

Unloader bracing in osteoarthritis of the knee - Is there a direct effect on the damaged cartilage?

BACKGROUND

Unloading knee braces represent a conservative treatment option for non-pharmalogical management of unicompartmental osteoarthritis of the knee. Though there is consensus on the clinical effectiveness of unloading, the effect mechanism of bracing remains part of a debate. Our study was designed to assess the effect of unloader bracing on damaged cartilage via MRI cartilage mappings.

METHODS

Fourteen patients (7 female, 7 male, mean age 43.1 ± 9.4 years) with unicompartmental cartilage wear in knees with varus or valgus malalignment were enrolled. Clinical scores, radiographs and MR-graphic properties (T2/T2* mapping, T1 Delayed Gadolinium Enhanced MRI of the cartilage (dGEMRIC) mapping, high-resolution PDw sequences) of knee cartilage were recorded before and three months after brace use.

RESULTS

Bracing the knees for a mean of 14.4 ± 2.0 weeks (range 11 to 18 weeks) resulted in significant pain reduction (VAS changed from 5.9 ± 2.0 to 2.0 ± 1.3, p < 0.001) and improvement in knee function (KOOS increased from 42.1 ± 22.7 to 64.8 ± 18.7, p < 0.001). In the affected cartilage regions T2 relaxation times significantly decreased from 56.1 ± 11.4 ms to 46.5 ± 11.2 ms (p < 0.05). No changes in T1-dGEMRIC and T2* relaxation times, thickness or the extent of the damaged cartilage area could be detected.

CONCLUSIONS

Our results suggest, that unloader bracing improves the biochemical properties of the damaged cartilage by increasing collagen and proteoglycan concentration as well as decreasing the cartilage edema.

Insulin expression in β cells is reduced within islets before islet loss in diabetic cats

OBJECTIVES

Diabetes mellitus is a common condition that requires intensive treatment and markedly impacts the welfare of affected cats. The aim of this study was to identify diabetes mellitus-associated perturbations in the feline pancreatic islet microenvironment. The utility of "clear, unobstructed brain/body imaging cocktails and computational analysis" (CUBIC) for three-dimensional pancreatic analysis was investigated.

METHODS

Formalin-fixed paraffin-embedded tissues from cats with diabetes mellitus, or control cats without pancreatic pathology, were retrospectively identified. Immunohistochemistry for synaptophysin and ionised calcium binding adaptor molecule 1, and immunofluorescence for insulin and synaptophysin, were used to assess changes in islets. An image analysis pipeline was developed to analyse images acquired from two-dimensional immunofluorescence. CUBIC was used to optically clear selected pancreas samples before immunofluorescence and deep three-dimensional confocal microscopy.

RESULTS

Diabetic cats have a significant reduction in synaptophysin-positive islet area. Whilst islets from diabetic patients have similar numbers of β cells to islets from control cats, significantly lower intensity of insulin expression can be observed in the former. CUBIC facilitates clear visualisation of pancreatic islets in three dimensions.

CLINICAL SIGNIFICANCE

The data presented support the theory that there is a decrease in function of β cells before their destruction, suggesting a potentially significant step in the pathogenesis of feline diabetes mellitus. In parallel, we demonstrate CUBIC as a valuable new tool to visualise the shape of feline pancreatic islets and to interrogate pathology occurring in the islets of diabetic pets.

Digital Protein Detection in Bulk Solutions

Quick and accurate molecular diagnostics in protein detection can greatly benefit medicine in disease diagnosis and lead to positive patient outcomes. However, specialized equipment used in clinical laboratories often comes with trade-offs between operation and function serving a single role for very specific needs. For example, to achieve high analytical sensitivity and specificity, instruments such as high-performance liquid chromatography and/or liquid chromatography-mass spectrometry use a complex instrument design and require thorough training of the users. On the other hand, simple tests such as protein detection in urinary tract infection using dip-stick assays provide very quick results but suffer from poor analytical sensitivity. Here, we present an application study for the 3D particle counter technology, which is based on optical confocal detection in order to scan large sample volumes (0.5-3 mL) in glass cuvettes, that aims to close the gap between analytical sensitivity and turnover assay time and simplify protein detection by adopting bead-based immunoassays. Combining the 3D particle counter technology with bead-based immunoassays, a subpicomolar limit of detection-ranging from 119 to 346 fM-was achieved within 3.5-hour assay time for recombinant mouse interleukin 6 detection. As an alternative instrument to a flow cytometer, the 3D particle counter takes advantages of bead-based immunoassays and provides unique accessibility and flexibility for users.

A Protein Microarray-Based Respiratory Viral Antigen Testing Platform for COVID-19 Surveillance

High-throughput and rapid screening testing is highly desirable to effectively combat the rapidly evolving COVID-19 pandemic co-presents with influenza and seasonal common cold epidemics. Here, we present a general workflow for iterative development and validation of an antibody-based microarray assay for the detection of a respiratory viral panel: (a) antibody screening to quickly identify optimal reagents and assay conditions, (b) immunofluorescence assay design including signal amplification for low viral titers, (c) assay characterization with recombinant proteins, inactivated viral samples and clinical samples, and (d) multiplexing to detect a panel of common respiratory viruses. Using RT-PCR-confirmed SARS-CoV-2 positive and negative pharyngeal swab samples, we demonstrated that the antibody microarray assay exhibited a clinical sensitivity and specificity of 77.2% and 100%, respectively, which are comparable to existing FDA-authorized antigen tests. Moreover, the microarray assay is correlated with RT-PCR cycle threshold (Ct) values and is particularly effective in identifying high viral titers. The multiplexed assay can selectively detect SARS-CoV-2 and influenza virus, which can be used to discriminate these viral infections that share similar symptoms. Such protein microarray technology is amenable for scale-up and automation and can be broadly applied as a both diagnostic and research tool.

