Sheets of vertically aligned BaTiO₃ nanotubes reduce cell proliferation but not viability of NIH-3T3 cells

All biomaterials initiate a tissue response when implanted in living tissues. Ultimately this reaction causes fibrous encapsulation and hence isolation of the material, leading to failure of the intended therapeutic effect of the implant. There has been extensive bioengineering research aimed at overcoming or delaying the onset of encapsulation. Nanotechnology has the potential to address this problem by virtue of the ability of some nanomaterials to modulate interactions with cells, thereby inducing specific biological responses to implanted foreign materials. To this effect in the present study, we have characterised the growth of fibroblasts on nano-structured sheets constituted by BaTiO3, a material extensively used in biomedical applications. We found that sheets of vertically aligned BaTiO3 nanotubes inhibit cell cycle progression - without impairing cell viability - of NIH-3T3 fibroblast cells. We postulate that the 3D organization of the material surface acts by increasing the availability of adhesion sites, promoting cell attachment and inhibition of cell proliferation. This finding could be of relevance for biomedical applications designed to prevent or minimize fibrous encasement by uncontrolled proliferation of fibroblastic cells with loss of material-tissue interface underpinning long-term function of implants

Mesodynamics in the SARS nucleocapsid measured by NMR field cycling

Protein motions on all timescales faster than molecular tumbling are encoded in the spectral density. The dissection of complex protein dynamics is typically performed using relaxation rates determined at high and ultra-high field. Here we expand this range of the spectral density to low fields through field cycling using the nucleocapsid protein of the SARS coronavirus as a model system. The field-cycling approach enables site-specific measurements of R1 at low fields with the sensitivity and resolution of a high-field magnet. These data, together with high-field relaxation and heteronuclear NOE, provide evidence for correlated rigid-body motions of the entire β-hairpin, and corresponding motions of adjacent loops with a time constant of 0.8 ns (mesodynamics). MD simulations substantiate these findings and provide direct verification of the time scale and collective nature of these motions

Genotyping of Bacillus cereus Strains by Microarray-Based Resequencing

The ability to distinguish microbial pathogens from closely related but nonpathogenic strains is key to understanding the population biology of these organisms. In this regard, Bacillus anthracis, the bacterium that causes inhalational anthrax, is of interest because it is closely related and often difficult to distinguish from other members of the B. cereus group that can cause diverse diseases. We employed custom-designed resequencing arrays (RAs) based on the genome sequence of Bacillus anthracis to generate 422 kb of genomic sequence from a panel of 41 Bacillus cereus sensu lato strains. Here we show that RAs represent a “one reaction” genotyping technology with the ability to discriminate between highly similar B. anthracis isolates and more divergent strains of the B. cereus s.l. Clade 1. Our data show that RAs can be an efficient genotyping technology for pre-screening the genetic diversity of large strain collections to selected the best candidates for whole genome sequencing

Abnormal Brain Iron Homeostasis in Human and Animal Prion Disorders

Neurotoxicity in all prion disorders is believed to result from the accumulation of PrP-scrapie (PrPSc), a β-sheet rich isoform of a normal cell-surface glycoprotein, the prion protein (PrPC). Limited reports suggest imbalance of brain iron homeostasis as a significant associated cause of neurotoxicity in prion-infected cell and mouse models. However, systematic studies on the generality of this phenomenon and the underlying mechanism(s) leading to iron dyshomeostasis in diseased brains are lacking. In this report, we demonstrate that prion disease–affected human, hamster, and mouse brains show increased total and redox-active Fe (II) iron, and a paradoxical increase in major iron uptake proteins transferrin (Tf) and transferrin receptor (TfR) at the end stage of disease. Furthermore, examination of scrapie-inoculated hamster brains at different timepoints following infection shows increased levels of Tf with time, suggesting increasing iron deficiency with disease progression. Sporadic Creutzfeldt-Jakob disease (sCJD)–affected human brains show a similar increase in total iron and a direct correlation between PrP and Tf levels, implicating PrPSc as the underlying cause of iron deficiency. Increased binding of Tf to the cerebellar Purkinje cell neurons of sCJD brains further indicates upregulation of TfR and a phenotype of neuronal iron deficiency in diseased brains despite increased iron levels. The likely cause of this phenotype is sequestration of iron in brain ferritin that becomes detergent-insoluble in PrPSc-infected cell lines and sCJD brain homogenates. These results suggest that sequestration of iron in PrPSc–ferritin complexes induces a state of iron bio-insufficiency in prion disease–affected brains, resulting in increased uptake and a state of iron dyshomeostasis. An additional unexpected observation is the resistance of Tf to digestion by proteinase-K, providing a reliable marker for iron levels in postmortem human brains. These data implicate redox-iron in prion disease–associated neurotoxicity, a novel observation with significant implications for prion disease pathogenesis

