Finite element analysis for normal pressure hydrocephalus: The effects of the integration of sulci.

Finite element analysis (FEA) is increasingly used to investigate the brain under various pathological changes. Although FEA has been used to study hydrocephalus for decades, previous studies have primarily focused on ventriculomegaly. The present study aimed to investigate the pathologic changes regarding sulcal deformation in normal pressure hydrocephalus (NPH). Two finite element (FE) models-an anatomical brain geometric (ABG) model and the conventional simplified brain geometric (SBG) model-of NPH were constructed. The models were constructed with identical boundary conditions but with different geometries. The ABG model contained details of the sulci geometry, whereas these details were omitted from the SBG model. The resulting pathologic changes were assessed via four biomechanical parameters: pore pressure, von Mises stress, pressure, and void ratio. NPH was induced by increasing the transmantle pressure gradient (TPG) from 0 to a maximum of 2.0 mmHg. Both models successfully simulated the major features of NPH (i.e., ventriculomegaly and periventricular lucency). The changes in the biomechanical parameters with increasing TPG were similar between the models. However, the SBG model underestimated the degree of stress across the cerebral mantle by 150% compared with the ABG model. The SBG model also overestimates the degree of ventriculomegaly (increases of 194.5% and 154.1% at TPG = 2.0 mmHg for the SBG and ABG models, respectively). Including the sulci geometry in a FEA for NPH clearly affects the overall results. The conventional SBG model is inferior to the ABG model, which accurately simulated sulcal deformation and the consequent effects on cortical or subcortical structures. The inclusion of sulci in future FEA for the brain is strongly advised, especially for models used to investigate space-occupying lesions.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2013R1A1A1004827).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.media.2015.05.00

High Quality Bioreplication of Intricate nanostructures from a Fragile Gecko Skin Surface with Bactericidal Properties

published_or_final_versio

One genome, multiple phenotypes: decoding the evolution and mechanisms of environmentally induced developmental plasticity in insects

Plasticity in developmental processes gives rise to remarkable environmentally induced phenotypes. Some of the most striking and well-studied examples of developmental plasticity are seen in insects. For example, beetle horn size responds to nutritional state, butterfly eyespots are enlarged in response to temperature and humidity, and environmental cues also give rise to the queen and worker castes of eusocial insects. These phenotypes arise from essentially identical genomes in response to an environmental cue during development. Developmental plasticity is taxonomically widespread, affects individual fitness, and may act as a rapid-response mechanism allowing individuals to adapt to changing environments. Despite the importance and prevalence of developmental plasticity, there remains scant mechanistic understanding of how it works or evolves. In this review, we use key examples to discuss what is known about developmental plasticity in insects and identify fundamental gaps in the current knowledge. We highlight the importance of working towards a fully integrated understanding of developmental plasticity in a diverse range of species. Furthermore, we advocate for the use of comparative studies in an evo-devo framework to address how developmental plasticity works and how it evolves

No association between islet cell antibodies and coxsackie B, mumps, rubella and cytomegalovirus antibodies in non-diabetic individuals aged 7–19 years

Viral antibodies were tested in a cohort of 44 isletcell antibody-positive individuals age 7–19 years, and 44 of their islet cell antibody-negative age and sex-matched classmates selected from a population study of 4208 pupils who had been screened for islet cell antibodies. Anti-coxsackie B1-5 IgM responses were detected in 14 of 44 (32%) of the islet cell antibody-positive subjects and in 7 of 44 (16%) control subjects. This difference did not reach the level of statistical significance. None of the islet cell antibody-positive subjects had specific IgM antibodies to mumps, rubella, or cytomegalovirus. There was also no increase in the prevalence or the mean titres of anti-mumps-IgG or IgA and anti-cytomegalovirus-IgG in islet cell antibody-positive subjects compared to control subjects. These results do not suggest any association between islet cell antibodies, and possibly insulitis, with recent mumps, rubella or cytomegalo virus infection. Further studies are required to clarify the relationship between islet cell antibodies and coxsackie B virus infections