Pan-cancer analysis of genomic scar patterns caused by homologous repair deficiency (HRD)

Homologous repair deficiency (HRD) is present in many cancer types at variable prevalence and can indicate response to platinum-based chemotherapy and PARP inhibition. We developed a tumor classification system based on the loss of function of genes in the homologous recombination repair (HRR) pathway. To this end, somatic and germline alterations in BRCA1/2 and 140 other HRR genes were included and assessed for the impact on gene function. Additionally, information on the allelic hit type and on BRCA1 promoter hypermethylation was included. The HRDsum score including LOH, LST, and TAI was calculated for 8847 tumors of the TCGA cohort starting from genotyping data and for the subcohort of ovarian cancer also starting from WES data. Pan-cancer, deleterious BRCA1/2 alterations were detected in 4% of the tumors, while 18% of the tumors were HRD-positive (HRDsum ≥ 42). Across 33 cancer types, both BRCA1/2 alterations and HRD-positivity were most prevalent in ovarian cancer (20% and 69%). Pan-cancer, tumors with biallelic deleterious alterations in BRCA1/2 were separated strongly from tumors without relevant alterations (AUC = 0.89), while separation for tumors with monoallelic deleterious BRCA1/2 alterations was weak (AUC = 0.53). Tumors with biallelic deleterious alterations in other HHR genes were separated moderately from tumors without relevant alterations (AUC = 0.63), while separation for tumors with such monoallelic alterations was weaker (AUC = 0.57). In ovarian cancer, HRDsum scores calculated from WES data correlated strongly with HRDsum scores calculated from genotyping data (R = 0.87) and were slightly (4%) higher. We comprehensively analyzed HRD scores and their association with mutations in HRR genes in common cancer types. Our study identifies important parameters influencing HRD measurement and argues for an integration of HRDsum score with specific mutational profiles.

Leveraging Allele-Specific Expression for Therapeutic Response Gene Discovery in Glioblastoma

Glioblastoma is the most prevalent primary malignant brain tumor in adults and is characterized by poor prognosis and universal tumor recurrence. Effective glioblastoma treatments are lacking, in part due to somatic mutations and epigenetic reprogramming that alter gene expression and confer drug resistance. To investigate recurrently dysregulated genes in glioblastoma we interrogated allele-specific expression (ASE), the difference in expression between two alleles of a gene, in glioblastoma stem cells (GSC) derived from 43 patients. A total of 118 genes were found with recurrent ASE preferentially in GSCs compared to normal tissues. These genes were enriched for apoptotic regulators, including schlafen family member 11 (SLFN11). Loss of SLFN11 gene expression was associated with aberrant promoter methylation and conferred resistance to chemotherapy and PARP inhibition. Conversely, low SLFN11 expression rendered GSCs susceptible to the oncolytic flavivirus Zika. This discovery effort based upon ASE revealed novel points of vulnerability in GSCs, suggesting a potential alternative treatment strategy for chemotherapy resistant glioblastoma.

The relationship between epigenetic age and myocardial infarction/acute coronary syndrome and in a population based nested case-control study

Background

The measure of “epigenetic age” (EA) derived from DNA methylation (DNAm) is considered as biomarker of ageing.

Objective

We investigated the relationship between EA and Myocardial Infarction (MI) /Acute coronary syndrome (ACS) in a nested case-control study of the elderly population.

Methods

A random population sample was examined at baseline (2003/05, n=9360, age 45–69, the Russian arm of the HAPIEE Project), re-examined in 2006/08, 2015/17, and followed up for an average 15 years for fatal and non-fatal events. Using a nested case-control study design, we selected participants with incident MI/ACS (cases) and age-and sex-stratified controls among those free from baseline CVD. We performed DNAm profiling of the whole blood samples (using Illumina EPIC arrays) collected at baseline. After quality control, 135 cases and 185 controls were included in the analysis. Baseline EA was calculated using Horvath, Hannum, PhenoAge and Skin and Blood DNAm clocks; the differences between EA and chronological age (CA) were denoted as DAHr, DAHn, DAPh, DASB, respectively.

Results

DNAm ages calculated with Horvath's, Hannum's and Skin and Blood clocks were close to the CA; the corresponding median absolute differences (MAD) were 3.38, 3.64 and 2.79 years, and mean (SD) −0.85 (5.37), 1.96 (5.18) and 2.10 (3.94) for DAHr, DAHn and DASB respectively. As expected, PhenoAge's predictions were less precise with MAD=9.41 and DAPh mean (SD) 8.94 (6.38). The mean DAHr and DAHn were significantly higher in MI/ACS compared to controls (0.99 (5.38) vs. −1.55 (5.27), p=0.007, and 2.89 (6.37) vs. 1.28 (4.95), p=0.006 correspondingly), DASB was borderline higher in MI/ACS vs controls and DAPh was similar in cases and controls. After controlling for sex, the risk of MI/ACS was higher in DAHr terciles 2 and 3 vs. tercile 1 (OR=1.08 [95% CI 0.61–1.89], p=0.799 and OR=2.09 [1.19–3.66], p=0.010); the association was independent of smoking but it was largely explained (or mediated) by metabolic factors (blood pressure, body mass index, total and LDL-cholesterol). Similarly, the risk of MI/ACS was increased in terciles 2 and 3 of DAHn; compared with lowest tercile, the OR were 1.52 [0.86–2.71], p=0.152 and 2.41 [1.34–4.34], p=0.003), respectively; again, the association was largely explained by metabolic factors. There was no association found between baseline DAPh or DASB and the risk of MI/ACS.

