257 research outputs found

    Novel self-assembled morphologies from isotropic interactions

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    We present results from particle simulations with isotropic medium range interactions in two dimensions. At low temperature novel types of aggregated structures appear. We show that these structures can be explained by spontaneous symmetry breaking in analytic solutions to an adaptation of the spherical spin model. We predict the critical particle number where the symmetry breaking occurs and show that the resulting phase diagram agrees well with results from particle simulations.Comment: 4 pages, 4 figure

    Normal neonatal TREC and KREC levels in early onset juvenile idiopathic arthritis

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    Objective: Dysregulated central tolerance predisposes to autoimmune diseases. Reduced thymic output as well as compromised central B cell tolerance checkpoints have been proposed in the pathogenesis of juvenile idiopathic arthritis (JIA). The aim of this study was to investigate neonatal levels of T-cell receptor excision circles (TRECs) and kappa-deleting element excision circles (KRECs), as markers of T- and B-cell output at birth, in patients with early onset JIA. Methods: TRECs and KRECs were quantitated by multiplex qPCR from dried blood spots (DBS), collected 2–5 days after birth, in 156 children with early onset JIA and in 312 matched controls. Results: When analysed from neonatal dried blood spots, the median TREC level was 78 (IQR 55–113) in JIA cases and 88 (IQR 57–117) copies/well in controls. The median KREC level was 51 (IQR 35–69) and 53 (IQR 35–74) copies/well, in JIA cases and controls, respectively. Stratification by sex and age at disease onset did not reveal any difference in the levels of TRECs and KRECs. Conclusion: T- and B-cell output at birth, as measured by TREC and KREC levels in neonatal dried blood spots, does not differ in children with early onset JIA compared to controls

    Identification of aberrant forms of alkaline sphingomyelinase (NPP7) associated with human liver tumorigenesis

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    Alkaline sphingomyelinase (alk-SMase) is expressed in the intestine and human liver. It may inhibit colonic tumorigenesis, and loss of function mutations have been identified in human colon cancer. The present study investigates its expression in human liver cancer. In HepG2 liver cancer cells, RT–PCR identified three transcripts with 1.4, 1.2 and 0.4 kb, respectively. The 1.4 kb form is the wild-type cDNA with five translated exons, the 1.2 kb product lacks exon 4 and the 0.4 kb form is a combination of exons 1 and 5. Genomic sequence showed that these aberrant transcripts were products of alternative splicing. Transient expression of the 1.2 kb form showed no alk-SMase activity. In HepG2 cells, the alk-SMase activity is low in monolayer condition and increased with cell polarisation. Coexistence of 1.4 and 1.2 kb forms was also identified in one hepatoma biopsy. GenBank search identified a cDNA clone from human liver tumour, which codes a protein containing full length of alk-SMase plus a 73-amino-acid tag at the N terminus. The aberrant form was translated by an alternative starting codon upstream of the wild-type mRNA. Expression study showed that linking the tag markedly reduced the enzyme activity. We also analysed human liver biopsy samples and found relatively low alk-SMase activity in diseases with increased risk of liver tumorigenesis. In conclusion, expression of alk-SMase is changed in hepatic tumorigenesis, resulting in loss or marked reduction of the enzyme function

    Fluorescent N-arylaminonaphthalene sulfonate probes for amyloid aggregation of α-synuclein.

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    The deposition of fibrillar structures (amyloids) is characteristic of pathological conditions including Alzheimer's and Parkinson's diseases. The detection of protein deposits and the evaluation of their kinetics of aggregation are generally based on fluorescent probes such as thioflavin T and Congo red. In a search for improved fluorescence tools for studying amyloid formation, we explored the ability of N-arylaminonaphthalene sulfonate (NAS) derivatives to act as noncovalent probes of α-synuclein (AS) fibrillation, a process linked to Parkinson's disease and other neurodegenerative disorders. The compounds bound to fibrillar AS with micromolar K(d)s, and exhibited fluorescence enhancement, hyperchromism, and high anisotropy. We conclude that the probes experience a hydrophobic environment and/or restricted motion in a polar region. Time- and spectrally resolved emission intensity and anisotropy provided further information regarding structural features of the protein and the dynamics of solvent relaxation. The steady-state and time-resolved parameters changed during the course of aggregation. Compared with thioflavin T, NAS derivatives constitute more sensitive and versatile probes for AS aggregation, and in the case of bis-NAS detect oligomeric as well as fibrillar species. They can function in convenient, continuous assays, thereby providing useful tools for studying the mechanisms of amyloid formation and for high-throughput screening of factors inhibiting and/or reversing protein aggregation in neurodegenerative diseases