Combinations of β-lactam or aminoglycoside antibiotics with plectasin are synergistic against methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

Bacterial infections remain the leading killer worldwide which is worsened by the continuous emergence of antibiotic resistance. In particular, methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and the latter can be difficult to treat. The traditional strategy of novel therapeutic drug development inevitably leads to emergence of resistant strains, rendering the new drugs ineffective. Therefore, rejuvenating the therapeutic potentials of existing antibiotics offers an attractive novel strategy. Plectasin, a defensin antimicrobial peptide, potentiates the activities of other antibiotics such as β-lactams, aminoglycosides and glycopeptides against MSSA and MRSA. We performed in vitro and in vivo investigations to test against genetically diverse clinical isolates of MSSA (n = 101) and MRSA (n = 115). Minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. The effects of combining plectasin with β-lactams, aminoglycosides and glycopeptides were examined using the chequerboard method and time kill curves. A murine neutropenic thigh model and a murine peritoneal infection model were used to test the effect of combination in vivo. Determined by factional inhibitory concentration index (FICI), plectasin in combination with aminoglycosides (gentamicin, neomycin or amikacin) displayed synergistic effects in 76-78% of MSSA and MRSA. A similar synergistic response was observed when plectasin was combined with β-lactams (penicillin, amoxicillin or flucloxacillin) in 87-89% of MSSA and MRSA. Interestingly, no such interaction was observed when plectasin was paired with vancomycin. Time kill analysis also demonstrated significant synergistic activities when plectasin was combined with amoxicillin, gentamicin or neomycin. In the murine models, plectasin at doses as low as 8 mg/kg augmented the activities of amoxicillin and gentamicin in successful treatment of MSSA and MRSA infections. We demonstrated that plectasin strongly rejuvenates the therapeutic potencies of existing antibiotics in vitro and in vivo. This is a novel strategy that can have major clinical implications in our fight against bacterial infections

Luteolin decreases IGF-II production and downregulates insulin-like growth factor-I receptor signaling in HT-29 human colon cancer cells

<p>Abstract</p> <p>Background</p> <p>Luteolin is a 3',4',5,7-tetrahydroxyflavone found in various fruits and vegetables. We have shown previously that luteolin reduces HT-29 cell growth by inducing apoptosis and cell cycle arrest. The objective of this study was to examine whether luteolin downregulates the insulin-like growth factor-I receptor (IGF-IR) signaling pathway in HT-29 cells.</p> <p>Methods</p> <p>In order to assess the effects of luteolin and/or IGF-I on the IGF-IR signaling pathway, cells were cultured with or without 60 μmol/L luteolin and/or 10 nmol/L IGF-I. Cell proliferation, DNA synthesis, and IGF-IR mRNA levels were evaluated by a cell viability assay, [³H]thymidine incorporation assays, and real-time polymerase chain reaction, respectively. Western blot analyses, immunoprecipitation, and <it>in vitro </it>kinase assays were conducted to evaluate the secretion of IGF-II, the protein expression and activation of IGF-IR, and the association of the p85 subunit of phophatidylinositol-3 kinase (PI3K) with IGF-IR, the phosphorylation of Akt and extracellular signal-regulated kinase (ERK)1/2, and cell division cycle 25c (CDC25c), and PI3K activity.</p> <p>Results</p> <p>Luteolin (0 - 60 μmol/L) dose-dependently reduced the IGF-II secretion of HT-29 cells. IGF-I stimulated HT-29 cell growth but did not abrogate luteolin-induced growth inhibition. Luteolin reduced the levels of the IGF-IR precursor protein and IGF-IR transcripts. Luteolin reduced the IGF-I-induced tyrosine phosphorylation of IGF-IR and the association of p85 with IGF-IR. Additionally, luteolin inhibited the activity of PI3K activity as well as the phosphorylation of Akt, ERK1/2, and CDC25c in the presence and absence of IGF-I stimulation.</p> <p>Conclusions</p> <p>The present results demonstrate that luteolin downregulates the activation of the PI3K/Akt and ERK1/2 pathways via a reduction in IGF-IR signaling in HT-29 cells; this may be one of the mechanisms responsible for the observed luteolin-induced apoptosis and cell cycle arrest.</p