Conclusion

In this case-control study nested in a prospective population-based cohort, we found an association between acceleration of epigenetic age and increased risk of MI/ACS independent of sex and smoking. The risk of MI/ACS was about 2-fold higher in the top tercile of difference between epigenetic and chronological age. The excess risk is appeared to be modulated by metabolic factors.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Russian Science Foundation; Russian Academy of Sciences, Sate Assignment

Multidisciplinary barriers to addressing tobacco cessation during an inpatient psychiatric hospitalization

Tobacco use and resultant health complications disproportionately impact individuals with psychiatric disorders. Inpatient psychiatric hospitalizations provide an opportunity to initiate tobacco treatment. In this study, electronic medical record review identified demographic and clinical information, smoking status, and tobacco cessation treatment offered for adults hospitalized on two acute, non-smoking psychiatric units in Massachusetts from January 2016 to March 2018. We additionally conducted semi-structured interviews with 15 inpatient nursing, psychiatry, psychology and social work providers regarding their tobacco cessation treatment practices and perceived facilitators and barriers to addressing tobacco use on psychiatric inpatient units. Chart review identified 1099 of 3140 (35%) people admitted reporting daily tobacco smoking. On discharge, 5 (0.005%) of inpatient smokers received a prescription for varenicline, 43 (0.04%) for dual-nicotine replacement therapy, 211 (19.2%) for nicotine patch, and 5 (0.005%) for bupropion. Barriers to inpatient smoking cessation treatment initiation identified in qualitative interviews included: 1) smoking cessation as low priority, 2) smoking cessation as the responsibility of outpatient providers, 3) lack of education about tobacco treatment, and 4) treatment discussions framed as preventing withdrawal. Given the potential to impact a large percentage of psychiatric tobacco users, future interventions should investigate provision of tobacco cessation counseling and pharmacotherapy in inpatient settings, with interventions that take into account the barriers and opportunities presented in this study.

Luminescent silicon nanoparticles for distinctive tracking of cellular targeting and trafficking

Developing therapeutic nanoparticles that actively target disease cells or tissues by exploiting the binding specificity of receptors presented on the cell surface has extensively opened up biomedical applications for drug delivery and imaging. An ideal nanoparticle for biomedical applications is required to report confirmation of relevant targeting and the ultimate fate in a physiological environment for further verification, e.g. to adapt dosage or predict response. Herein, we demonstrate tracking of silicon nanoparticles through intrinsic photoluminescence (PL) during the course of cellular targeting and uptake. Time-resolved analysis of PL characteristics in cellular microenvironments provides dynamic information on the physiological conditions where the silicon nanoparticles are exposed. In particular, the PL lifetime of the silicon nanoparticles is in the order of microseconds, which is significantly longer than the nanosecond lifetimes exhibited by fluorescent molecules naturally presented in cells, thus allowing discrimination of the nanoparticles from the cellular background autofluorescence in time-gated imaging. The PL lifetime is a physically intensive property that reports the inherent characteristics of the nanoparticles regardless of surrounding noise. Furthermore, we investigate a unique means to inform the lifespan of the biodegradable silicon nanoparticles responsive to local microenvironment in the course of endocytosis. A multivalent strategy of nanoparticles for enhanced cell targeting is also demonstrated with complementary analysis of time-resolved PL emission imaging and fluorescence correlation spectroscopy. The result presents the promising potential of the photoluminescent silicon nanoparticles toward advanced cell targeting systems that simultaneously enable tracking of cellular trafficking and tissue microenvironment monitoring.

Validation of a combined ELISA to detect IgG, IgA and IgM antibody responses to SARS-CoV-2 in mild or moderate non-hospitalised patients

BACKGROUND

Frequently SARS-CoV-2 results in mild or moderate disease with potentially lower concentrations of antibodies compared to those that are hospitalised. Here, we validated an ELISA using SARS-CoV-2 trimeric spike glycoprotein, with targeted detection of IgG, IgA and IgM (IgGAM) using serum and dried blood spots (DBS) from adults with mild or moderate disease.

METHODS

Targeting the SARS-CoV-2 trimeric spike, a combined anti-IgG, IgA and IgM serology ELISA assay was developed using 62 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 624 COVID-19 negative samples. The assay was validated using 73 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 359 COVID-19 negative serum samples with an additional 81 DBSs. The assay was further validated in 226 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 426 COVID-19 negative clinical samples.

RESULTS

A sensitivity and specificity of 98.6% (95% CI, 92.6-100.0), 98.3% (95% CI, 96.4-99.4), respectively, was observed following validation of the SARS-CoV-2 ELISA. No cross-reactivities with endemic coronaviruses or other human viruses were observed, and no change in results were recorded for interfering substances. The assay was stable at temperature extremes and components were stable for 15 days once opened. A matrix comparison showed DBS to correlate with serum results. Clinical validation of the assay reported a sensitivity of 94.7% (95% CI, 90.9-97.2%) and a specificity of 98.4% (95% CI, 96.6-99.3%).

CONCLUSIONS

The human anti-IgGAM SARS-CoV-2 ELISA provides accurate and sensitive detection of SARS-CoV-2 antibodies in non-hospitalised adults with mild or moderate disease. The use of dried blood spots makes the assay accessible to the wider community.