    Women's experience of intrapartum transfer from a Western Australian birth centre co-located to a tertiary maternity hospital

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    © 2016 Kuliukas et al. Background: The aim of this Western Australian study was to describe the overall labour and birth experience of women who were transferred during the first and second stages of labour from a low risk woman-centred, midwifery-led birth centre to a co-located tertiary maternity referral hospital. Methods: Using a descriptive phenomenological design, fifteen women were interviewed up to 8weeks post birth (July to October, 2013) to explore their experience of the intrapartum transfer. Giorgi's method of analysis was used. Results: The following themes and subthemes emerged: 1) The midwife's voice with subthemes, a) The calming effect and b) Speaking up on my behalf; 2) In the zone with subthemes, a) Hanging in there and b) Post birth rationalizing; 3) Best of both worlds with subthemes a) The feeling of relief on transfer to tertiary birth suite and b) Returning back to the comfort and familiarity of the birth centre; 4) Lost sense of self; and 5) Lost birth dream with subthemes a) Narrowing of options and b) Feeling of panic. Women found the midwife's voice guided them through the transfer experience and were appreciative of continuity of care. There was a sense of disruption to expectations and disappointment in not achieving the labour and birth they had anticipated. There was however appreciation that the referral facility was nearby and experts were close at hand. The focus of care altered from woman to fetus, making women feel diminished. Women were glad to return to the familiar birth centre after the birth with the opportunity to talk through and fully understand their labour journey which helped them contextualise the transfer as one part of the whole experience. Conclusions: Findings can inform midwives of the value of a continuity of care model within a birth centre, allowing women both familiarity and peace of mind. Maternity care providers should ensure that the woman remains the focus of care after transfer and understand the significance of effective communication to ensure women are included in all care discussions

    Methylated BSA Mimics Amyloid-Related Proteins and Triggers Inflammation

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    The mechanistic study of inflammatory or autoimmune diseases requires the generation of mouse models that reproduce the alterations in immune responses observed in patients. Methylated bovine serum albumin (mBSA) has been widely used to induce antigen-specific inflammation in targeted organs or in combination with single stranded DNA (ssDNA) to generate anti-nucleic acids antibodies in vivo. However, the mechanism by which this modified protein triggers inflammation is poorly understood. By analyzing the biochemical properties of mBSA, we found that mBSA exhibits features of an intermediate of protein misfolding pathway. mBSA readily interact with a list of dyes that have binding specificity towards amyloid fibrils. Intriguingly, mBSA displayed cytotoxic activity and its binding to ssDNA further enhanced formation of beta-sheet rich amyloid fibrils. Moreover, mBSA is recognized by the serum amyloid P, a protein unanimously associated with amyloid plaques in vivo. In macrophages, we observed that mBSA disrupted the lysosomal compartment, signaled along the NLRP3 inflammasome pathway, and activated caspase 1, which led to the production of IL-1β. In vivo, mBSA triggered rapid and prominent immune cell infiltration that is dependent on IL-1β induction. Taken together, these data demonstrate that by mimicking amyloidogenic proteins mBSA exhibits strong innate immune functions and serves as a potent adjuvant. These findings advance our understanding on the underlying mechanism of how aberrant immune responses lead to autoimmune reactions

    Risk perception after genetic counseling in patients with increased risk of cancer