DNA Structure Modulates the Oligomerization Properties of the AAV Initiator Protein Rep68

Rep68 is a multifunctional protein of the adeno-associated virus (AAV), a parvovirus that is mostly known for its promise as a gene therapy vector. In addition to its role as initiator in viral DNA replication, Rep68 is essential for site-specific integration of the AAV genome into human chromosome 19. Rep68 is a member of the superfamily 3 (SF3) helicases, along with the well-studied initiator proteins simian virus 40 large T antigen (SV40-LTag) and bovine papillomavirus (BPV) E1. Structurally, SF3 helicases share two domains, a DNA origin interaction domain (OID) and an AAA+ motor domain. The AAA+ motor domain is also a structural feature of cellular initiators and it functions as a platform for initiator oligomerization. Here, we studied Rep68 oligomerization in vitro in the presence of different DNA substrates using a variety of biophysical techniques and cryo-EM. We found that a dsDNA region of the AAV origin promotes the formation of a complex containing five Rep68 subunits. Interestingly, non-specific ssDNA promotes the formation of a double-ring Rep68, a known structure formed by the LTag and E1 initiator proteins. The Rep68 ring symmetry is 8-fold, thus differing from the hexameric rings formed by the other SF3 helicases. However, similiar to LTag and E1, Rep68 rings are oriented head-to-head, suggesting that DNA unwinding by the complex proceeds bidirectionally. This novel Rep68 quaternary structure requires both the DNA binding and AAA+ domains, indicating cooperativity between these regions during oligomerization in vitro. Our study clearly demonstrates that Rep68 can oligomerize through two distinct oligomerization pathways, which depend on both the DNA structure and cooperativity of Rep68 domains. These findings provide insight into the dynamics and oligomeric adaptability of Rep68 and serve as a step towards understanding the role of this multifunctional protein during AAV DNA replication and site-specific integration

Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

<p>Abstract</p> <p>Background</p> <p>3,3'-Diindolylmethane (DIM), an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both <it>in vivo </it>and <it>in vitro </it>models. We have previously determined that DIM (0 – 30 μmol/L) inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells.</p> <p>Methods</p> <p>HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L) and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [³H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and <it>in vitro </it>kinase assays for cyclin-dependent kinase (CDK) and cell division cycle (CDC)2 were conducted.</p> <p>Results</p> <p>The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb) and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21^CIP1/WAF1and p27^KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1.</p> <p>Conclusion</p> <p>Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.</p

Understanding economic evidence for the prevention and treatment of atopic eczema

Background Atopic eczema is an inflammatory skin condition, with a similar impact on health-related quality-of-life as other chronic diseases. Increasing pressures on resources within the NHS increase the importance of having good economic evidence to inform their allocation. This paper aims to educate dermatologists about economic methods with illustration to currently available economic evidence on eczema. Methods/design The type and role of different types of economic evidence is illustrated by evidence found in a systematic literature search conducted across 12 online databases published until 22nd May 2017. Primary empirical studies either reporting the results of a cost of illness study or evaluating the cost, utility or full economic evaluation of interventions for preventing or treating eczema were included. Two reviewers independently assessed studies for eligibility and performed data abstraction, with disagreements resolved by a third reviewer. Evidence tables of results were produced for narrative discussion. The reporting quality of economic evaluations was assessed. Results 78 studies (described in 80 papers) were deemed eligible. 33 (42%) were judged to be economic evaluations, 12 (15%) cost analyses, 6 (8%) utility analyses, 26 (34%) cost-of-illness studies and 1 feasibility study (1%). The calcineurin inhibitors: tacrolimus and pimecrolimus, as well as barrier creams had most economic evidence available. Partially hydrolysed infant formula was the most commonly evaluated prevention. Conclusions The current level of economic evidence for interventions aimed at preventing and treating eczema is limited compared to that available for clinical outcomes suggesting that greater collaboration between clinicians and economists might be beneficial