A new human hereditary amyloidosis: the result of a stop-codon mutation in the apolipoprotein AII gene

Hereditary systemic amyloidosis may be caused by mutations in a number of plasma proteins including transthyretin, apolipoprotein AI, fibrinogen Aalpha-chain, lysozyme, and gelsolin. Each type of amyloidosis is inherited as an autosomal dominant disease and is associated with a structurally altered protein that aggregates to form amyloid fibrils. Here we report that the amyloid protein in a family with previously uncharacterized hereditary renal amyloidosis is apolipoprotein AII (apoAII) with a 21-residue peptide extension on the carboxyl terminus. Sequence analysis of the apoAII gene of affected individuals showed heterozygosity for a single base substitution in the apoAII stop codon. The mutation results in extension of translation to the next in-frame stop codon 60 nucleotides downstream and is predicted to give a 21-residue C-terminal extension of the apoAII protein identical to that found in the amyloid. This mutation produces a novel BstNI restriction site that can be used to identify individuals with this gene by restriction fragment length polymorphism analysis. This is the first report of apoAII amyloid in humans and the first mutation identified in apoAII protein. Amyloid fibril formation from apoAII suggests that this lipoprotein, which is predicted to have an amphipathic helical structure, must undergo a transition to a beta-pleated sheet by a mechanism shared by other lipoproteins that form amyloid.     

Interactions between perennial ryegrass ( Lolium perenne L.) and white clover (Trifolium repens L.) under contrasting nitrogen availability: productivity,seasonal patterns of species composition,N2 fixation,N transfer and N recovery

Nitrogen (N) fertiliser and clover cultivar choice affect competition and productivity in grass-clover mixtures. Pure stands and mixtures of perennial ryegrass and white clover cultivars with contrasting growth habits were examined. The aim of this work was to study the effect of repetitive nitrogen (N) application and cultivar combination on competition and productivity, N yield in the harvested herbage, N₂ fixation in mixtures and pure stands, and transfer of N from clover to the companion grass. Large-leaved white clover cultivar Alice and small-leaved cv. Gwenda and perennial ryegrass cvs. Barlet (erect) and Heraut (prostrate) were sown in pure stands and as four binary grass-clover mixtures on a sandy soil in 1995. In the mixtures, two levels of N fertiliser were applied: 0 (-N) and 150 and 180 kg ha^-1 y^-1 N (+N) in 1996 and 1997, respectively, while the grass monocultures received three N levels (0, 140/180 and 280/360 kg ha^-1) in 1996 and 1997, respectively. No N was applied to pure clover. The plots were cut five times during 1996 and six times during 1997. Fertiliser N was applied in early spring and after every harvest. The treatments were continued until the summer of 1999. In pure grass, the applied N was effectively recovered. In mixtures, N application affected competition by enhancing grass growth and the overall effect of N application was 17 kg DM per kg N applied in 1996. However, there was no yield response to N fertilizer in 1997, because this was compensated for by a higher clover production in unfertilised mixtures. In 1997, -N mixtures yielded more N than +N mixtures, owing to the higher clover content and N₂ fixation. Large-leaved clover cv. Alice was better able to withstand the negative effect of repetitive N application on clover production in mixtures and increased its proportion during the growing season of the second harvest year. In 1997, mixtures with Alice yielded more N than mixtures with Gwenda, but in pure clover swards, there was no cultivar effect on N yield. Also, during the autumn of 1998 and the spring of 1999, the clover content was highest in mixtures with Alice. Harvested N and apparent N₂ fixation were almost twice as high in 1997 as in 1996. N yield and apparent N₂ fixation were higher in pure clover than in mixtures. In mixtures, the apparent N₂ fixation in 1996 was 142 kg N ha^-1, irrespective of cultivar or N treatment. In 1997, it was on average 337 kg N ha^-1, and higher in -N mixtures and in mixtures with Alice. For each tonne of clover DM in the harvested herbage, 65 and 57 kg N was harvested in 1996 and 1997 in -N mixtures, respectively. The apparent transfer of clover-derived N to grass was on average 29 and 70 kg N ha^-1 yr^-1 in 1996 and 1997, respectively. It was highest in +N mixtures and highest in mixtures with Gwenda in 1997. In contrast to clover, the grass cultivars were very similar in their productivity and seasonal patterns, despite their contrasting growth habits. Seasonal trends in N yield, N transfer and N recovery are discussed in relation to fertilizer application regimes and variation in production patterns in mixtures and pure stands. This revised version was published online in June 2006 with corrections to the Cover Date.     