A Clinical-Stage Cysteine Protease Inhibitor blocks SARS-CoV-2 Infection of Human and Monkey Cells

Host-cell cysteine proteases play an essential role in the processing of the viral spike protein of SARS coronaviruses. K777, an irreversible, covalent inactivator of cysteine proteases that has recently completed phase 1 clinical trials, reduced SARS-CoV-2 viral infectivity in several host cells: Vero E6 (EC50< 74 nM), HeLa/ACE2 (4 nM), Caco-2 (EC90 = 4.3 μM), and A549/ACE2 (<80 nM). Infectivity of Calu-3 cells depended on the cell line assayed. If Calu-3/2B4 was used, EC50 was 7 nM, but in the ATCC Calu-3 cell line without ACE2 enrichment, EC50 was >10 μM. There was no toxicity to any of the host cell lines at 10-100 μM K777 concentration. Kinetic analysis confirmed that K777 was a potent inhibitor of human cathepsin L, whereas no inhibition of the SARS-CoV-2 cysteine proteases (papain-like and 3CL-like protease) was observed. Treatment of Vero E6 cells with a propargyl derivative of K777 as an activity-based probe identified human cathepsin B and cathepsin L as the intracellular targets of this molecule in both infected and uninfected Vero E6 cells. However, cleavage of the SARS-CoV-2 spike protein was only carried out by cathepsin L. This cleavage was blocked by K777 and occurred in the S1 domain of the SARS-CoV-2 spike protein, a different site from that previously observed for the SARS-CoV-1 spike protein. These data support the hypothesis that the antiviral activity of K777 is mediated through inhibition of the activity of host cathepsin L and subsequent loss of cathepsin L-mediated viral spike protein processing.

[Comparison between oral fluid samples and pooled serum samples for the detection of antibodies against Porcine Reproductive and Respiratory Syndrome Virus in weaning pig herds]

INTRODUCTION

Monitoring of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in pig farms is performed usually by testing for antibodies against PRRSV in serum samples. A new method is the detection of PRRSV antibodies in porcine saliva. In this study serum samples and saliva were collected in nine farms suspicious for PRRSV and tested for the presence of PRRSV antibodies. In total 220 serum and 41 saliva samples were taken from pigs at the age of 8 weeks (± 1 week). One saliva and one pooled serum sample (1:5) were tested from each pen. In total 11 (Cut-off 0.4/0.3) or 14 (Cut-off 0.2) serum samples and 23 saliva out of 41 pens were positive for PRRSV antibodies. Cohen`s Kappa testing showed a moderate agreement (κ = 0.446). Saliva samples compared to pooled serum samples were very sensitive, the specificity was 60 and 67, respectively.

A cysteine protease inhibitor blocks SARS-CoV-2 infection of human and monkey cells

K777 is a di-peptide analog that contains an electrophilic vinyl-sulfone moiety and is a potent, covalent inactivator of cathepsins. Vero E6, HeLa/ACE2, Caco-2, A549/ACE2, and Calu-3, cells were exposed to SARS-CoV-2, and then treated with K777. K777 reduced viral infectivity with EC50 values of inhibition of viral infection of: 74 nM for Vero E6, <80 nM for A549/ACE2, and 4 nM for HeLa/ACE2 cells. In contrast, Calu-3 and Caco-2 cells had EC50 values in the low micromolar range. No toxicity of K777 was observed for any of the host cells at 10-100 μM inhibitor. K777 did not inhibit activity of the papain-like cysteine protease and 3CL cysteine protease, encoded by SARS-CoV-2 at concentrations of ≤ 100 μM. These results suggested that K777 exerts its potent anti-viral activity by inactivation of mammalian cysteine proteases which are essential to viral infectivity. Using a propargyl derivative of K777 as an activity-based probe, K777 selectively targeted cathepsin B and cathepsin L in Vero E6 cells. However only cathepsin L cleaved the SARS-CoV-2 spike protein and K777 blocked this proteolysis. The site of spike protein cleavage by cathepsin L was in the S1 domain of SARS-CoV-2 , differing from the cleavage site observed in the SARS CoV-1 spike protein. These data support the hypothesis that the antiviral activity of K777 is mediated through inhibition of the activity of host cathepsin L and subsequent loss of viral spike protein processing.

Zika Virus Targets Glioblastoma Stem Cells through a SOX2-Integrin αvβ5 Axis

Zika virus (ZIKV) causes microcephaly by killing neural precursor cells (NPCs) and other brain cells. ZIKV also displays therapeutic oncolytic activity against glioblastoma (GBM) stem cells (GSCs). Here we demonstrate that ZIKV preferentially infected and killed GSCs and stem-like cells in medulloblastoma and ependymoma in a SOX2-dependent manner. Targeting SOX2 severely attenuated ZIKV infection, in contrast to AXL. As mechanisms of SOX2-mediated ZIKV infection, we identified inverse expression of antiviral interferon response genes (ISGs) and positive correlation with integrin α_v (ITGAV). ZIKV infection was disrupted by genetic targeting of ITGAV or its binding partner ITGB5 and by an antibody specific for integrin α_vβ₅. ZIKV selectively eliminated GSCs from species-matched human mature cerebral organoids and GBM surgical specimens, which was reversed by integrin α_vβ₅ inhibition. Collectively, our studies identify integrin α_vβ₅ as a functional cancer stem cell marker essential for GBM maintenance and ZIKV infection, providing potential brain tumor therapy.

Validation and Application of the AC2 Code COCOSYS

The GRS program package AC2 with its codes ATHLET/ATHLET-CD and COCOSYS aims for the reliable computational simulation of significant phenomena occurring during normal operation, design basis accidents, and severe accidents in the cooling circuit and containment of a nuclear power plant. To keep the modelling at the state-of-the-art, continuous development and validation is required. This is accomplished through participation in several national and international experimental research programs, where AC2 or one of its codes are assessed against both separate effect tests and integral tests. This paper exemplifies the status of validation and application of COCOSYS by means of calculations of iodine chemistry and molten corium/concrete interaction after reactor pressure vessel rupture. Further, calculations using the external 3D module CoPool coupled to COCOSYS on thermal stratification in large water pools are discussed. The examples given demonstrate the progress of the COCOSYS development and the capability to simulate phenomena in the containment during incidents and accidents with good results. Future applications comprise the entire spectrum of incidents and accidents for Generation III/III+ systems with just one program package.