The efficacy and safety of a new fixed-dose combination of amodiaquine and artesunate in young African children with acute uncomplicated Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>Artesunate (AS) plus amodiaquine (AQ) is one artemisinin-based combination (ACT) recommended by the WHO for treating <it>Plasmodium falciparum </it>malaria. Fixed-dose AS/AQ is new, but its safety and efficacy are hitherto untested.</p> <p>Methods</p> <p>A randomized, open-label trial was conducted comparing the efficacy (non-inferiority design) and safety of fixed (F) dose AS (25 mg)/AQ (67.5 mg) to loose (L) AS (50 mg) + AQ (153 mg) in 750, <it>P</it>. <it>falciparum</it>-infected children from Burkina Faso aged 6 months to 5 years. Dosing was by age. Primary efficacy endpoint was Day (D) 28, PCR-corrected, parasitological cure rate. Recipients of rescue treatment were counted as failures and new infections as cured. Documented, common toxicity criteria (CTC) graded adverse events (AEs) defined safety.</p> <p>Results</p> <p>Recruited and evaluable children numbered 750 (375/arm) and 682 (90.9%), respectively. There were 8 (AS/AQ) and 6 (AS+AQ) early treatment failures and one D7 failure (AS+AQ). Sixteen (AS/AQ) and 12 (AS+AQ) patients had recurrent parasitaemia (PCR new infections 10 and 6, respectively). Fourteen patients per arm required rescue treatment for vomiting/spitting out study drugs. Efficacy rates were 92.1% in both arms: AS/AQ = 315/342 (95% CI: 88.7–94.7) vs. AS+AQ = 313/340 (95% CI: 88.6–94.7). Non-inferiority was demonstrated at two-sided α = 0.05: Δ (AS+AQ – AS/AQ) = 0.0% (95% CI: -4.1% to 4.0%). D28, Kaplan Meier PCR-corrected cure rates (all randomized children) were similar: 93.7% (AS/AQ) vs. 93.2% (AS+AQ) Δ = -0.5 (95% CI -4.2 to 3.0%). By D2, both arms had rapid parasite (F & L, 97.8% aparasitaemic) and fever (97.2% [F], 96.0% [L] afebrile) clearances.</p> <p>Both treatments were well tolerated. Drug-induced vomiting numbered 8/375 (2.1%) and 6/375 (1.6%) in the fixed and loose arms, respectively (<it>p </it>= 0.59). One patient developed asymptomatic, CTC grade 4 hepatitis (AST 1052, ALT 936). Technical difficulties precluded the assessment and risk of neutropaenia for all patients.</p> <p>Conclusion</p> <p>Fixed dose AS/AQ was efficacious and well tolerated. These data support the use of this new fixed dose combination for treating <it>P. falciparum </it>malaria with continued safety monitoring.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN07576538</p

Temporal Dynamics of Host Molecular Responses Differentiate Symptomatic and Asymptomatic Influenza A Infection