Size-Dependent Effects of Gold Nanoparticles Uptake on Maturation and Antitumor Functions of Human Dendritic Cells In Vitro

Gold nanoparticles (GNPs) are claimed as outstanding biomedical tools for cancer diagnostics and photo-thermal therapy, but without enough evidence on their potentially adverse immunological effects. Using a model of human dendritic cells (DCs), we showed that 10 nm- and 50 nm-sized GNPs (GNP₁₀ and GNP₅₀, respectively) were internalized predominantly via dynamin-dependent mechanisms, and they both impaired LPS-induced maturation and allostimulatory capacity of DCs, although the effect of GNP₁₀ was more prominent. However, GNP₁₀ inhibited LPS-induced production of IL-12p70 by DCs, and potentiated their Th2 polarization capacity, while GNP₅₀ promoted Th17 polarization. Such effects of GNP₁₀ correlated with a stronger inhibition of LPS-induced changes in Ca²⁺ oscillations, their higher number per DC, and more frequent extra-endosomal localization, as judged by live-cell imaging, proton, and electron microscopy, respectively. Even when released from heat-killed necrotic HEp-2 cells, GNP₁₀ inhibited the necrotic tumor cell-induced maturation and functions of DCs, potentiated their Th2/Th17 polarization capacity, and thus, impaired the DCs'' capacity to induce T cell-mediated anti-tumor cytotoxicity in vitro. Therefore, GNP₁₀ could potentially induce more adverse DC-mediated immunological effects, compared to GNP₅₀.     

Antioxidant Lactobacilli Could Protect Gingival Fibroblasts Against Hydrogen Peroxide: A Preliminary In Vitro Study

Oxidative stress and tissue destruction are at the heart of periodontal diseases. The dental research area is geared toward the prevention of free radicals by nutrient antioxidants. Lactic acid bacteria (LAB) have recently attracted attention in alternative dental therapies. We aimed at highlighting the antioxidative property of Lactobacilli and Bifidobacterium strains and at determining their protective effect on gingival fibroblasts (GFs). Two Lactobacilli and 2 Bifidobacterium strains were screened for their exopolysaccharide (EPSs) production. Antioxidative assays were conducted by spectrophotometer analysis. Resistance to different concentrations of hydrogen peroxide (H₂O₂) was determined by the serial dilution technique. The protective effect of strains on GFs on hydrogen peroxide exposure was also examined by a new trypan blue exclusion assay method. Bifidobacterium breve A28 showed the highest EPS production (122 mg/l) and remarkable antioxidant activity, which were demonstrated by its ability to scavenge 72 % α,α-diphenyl-1-picrylhydrazyl free radical and chelate 88 % of iron ion, respectively. Inhibition of lipid peroxidation was determined as 71 % for the A28 strain. We suggest that LAB with antioxidative activity could be a good natural therapy agent for periodontal disorders.     

A Co-Culture Model of the Developing Small Intestine Offers New Insight in the Early Immunomodulation of Enterocytes and Macrophages by Lactobacillus spp. through STAT1 and NF-kB p65 Translocation

The early establishment of a complete microbiome has been shown to play an integral part in the development and maintenance of an intact intestine and its immune system, although much remains unknown about the specific mechanisms of immune modulation in newborns. In our study we show in a co-culture model of the undeveloped small intestine that members of Lactobacillus spp. influence STAT1 and NF-kB p65 nuclear translocation in both intestinal epithelial cells as well as underlying macrophages. Moreover, by using imaging flow cytometry we were able to monitor each individual cell and create a framework of the percentage of cells in which translocation occurred in challenged versus control cell populations. We also observed a significant difference in baseline translocation in intestinal cells when cultured alone versus those in a co-culture model, underpinning the importance of 3D models over monolayer set-ups in epithelial in vitro research. In conclusion, our work offers new insights into the potential routes by which the commensal microbiome primes the early immune system to fight pathogens, and shows how strain-specific these mechanisms really are.     

An investigation on the expression of miRNAs including miR-144 and miR-34a in plasma samples of RET-positive and RET-negative medullar thyroid carcinoma patients

Medullary thyroid carcinoma (MTC) is a scarce cancerous disease, originating from parafollicular C cells of the thyroid gland. MTC can be manifested as an aggressive carcinoma with metastasis, especially in sporadic forms. Mutations of the rearranged during transfection (RET) proto-oncogene occurs in all hereditary and a few somatic MTCs, so detection of RET mutations is needed for prompt and appropriate treatment. MicroRNAs (miRNAs) are noncoding regulatory RNAs. Extensive studies have done in progress or suppression of several types of cancers such as MTCs with the remarkable application as prognostic markers. Of the effective miRNAs in cancers, miR-144 and miR-34 were evaluated in our study. Blood samples of 25 RET-positive and 25 RET-negative blood samples of patients with MTC were evaluated for these miRNAs, using quantitative real-time polymerase chain reaction (RT-qPCR). Analysis of the results was performed by the 2 ^−ΔΔCt method, showing that miR-144 and miR-34a expression had a relative increase in patients with MTC compared with normal control samples and also in RET positives versus RET negatives. We recruited 50 out of 350 MTC plasma samples (27 female and 23 male) which were selected based on RET mutation in exon 11 (25 RET-positive and 25 RET-negative), with a mean ± SD age of 37.04 ± 1.74 years. Receiver operating characteristic (ROC) curve analysis was done to investigate the prognostic value of these miRNAs; although, they showed no significant prognostic value as MTC biomarkers in plasma samples. In conclusion, miRNAs can be used as biomarkers of cancers such as MTC; however, more studies are needed to find the best candidate miRNAs for the diagnosis of cancers.     