[Apps in clinical use in orthopedics and trauma surgery : The status quo in Germany]

In the course of digitalization the smartphone is penetrating more and more areas of life giving the user mobile and almost ubiquitous access to the internet and other web applications. The advantages of mHealth are an integral part in some areas of patient care but in contrast to other disciplines, routine integration of mobile devices into orthopedics and trauma surgery is still in its infancy. A survey among German orthopedists and trauma surgeons revealed which kind of apps have become established in everyday clinical practice to date. Apps published by representative institutions such as the AO Foundation demonstrated the highest usage rates. In summary, the number of regularly used apps is low; however, the causes of this lack of acceptance have not yet been conclusively clarified. The authors of this study proclaim a significant increase in the use of mHealth and mobile devices in daily clinical practice in the future.

Activity of Selected Nucleoside Analogue ProTides against Zika Virus in Human Neural Stem Cells

Zika virus (ZIKV), an emerging flavivirus that causes neurodevelopmental impairment to fetuses and has been linked to Guillain-Barré syndrome continues to threaten global health due to the absence of targeted prophylaxis or treatment. Nucleoside analogues are good examples of efficient anti-viral inhibitors, and prodrug strategies using phosphate masking groups (ProTides) have been employed to improve the bioavailability of ribonucleoside analogues. Here, we synthesized and tested a small library of 13 ProTides against ZIKV in human neural stem cells. Strong activity was observed for 2′-C-methyluridine and 2′-C-ethynyluridine ProTides with an aryloxyl phosphoramidate masking group. Substitution of a 2-(methylthio) ethyl phosphoramidate for the aryloxyl phosphoramidate ProTide group of 2′-C-methyluridine completely abolished antiviral activity of the compound. The aryloxyl phosphoramidate ProTide of 2′-C-methyluridine outperformed the hepatitis C virus (HCV) drug sofosbuvir in suppression of viral titers and protection from cytopathic effect, while the former compound’s triphosphate active metabolite was better incorporated by purified ZIKV NS5 polymerase over time. These findings suggest both a nucleobase and ProTide group bias for the anti-ZIKV activity of nucleoside analogue ProTides in a disease-relevant cell model.

Mechanism of Action of Methotrexate Against Zika Virus

Zika virus (ZIKV), which is associated with microcephaly in infants and Guillain-Barré syndrome, reemerged as a serious public health threat in Latin America in recent years. Previous high-throughput screening (HTS) campaigns have revealed several potential hit molecules against ZIKV, including methotrexate (MTX), which is clinically used as an anti-cancer chemotherapy and anti-rheumatoid agent. We studied the mechanism of action of MTX against ZIKV in relation to its inhibition of dihydrofolate reductase (DHFR) in vitro using Vero and human neural stem cells (hNSCs). As expected, an antiviral effect for MTX against ZIKV was observed, showing up to 10-fold decrease in virus titer during MTX treatment. We also observed that addition of leucovorin (a downstream metabolite of DHFR pathway) rescued the ZIKV replication impaired by MTX treatment in ZIKV-infected cells, explaining the antiviral effect of MTX through inhibition of DHFR. We also found that addition of adenosine to ZIKV-infected cells was able to rescue ZIKV replication inhibited by MTX, suggesting that restriction of de novo synthesis adenosine triphosphate (ATP) pools suppresses viral replication. These results confirm that the DHFR pathway can be targeted to inhibit replication of ZIKV, similar to other published results showing this effect in related flaviviruses.

A randomized controlled proof-of-concept trial of digoxin and furosemide in adults with cutaneous warts

Background

Topical ionic contraviral therapy (ICVT) with digoxin and furosemide inhibits the potassium influx on which DNA viruses rely for replication. Therefore, ICVT was hypothesized to be a potential novel treatment for cutaneous warts.

Objectives

To assess the clinical efficacy, safety and tolerability of ICVT in adults with cutaneous warts. The secondary objective was to gain insight into the underlying working mechanism of ICVT.

Methods

Treatment with ICVT was assessed for efficacy, safety and tolerability in a single‐ centre, randomized, double‐blind, placebo‐controlled phase IIA trial. Eighty adult patients with at least two cutaneous warts (plantar or common) were randomized to one of four treatments: digoxin + furosemide (0·125%), digoxin (0·125%), furosemide (0·125%) or placebo. The gel was administered once daily for 42 consecutive days. Predefined statistical analysis was performed with a mixed‐model ancova. The trial was registered at ClinicalTrials.gov with number NCT02333643.

Results

Wart size and human papillomavirus (HPV) load reduction was achieved in all active treatment groups. A statistically significant reduction in wart diameter of all treated warts was shown in the digoxin + furosemide treatment group vs. placebo (−3·0 mm, 95% confidence interval −4·9 to −1·1, P = 0·002). There was a statistically significant reduction in the HPV load of all treated warts in the digoxin + furosemide group vs. placebo (−94%, 95% confidence interval −100 to −19, P = 0·03). With wart size reduction, histologically and immunohistochemically defined viral characteristics disappeared from partial and total responding warts.

Conclusions

This study demonstrates the proof of concept for the efficacy of topical ICVT in adults with cutaneous warts.

What's already known about this topic?

Cutaneous warts are caused by the human papillomavirus (HPV).

Ionic contraviral therapy (ICVT) might be a potential treatment for cutaneous warts.

A previous phase I/II open‐label study demonstrated the safety and efficacy of ICVT.

What does this study add?

Proof of concept for the efficacy of topical ICVT in adults with cutaneous warts.

Topical ICVT demonstrates a favourable safety profile, with the effects most pronounced when it is combined in a formulation for common warts.