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    <p>Abstract</p> <p>Background</p> <p>Counselees are more aware of genetics and seek information, reassurance, screening and genetic testing. Risk counseling is a key component of genetic counseling process helping patients to achieve a realistic view for their own personal risk and therefore adapt to the medical, psychological and familial implications of disease and to encourage the patient to make informed choices <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr></abbrgrp>.</p> <p>The aim of this study was to conceptualize risk perception and anxiety about cancer in individuals attending to genetic counseling.</p> <p>Methods</p> <p>The questionnaire study measured risk perception and anxiety about cancer at three time points: before and one week after initial genetic counseling and one year after completed genetic investigations. Eligibility criteria were designed to include only index patients without a previous genetic consultation in the family. A total of 215 individuals were included. Data was collected during three years period.</p> <p>Results</p> <p>Before genetic counseling all of the unaffected participants subjectively estimated their risk as higher than their objective risk. Participants with a similar risk as the population overestimated their risk most. All risk groups estimated the risk for children's/siblings to be lower than their own. The benefits of preventive surveillance program were well understood among unaffected participants.</p> <p>The difference in subjective risk perception before and directly after genetic counseling was statistically significantly lower in all risk groups. Difference in risk perception for children as well as for population was also statistically significant. Experienced anxiety about developing cancer in the unaffected subjects was lower after genetic counseling compared to baseline in all groups. Anxiety about cancer had clear correlation to perceived risk of cancer before and one year after genetic investigations.</p> <p>The affected participants overestimated their children's risk as well as risk for anyone in population. Difference in risk perception for children/siblings as for the general population was significant between the first and second measurement time points. Anxiety about developing cancer again among affected participants continued to be high throughout this investigation.</p> <p>Conclusion</p> <p>The participant's accuracy in risk perception was poor, especially in low risk individuals before genetic counseling. There was a general trend towards more accurate estimation in all risk groups after genetic counseling. The importance of preventive programs was well understood. Cancer anxiety was prevalent and associated with risk perception, but decreased after genetic counseling.</p> <p><abbrgrp><abbr bid="B1">1</abbr></abbrgrp> National Society of Genetic Counselors (2005), Genetic Counseling as a Profession. Available at <url>http://www.nsgc.org/about/definition.cfm</url> (accessed November 25th 2007)</p> <p><abbrgrp><abbr bid="B2">2</abbr></abbrgrp> Julian-Reynier C., Welkenhuysen M-, Hagoel L., Decruyenaere M., Hopwood P. (2003) Risk communication strategies: state of the art and effectiveness in the context of cancer genetic services. Eur J of Human Genetics 11, 725736.</p

    Pregnancy related anxiety and general anxious or depressed mood and the choice for birth setting:A secondary data-analysis of the DELIVER study

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    BACKGROUND: In several developed countries women with a low risk of complications during pregnancy and childbirth can make choices regarding place of birth. In the Netherlands, these women receive midwife-led care and can choose between a home or hospital birth. The declining rate of midwife-led home births alongside the recent debate on safety of home births in the Netherlands, however, suggest an association of choice of birth place with psychological factors related to safety and risk perception. In this study associations of pregnancy related anxiety and general anxious or depressed mood with (changes in) planned place of birth were explored in low risk women in midwife-led care until the start of labour. METHODS: Data (n = 2854 low risk women in midwife-led care at the onset of labour) were selected from the prospective multicenter DELIVER study. Women completed the Pregnancy Related Anxiety Questionnaire-Revised (PRAQ-R) to assess pregnancy related anxiety and the EuroQol-6D (EQ-6D) for an anxious and/or depressed mood. RESULTS: A high PRAQ-R score was associated with planned hospital birth in nulliparous (aOR 1.92; 95% CI 1.32–2.81) and parous women (aOR 2.08; 95% CI 1.55–2.80). An anxious or depressed mood was associated with planned hospital birth (aOR 1.58; 95% CI 1.20–2.08) and with being undecided (aOR 1.99; 95% CI 1.23–2.99) in parous women only. The majority of women did not change their planned place of birth. Changing from an initially planned home birth to a hospital birth later in pregnancy was, however, associated with becoming anxious or depressed after 35 weeks gestation in nulliparous women (aOR 4.17; 95% CI 1.35–12.89) and with pregnancy related anxiety at 20 weeks gestation in parous women (aOR 3.91; 95% CI 1.32–11.61). CONCLUSION: Low risk women who planned hospital birth (or who were undecided) more often reported pregnancy related anxiety or an anxious or depressed mood. Women who changed from home to hospital birth during pregnancy more often reported pregnancy related anxiety or an anxious or depressed mood in late pregnancy. Anxiety should be adequately addressed in the process of informed decision-making regarding planned place of birth in low risk women
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