Exposure to influenza viruses is necessary, but not sufficient, for healthy human hosts to develop symptomatic illness. The host response is an important determinant of disease progression. In order to delineate host molecular responses that differentiate symptomatic and asymptomatic Influenza A infection, we inoculated 17 healthy adults with live influenza (H3N2/Wisconsin) and examined changes in host peripheral blood gene expression at 16 timepoints over 132 hours. Here we present distinct transcriptional dynamics of host responses unique to asymptomatic and symptomatic infections. We show that symptomatic hosts invoke, simultaneously, multiple pattern recognition receptors-mediated antiviral and inflammatory responses that may relate to virus-induced oxidative stress. In contrast, asymptomatic subjects tightly regulate these responses and exhibit elevated expression of genes that function in antioxidant responses and cell-mediated responses. We reveal an ab initio molecular signature that strongly correlates to symptomatic clinical disease and biomarkers whose expression patterns best discriminate early from late phases of infection. Our results establish a temporal pattern of host molecular responses that differentiates symptomatic from asymptomatic infections and reveals an asymptomatic host-unique non-passive response signature, suggesting novel putative molecular targets for both prognostic assessment and ameliorative therapeutic intervention in seasonal and pandemic influenza

Comparative Analysis of Expressed Sequence Tag (EST) Libraries in the Seagrass Zostera marina Subjected to Temperature Stress

Global warming is associated with increasing stress and mortality on temperate seagrass beds, in particular during periods of high sea surface temperatures during summer months, adding to existing anthropogenic impacts, such as eutrophication and habitat destruction. We compare several expressed sequence tag (EST) in the ecologically important seagrass Zostera marina (eelgrass) to elucidate the molecular genetic basis of adaptation to environmental extremes. We compared the tentative unigene (TUG) frequencies of libraries derived from leaf and meristematic tissue from a control situation with two experimentally imposed temperature stress conditions and found that TUG composition is markedly different among these conditions (all P < 0.0001). Under heat stress, we find that 63 TUGs are differentially expressed (d.e.) at 25°C compared with lower, no-stress condition temperatures (4°C and 17°C). Approximately one-third of d.e. eelgrass genes were characteristic for the stress response of the terrestrial plant model Arabidopsis thaliana. The changes in gene expression suggest complex photosynthetic adjustments among light-harvesting complexes, reaction center subunits of photosystem I and II, and components of the dark reaction. Heat shock encoding proteins and reactive oxygen scavengers also were identified, but their overall frequency was too low to perform statistical tests. In all conditions, the most abundant transcript (3–15%) was a putative metallothionein gene with unknown function. We also find evidence that heat stress may translate to enhanced infection by protists. A total of 210 TUGs contain one or more microsatellites as potential candidates for gene-linked genetic markers. Data are publicly available in a user-friendly database at http://www.uni-muenster.de/Evolution/ebb/Services/zostera

Role of X11 and ubiquilin as In Vivo Regulators of the Amyloid Precursor Protein in Drosophila

The Amyloid Precursor Protein (APP) undergoes sequential proteolytic cleavages through the action of β- and γ-secretase, which result in the generation of toxic β-amyloid (Aβ) peptides and a C-terminal fragment consisting of the intracellular domain of APP (AICD). Mutations leading to increased APP levels or alterations in APP cleavage cause familial Alzheimer's disease (AD). Thus, identification of factors that regulate APP steady state levels and/or APP cleavage by γ-secretase is likely to provide insight into AD pathogenesis. Here, using transgenic flies that act as reporters for endogenous γ-secretase activity and/or APP levels (GAMAREP), and for the APP intracellular domain (AICDREP), we identified mutations in X11L and ubiquilin (ubqn) as genetic modifiers of APP. Human homologs of both X11L (X11/Mint) and Ubqn (UBQLN1) have been implicated in AD pathogenesis. In contrast to previous reports, we show that overexpression of X11L or human X11 does not alter γ-secretase cleavage of APP or Notch, another γ-secretase substrate. Instead, expression of either X11L or human X11 regulates APP at the level of the AICD, and this activity requires the phosphotyrosine binding (PTB) domain of X11. In contrast, Ubqn regulates the levels of APP: loss of ubqn function leads to a decrease in the steady state levels of APP, while increased ubqn expression results in an increase in APP levels. Ubqn physically binds to APP, an interaction that depends on its ubiquitin-associated (UBA) domain, suggesting that direct physical interactions may underlie Ubqn-dependent regulation of APP. Together, our studies identify X11L and Ubqn as in vivo regulators of APP. Since increased expression of X11 attenuates Aβ production and/or secretion in APP transgenic mice, but does not act on γ-secretase directly, X11 may represent an attractive therapeutic target for AD

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research