Wart size reduction was related to HPV load reduction measured by quantitative polymerase chain reaction (qPCR) in swabs.

qPCR is a valuable disease biomarker for drug development in cutaneous warts.

https://doi.org/10.1111/bjd.17803 available online

https://www.bjdonline.com/article/

Validation of international consensus equation for acute serum total tryptase in mast cell activation: A perioperative perspective

There is no standardized method for assessing serum total mast cell tryptase (MCT) in anaphylaxis. The consensus equation (peak MCT should be>1.2× baseline tryptase+2 mg/L) has been proposed to interpret acute MCT in mast cell activation syndrome (MCAS). To validate consensus equation in a perioperative setting analyses of cases of suspected perioperative anaphylaxis during general anaesthesia (GA) were performed. Anaphylaxis was defined as per World Allergy Organisation (WAO) criteria. Timed serial MCT measurements were mapped against the consensus equation and receiver operating characteristic (ROC) curves produced. A total of 82 patients (60 females, mean age 56.5 years±SD17.2) underwent investigation. Sixty (73%) patients fulfilled WAO criteria for anaphylaxis, and 22 patients did not. Aetiology included 59% IgE-mediated anaphylaxis, 2% non-IgE-mediated anaphylaxis, 12% anaphylaxis of unknown cause and 27% deemed non-anaphylaxis. IgE-mediated anaphylaxis included the following: NMBA (35%), antibiotics (46%), chlorhexidine (8%), patent blue dye (8%) and others (8%). An acute MCT with a comparable baseline was available in 71 of 82 (87%) patients (60 anaphylaxis and 11 controls). The median interquartile range (IQR) time from reaction to peak MCT was 1.34 (0.82-2.51) hours. Analyses confirmed that a rise in acute MCT greater than that defined by the equation had a sensitivity, specificity, positive predictive value (PPV) and negative (N) PV of 78%, 91%, 98% and 44%, respectively. The magnitude of increase in acute MCT above the threshold predicted by consensus equation was higher in the anaphylaxis group compared to controls (P=.0001). This equation has a high specificity, PPV with a moderate NPV and sensitivity in perioperative anaphylaxis.

Decelerated neurodegeneration after intravitreal injection of α-synuclein antibodies in a glaucoma animal model

Although elevated intraocular pressure (IOP) remains the major risk factor in glaucoma, neurodegenerative processes continue despite effective IOP lowering. Altered α-synuclein antibody (Abs) levels have been reported to play a crucial role. This study aimed at identifying whether α-synuclein Abs are capable to decelerate neuronal decay while providing insights into proteomic changes. Four groups of Sprague Dawley rats received episcleral vein occlusion: (1) CTRL, no intravitreal injection, n = 6, (2) CTRL IgG, intravitreal injection of unspecific IgG, n = 5, (3) Buffer, intravitreal injection of buffer, n = 6, (4), α-synuclein Ab, intravitreal injection of α-synuclein Ab, n = 5. IOP and retinal nerve fiber layer thickness (RNFLT) were monitored and immunohistochemistry, microarray and proteomic analysis were performed. RNFLT was reduced in CTRL, CTRL IgG and Buffer group (all p < 0.01) and α-synuclein Ab group (p = 0.17). Axon and RGC density showed an increased neurodegeneration in CTRL, CTRL IgG and Buffer group (all p < 0.01) and increased neuronal survival in α-synuclein Ab group (p = 0.38 and 0.06, respectively) compared with fellow eyes. Proteomic analysis revealed alterations of cofilin 1 and superoxide dismutase 1 expression. This data indicate that α-synuclein Ab might indirectly modulate the actin cytoskeleton organization and negatively regulate apoptotic processes via cofilin 1 and superoxide dismutase 1.

Fragmentation behavior of DOTA complexes under different activation conditions

We have investigated the fragmentation behavior of a number of DOTA-metal complexes under collision-induced dissociation, infrared-multiphoton dissociation and higher-energy collisional dissociation activation conditions. Both, positive and negative ion mode electrospray ionization was applied. The results show that characteristic fragmentations were obtained for the metal-complexes under the investigated conditions. All elemental compositions of fragment ions have been unambiguously identified by high resolution-accurate mass measurements. Certain trends, for instance eliminations of carbon dioxide, alkyl and amine residues, were observed that coincide with the size of the metal and its location within the periodic table. Additionally, lanthanide, aluminium and indium species with even oxidation state or containing a radical have been detected. To further investigate the observed water capture during activation, deuterium labeling experiments have also been carried out. Copyright © 2017 John Wiley & Sons, Ltd.

Pathobiological investigation of naturally infected canine rabies cases from Sri Lanka

Background

The recommended screening of rabies in ‘suspect’ animal cases involves testing fresh brain tissue. The preservation of fresh tissue however can be difficult under field conditions and formalin fixation provides a simple alternative that may allow a confirmatory diagnosis. The occurrence and location of histopathological changes and immunohistochemical (IHC) labelling for rabies in formalin fixed paraffin embedded (FFPE) canine brain is described in samples from 57 rabies suspect cases from Sri-Lanka. The presence of Negri bodies and immunohistochemical detection of rabies virus antigen were evaluated in the cortex, hippocampus, cerebellum and brainstem. The effect of autolysis and artefactual degeneration of the tissue was also assessed.

Results

Rabies was confirmed in 53 of 57 (93%) cases by IHC. IHC labelling was statistically more abundant in the brainstem. Negri bodies were observed in 32 of 53 (60.4%) of the positive cases. Although tissue degradation had no effect on IHC diagnosis, it was associated with an inability to detect Negri bodies. In 13 cases, a confirmatory Polymerase chain reaction (PCR) testing for rabies virus RNA was undertaken by extracting RNA from fresh frozen tissue, and also attempted using FFPE samples. PCR detection using fresh frozen samples was in agreement with the IHC results. The PCR method from FFPE tissues was suitable for control material but unsuccessful in our field cases.