Horizontally Acquired Glycosyltransferase Operons Drive Salmonellae Lipopolysaccharide Diversity

The immunodominant lipopolysaccharide is a key antigenic factor for Gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. Variation in the lipopolysaccharide is also the major differentiating factor that is used to classify Salmonella into over 2600 serovars as part of the Kaufmann-White scheme. While lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis operon, extraneous genetic factors such as those encoded by the glucosyltransferase (gtr) operons provide further structural heterogeneity by adding additional sugars onto the O-antigen component of the lipopolysaccharide. Here we identify and examine the O-antigen modifying glucosyltransferase genes from the genomes of Salmonella enterica and Salmonella bongori serovars. We show that Salmonella generally carries between 1 and 4 gtr operons that we have classified into 10 families on the basis of gtrC sequence with apparent O-antigen modification detected for five of these families. The gtr operons localize to bacteriophage-associated genomic regions and exhibit a dynamic evolutionary history driven by recombination and gene shuffling events leading to new gene combinations. Furthermore, evidence of Dam- and OxyR-dependent phase variation of gtr gene expression was identified within eight gtr families. Thus, as O-antigen modification generates significant intra- and inter-strain phenotypic diversity, gtr-mediated modification is fundamental in assessing Salmonella strain variability. This will inform appropriate vaccine and diagnostic approaches, in addition to contributing to our understanding of host-pathogen interactions.     

Production of a Recombinant Peptide (Lasioglossin LL ΙΙΙ) and Assessment of Antibacterial and Antioxidant Activity

International Journal of Peptide Research and Therapeutics - The use of antimicrobial peptides (AMPs) as biopreservative to replace chemical preservatives has become of interest among consumers....     

The Prevalence of Compassion Fatigue and Burnout among Healthcare Professionals in Intensive Care Units: A Systematic Review

Background

Working in the stressful environment of the Intensive Care Unit (ICU) is an emotionally charged challenge that might affect the emotional stability of medical staff. The quality of care for ICU patients and their relatives might be threatened through long-term absenteeism or a brain and skill drain if the healthcare professionals leave their jobs prematurely in order to preserve their own health.

Purpose

The purpose of this review is to evaluate the literature related to emotional distress among healthcare professionals in the ICU, with an emphasis on the prevalence of burnout and compassion fatigue and the available preventive strategies.

Methods

A systematic literature review was conducted, using Embase, Medline OvidSP, Cinahl, Web-of-science, PsychINFO, PubMed publisher, Cochrane and Google Scholar for articles published between 1992 and June, 2014. Studies reporting the prevalence of burnout, compassion fatigue, secondary traumatic stress and vicarious trauma in ICU healthcare professionals were included, as well as related intervention studies.

Results

Forty of the 1623 identified publications, which included 14,770 respondents, met the selection criteria. Two studies reported the prevalence of compassion fatigue as 7.3% and 40%; five studies described the prevalence of secondary traumatic stress ranging from 0% to 38.5%. The reported prevalence of burnout in the ICU varied from 0% to 70.1%. A wide range of intervention strategies emerged from the recent literature search, such as different intensivist work schedules, educational programs on coping with emotional distress, improving communication skills, and relaxation methods.

Conclusions

The true prevalence of burnout, compassion fatigue, secondary traumatic stress and vicarious trauma in ICU healthcare professionals remains open for discussion. A thorough exploration of emotional distress in relation to communication skills, ethical rounds, and mindfulness might provide an appropriate starting point for the development of further preventive strategies.     

An Automated System for Skeletal Maturity Assessment by Extreme Learning Machines

Assessing skeletal age is a subjective and tedious examination process. Hence, automated assessment methods have been developed to replace manual evaluation in medical applications. In this study, a new fully automated method based on content-based image retrieval and using extreme learning machines (ELM) is designed and adapted to assess skeletal maturity. The main novelty of this approach is it overcomes the segmentation problem as suffered by existing systems. The estimation results of ELM models are compared with those of genetic programming (GP) and artificial neural networks (ANNs) models. The experimental results signify improvement in assessment accuracy over GP and ANN, while generalization capability is possible with the ELM approach. Moreover, the results are indicated that the ELM model developed can be used confidently in further work on formulating novel models of skeletal age assessment strategies. According to the experimental results, the new presented method has the capacity to learn many hundreds of times faster than traditional learning methods and it has sufficient overall performance in many aspects. It has conclusively been found that applying ELM is particularly promising as an alternative method for evaluating skeletal age.