Conclusions

Histopathological examination of the brain is essential to define the differential diagnoses of behaviour modifying conditions in rabies virus negative cases, but it is unreliable as the sole method for rabies diagnosis, particularly where artefactual change has occurred. Formalin fixation and paraffin embedding does not prevent detection of rabies virus via IHC labelling even where artefactual degeneration has occurred. This could represent a pragmatic secondary assay for rabies diagnosis in the field because formalin fixation can prevent sample degeneration. The brain stem was shown to be the site with most viral immunoreactivity; supporting recommended sampling protocols in favour of improved necropsy safety in the field. PCR testing of formalin fixed tissue may be successful in certain circumstances as an alternative test.

Low- and high-risk human papillomavirus genotype infections in intra-anal warts in HIV-positive men who have sex with men

BACKGROUND

Anogenital warts are often presumed to represent nondysplastic or low-grade anal intraepithelial neoplasia (LGAIN). We previously demonstrated that up to 20% of intra-anal warts in HIV-positive men who have sex with men (MSM) contain regions of high-grade AIN (HGAIN).

OBJECTIVES

To determine the causative human papillomavirus (HPV) types of low- and high- grade dysplastic areas in warts from HIV-positive MSM.

METHODS

A total of 42 intra-anal warts from 41 HIV-positive MSM were graded as nondysplastic, LGAIN or HGAIN. Whole-tissue sections (WTS) were analysed with the SPF10 polymerase chain reaction/LiPA25 HPV genotyping system. If the WTS contained multiple HPV types, dysplastic regions were isolated by laser capture microdissection (LCM) for HPV genotyping.

RESULTS

Overall, 38 of 42 (91%) WTS tested positive for HPV DNA. Of these, 23 (61%) contained a single HPV type and 15 (39%) contained multiple HPV types. All LCM-selected regions contained no more than one HPV type. Ten of 42 (24%) WTS contained HGAIN disease, of which six (60%) were associated with a high-risk HPV (hrHPV) genotype. Twenty-three of 42 WTS contained LGAIN disease, of which two (9%) were associated with hrHPV. AIN lesions containing hrHPV types were identified using p16 staining.

CONCLUSIONS

LGAIN lesions can be caused by high-risk HPV genotypes and vice versa. We therefore recommend routine follow-up and treatment of all dysplastic intra-anal warts for HIV-positive MSM.

In vivo quantification of gentamicin released from an implant coating

Drug-releasing implants are gaining increasing interest. The present study reports a detailed physicochemical analysis of a polymeric coating based on poly(D,L-lactide) and the incorporated gentamicin combined with an in vitro and in vivo study of the gentamicin release. Differential scanning calorimeter, Fourier transform infrared spectroscopy, gel permeation chromatography and high-performance liquid chromatography showed no effect of the gamma sterilisation on the coating components or an interaction of the polymer and the gentamicin. Microbiological analysis revealed an inhibition of bacterial growth on the implant surface. For the in vivo study, gentamicin-coated wires were implanted into the tibiae of rats and harvested at different time points up to day 42. To monitor the release in vivo, gentamicin was quantified in serum, bone, endosteum, kidney, and on the explanted wires. Gentamicin was detectable over a time period of 42 days in the endosteum, up to seven days in the kidney, up to 4 h in the bone and at the end of the experiment on one of eight wires. The locally released gentamicin caused no histological changes of the kidney. Microbiologically active concentrations of released gentamicin were found in the endosteum up to 4 h after implantation. The combination of different methods supports the individual results, where quantification is complemented by visualisation or antimicrobial activity. This work demonstrates that the coating procedure results in no substantial alteration of the incorporated drug and that the in vitro burst release occurs also in vivo.

Volume perfusion computed tomography (VPCT)-based evaluation of response to TACE using two different sized drug eluting beads in patients with nonresectable hepatocellular carcinoma: Impact on tumor and liver parenchymal vascularisation

OBJECTIVE

Response monitoring of transarterial chemoembolization (TACE) with the help of volume perfusion computed tomography (VPCT) at day one post-TACE and analysis of TACE-impact on tumor and uninvolved liver parenchymal perfusion by using different particles sizes and epirubicin dose.

MATERIALS AND METHODS

Institutional review board approved this prospective study. VPCT was performed in the baseline, post-interventional (FU1; 24 h post-TACE) and at follow-up (FU2; median, 81 days) in 45 consecutive patients. 100-300 μm (n=17) and 300-500 μm (n=28) drug eluting beads (DEB) using an epirubicin dose of (<=25 vs. >25) were administered. VPCT was performed for 40-s using 80 kV, 100/120 mAs, 64×0.6 mm collimation, 26 consecutive measurements, IV injection (50 ml iodinated contrast), flow rate (5 ml/s). Blood flow (BF), blood volume (BV) and k-trans were registered as average and max values in the tumor. Arterial liver perfusion (ALP), portal-venous perfusion (PVP) and the hepatic perfusion index (HPI) were registered both in tumor and non-involved liver parenchyma. Response to TACE was classified by VPCT as complete (CR), partial (PR) or no response (NR).

RESULTS

A significant reduction of viable tumor tissue was found in all patients between baseline and FU1 (p<0.001) being independent on particle size and epirubicin dose (p>0.05). PPV/NPV/sensitivity/specificity of post-interventional VPCT (FU1) results for prediction of the mid-term tumor course (FU2) were 100%/70%/76%/100%. There was generally a significant increase of the ALP between baseline and FU1 in the liver parenchyma coupled by a significant subsequent decrease (normalization) of ALP and HPI between FU1 and FU2.

CONCLUSION

VPCT accurately measures impact of TACE on liver tumor and hepatic parenchymal perfusion. The former proved not to be significantly dependent on particle size and epirubicin dose. There was no persistent perfusion deficit in the liver after TACE.

Loss of oligophrenin1 leads to uncontrolled Rho activation and increased thrombus formation in mice

BACKGROUND

Platelet cytoskeletal reorganization is essential for platelet adhesion and thrombus formation in hemostasis and thrombosis. The Rho GTPases RhoA, Rac1 and Cdc42 are the main players in cytoskeletal dynamics of platelets and induce filopodia and lamellipodia formation and actin polymerization to strongly increase the platelet surface upon activation. Moreover, they are important for platelet secretion, integrin activation and arterial thrombus formation.

OBJECTIVES

Rho GTPases are regulated by GTPase-activating proteins (GAPs) that stimulate their GTPase activity to terminate Rho signaling. The regulation of Rho GTPase activity in platelets is not well defined. Recently, we identified oligophrenin1 (OPHN1), a RhoGAP in platelets that exhibits strong GTPase-stimulating activity towards RhoA, Cdc42 and Rac1.

RESULTS

In the present study we show for the first time, that deficiency of OPHN1 led to abnormal Rho activation and increased platelet cytoskeletal reorganization, including cell adhesion and lamellipodia formation on fibrinogen. Furthermore, platelets from ophn1(-/-) mice showed enhanced susceptibility to platelet activation with alterations in actin distribution and early release of granules. Platelet activation was enhanced following GPVI and PAR4 stimulation. This translated into elevated platelet thrombus formation and promoted arterial thrombosis under low shear conditions with altered hemostasis, as detected by tail bleeding time.

CONCLUSIONS

The results of the present study identified OPHN1 as an important regulator of platelet cytoskeletal reorganization and demonstrate that abnormal regulation of Rho proteins leads to increased platelet adhesion and thrombus formation under low shear conditions in vitro and in vivo, suggesting a prothrombotic phenotype of mice critical for acute thrombotic occlusions.

The LIM-only transcription factor LMO2 determines tumorigenic and angiogenic traits in glioma stem cells

Glioblastomas (GBMs) maintain their cellular heterogeneity with glioma stem cells (GSCs) producing a variety of tumor cell types. Here we interrogated the oncogenic roles of Lim domain only 2 (LMO2) in GBM and GSCs in mice and human. High expression of LMO2 was found in human patient-derived GSCs compared with the differentiated progeny cells. LMO2 is required for GSC proliferation both in vitro and in vivo, as shRNA-mediated LMO2 silencing attenuated tumor growth derived from human GSCs. Further, LMO2 is sufficient to induce stem cell characteristics (stemness) in mouse premalignant astrocytes, as forced LMO2 expression facilitated in vitro and in vivo growth of astrocytes derived from Ink4a/Arf null mice and acquisition of GSC phenotypes. A subset of mouse and human GSCs converted into vascular endothelial-like tumor cells both in vitro and in vivo, which phenotype was attenuated by LMO2 silencing and promoted by LMO2 overexpression. Mechanistically, the action of LMO2 for induction of glioma stemness is mediated by transcriptional regulation of Jagged1 resulting in activation of the Notch pathway, whereas LMO2 directly occupies the promoter regions of the VE-cadherin gene for a gain of endothelial cellular phenotype. Subsequently, selective ablation of human GSC-derived VE-cadherin-expressing cells attenuated vascular formation in mouse intracranial tumors, thereby significantly prolonging mouse survival. Clinically, LMO2 expression was elevated in GBM tissues and inversely correlated with prognosis of GBM patients. Taken together, our findings describe novel dual roles of LMO2 to induce tumorigenesis and angiogenesis, and provide potential therapeutic targets in GBMs.

Flora of Bolivia - where do we stand?

Abstract The botanical exploration of Bolivia during the last two centuries did not leave a botanical legacy in the country. Only towards the end of the 20th century Bolivia saw the start of the biology careers at its universities and the development of its own herbaria. Nowadays there are important herbaria in La Paz, Santa Cruz, Cochabamba and Sucre with collections ranging between 40,000 and 350,000 specimens. In 2014 a catalogue of the vascular flora of Bolivia was published under the auspices of the Missouri Botanical Garden, recording 15,345 species, of which 12,165 are native and 2,343 are endemic, while 694 are cultivated, 267 adventitious and 221 are naturalized. Endemic species of vascular plants add up to 2,343 species. The 286 families listed follow the APG III classification system. There are about 150 botanists in Bolivia interested in studying the country's rich flora. During a workshop organized in 2013 to promote a Flora of Bolivia, the participants established jointly a preliminary format for the taxonomic treatments. The Flora of Bolivia is planned to be an electronic, open access publication with international participation. The World Flora represents a challenge that must be tackled by circumscribing, verifying and recording all species known within our territory, and it is expected that it will have positive repercussions from and towards the ongoing Flora of Bolivia, in a similar way as the long running series of the Flora Neotropica has provided a wider picture that can be adapted and modified to fit our particular country.

[Perioperative risk assessment of geriatric patients undergoing noncardiac surgery]

BACKGROUND

Older patients more often suffer perioperative complications than younger people. Especially geriatric patients who require emergency treatment represent a high-risk group. Therefore, perioperative risk assessment supports the treatment team in identifying patients at risk and in defining the treatment plan accordingly.

MATERIALS AND METHODS

A thorough medical history and clinical examination are pivotal elements of any risk stratification. The organ-specific risk assessment is primarily used to plan the surgical and anesthesiological procedures.

RESULTS

For a comprehensive risk assessment in geriatric patients, the organ-specific risk stratification is insufficient. Assessment instruments that reflect the idiosyncrasies of multidimensional disease in geriatric patients can complement risk stratification. These should include the assessment of multimorbidity, frailty, nutrition, activities of daily living, and cognition. In addition to risk prediction, geriatric assessment has the major advantage of providing both a diagnostic and a planning perspective. This allows the implementation of supporting measures for optimal perioperative care, which is the goal of any risk stratification. Risk scores provide a global assessment, but they have their limitations in predicting individual patient risk.