65 research outputs found

    Distinctive expression patterns of 185/333 genes in the purple sea urchin, Strongylocentrotus purpuratus: an unexpectedly diverse family of transcripts in response to LPS, β-1,3-glucan, and dsRNA

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    BACKGROUND: A diverse set of transcripts called 185/333 is strongly expressed in sea urchins responding to immune challenge. Optimal alignments of full-length 185/333 cDNAs requires the insertion of large gaps that define 25 blocks of sequence called elements. The presence or absence of individual elements also defines a specific element pattern for each message. Individual sea urchins were challenged with pathogen associated molecular patterns (PAMPs) (lipopolysaccharide, β-1,3-glucan, or double stranded RNA), and changes in the 185/333 message repertoire were followed over time. RESULTS: Each animal expressed a diverse set of 185/333 messages prior to challenge and a 0.96 kb message was the predominant size after challenge. Sequence analysis of the cloned messages indicated that the major element pattern expressed in immunoquiescent sea urchins was either C1 or E2.1. In contrast, most animals responding to lipopolysaccharide, β-1,3-glucan or injury, predominantly expressed messages of the E2 pattern. In addition to the major patterns, extensive element pattern diversity was observed among the different animals before and after challenge. Nucleotide sequence diversity of the transcripts increased in response to β-1,3-glucan, double stranded RNA and injury, whereas diversity decreased in response to LPS. CONCLUSION: These results illustrate that sea urchins appear to be able to differentiate among different PAMPs by inducing the transcription of different sets of 185/333 genes. Furthermore, animals may share a suite of 185/333 genes that are expressed in response to common pathogens, while also maintaining a large number of unique genes within the population

    Pathologic gene network rewiring implicates PPP1R3A as a central regulator in pressure overload heart failure

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    Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvest 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtain genome-wide genotyping and gene expression measurements for a subset of 313. We build failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs). PPP1R3A emerges as a regulator whose network connectivity changes significantly between health and disease. RNA sequencing after PPP1R3A knockdown validates network-based predictions, and highlights metabolic pathway regulation associated with increased cardiomyocyte size and perturbed respiratory metabolism. Mice lacking PPP1R3A are protected against pressure-overload heart failure. We present a global gene interaction map of the human heart failure transition, identify previously unreported cardiac eQTLs, and demonstrate the discovery potential of disease-specific networks through the description of PPP1R3A as a central regulator in heart failure

    Investigating light sensitivity in bipolar disorder (HELIOS-BD)

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    Many people with bipolar disorder have disrupted circadian rhythms. This means that the timing of sleep and wake activities becomes out-of-sync with the standard 24-hour cycle. Circadian rhythms are strongly influenced by light levels and previous research suggests that people with bipolar disorder might have a heightened sensitivity to light, causing more circadian rhythm disruption, increasing the potential for triggering a mood switch into mania or depression. Lithium has been in clinical use for over 70 years and is acknowledged to be the most effective long-term treatment for bipolar disorder. Lithium has many reported actions in the body but the precise mechanism of action in bipolar disorder remains an active area of research. Central to this project is recent evidence that lithium may work by stabilising circadian rhythms of mood, cognition and rest/activity. Our primary hypothesis is that people with bipolar disorder have some pathophysiological change at the level of the retina which makes them hypersensitive to the visual and non-visual effects of light, and therefore more susceptible to circadian rhythm dysfunction. We additionally hypothesise that the mood-stabilising medication lithium is effective in bipolar disorder because it reduces this hypersensitivity, making individuals less vulnerable to light-induced circadian disruption. We will recruit 180 participants into the HELIOS-BD study. Over an 18-month period, we will assess visual and non-visual responses to light, as well as retinal microstructure, in people with bipolar disorder compared to healthy controls. Further, we will assess whether individuals with bipolar disorder who are being treated with lithium have less pronounced light responses and attenuated retinal changes compared to individuals with bipolar disorder not being treated with lithium. This study represents a comprehensive investigation of visual and non-visual light responses in a large bipolar disorder population, with great translational potential for patient stratification and treatment innovation.</p

    Random field sampling for a simplified model of melt-blowing considering turbulent velocity fluctuations

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    In melt-blowing very thin liquid fiber jets are spun due to high-velocity air streams. In literature there is a clear, unsolved discrepancy between the measured and computed jet attenuation. In this paper we will verify numerically that the turbulent velocity fluctuations causing a random aerodynamic drag on the fiber jets -- that has been neglected so far -- are the crucial effect to close this gap. For this purpose, we model the velocity fluctuations as vector Gaussian random fields on top of a k-epsilon turbulence description and develop an efficient sampling procedure. Taking advantage of the special covariance structure the effort of the sampling is linear in the discretization and makes the realization possible

    A Novel Task for the Investigation of Action Acquisition

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    We present a behavioural task designed for the investigation of how novel instrumental actions are discovered and learnt. The task consists of free movement with a manipulandum, during which the full range of possible movements can be explored by the participant and recorded. A subset of these movements, the ‘target’, is set to trigger a reinforcing signal. The task is to discover what movements of the manipulandum evoke the reinforcement signal. Targets can be defined in spatial, temporal, or kinematic terms, can be a combination of these aspects, or can represent the concatenation of actions into a larger gesture. The task allows the study of how the specific elements of behaviour which cause the reinforcing signal are identified, refined and stored by the participant. The task provides a paradigm where the exploratory motive drives learning and as such we view it as in the tradition of Thorndike [1]. Most importantly it allows for repeated measures, since when a novel action is acquired the criterion for triggering reinforcement can be changed requiring a new action to be discovered. Here, we present data using both humans and rats as subjects, showing that our task is easily scalable in difficulty, adaptable across species, and produces a rich set of behavioural measures offering new and valuable insight into the action learning process

    Specific ion channels contribute to key elements of pathology during secondary degeneration following neurotrauma

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    Background: Following partial injury to the central nervous system, cells beyond the initial injury site undergo secondary degeneration, exacerbating loss of neurons, compact myelin and function. Changes in Ca 2+ flux are associated with metabolic and structural changes, but it is not yet clear how flux through specific ion channels contributes to the various pathologies. Here, partial optic nerve transection in adult female rats was used to model secondary degeneration. Treatment with combinations of three ion channel inhibitors was used as a tool to investigate which elements of oxidative and structural damage related to long term functional outcomes. The inhibitors employed were the voltage gated Ca 2+ channel inhibitor Lomerizine (Lom), the Ca 2+ permeable AMPA receptor inhibitor YM872 and the P2X 7 receptor inhibitor oxATP. Results: Following partial optic nerve transection, hyper-phosphorylation of Tau and acetylated tubulin immunoreactivity were increased, and Nogo-A immunoreactivity was decreased, indicating that axonal changes occurred acutely. All combinations of ion channel inhibitors reduced hyper-phosphorylation of Tau and increased Nogo-A immunoreactivity at day 3 after injury. However, only Lom/oxATP or all three inhibitors in combination significantly reduced acetylated tubulin immunoreactivity. Most combinations of ion channel inhibitors were effective in restoring the lengths of the paranode and the paranodal gap, indicative of the length of the node of Ranvier, following injury. However, only all three inhibitors in combination restored to normal Ankyrin G length at the node of Ranvier. Similarly, HNE immunoreactivity and loss of oligodendrocyte precursor cells were only limited by treatment with all three ion channel inhibitors in combination. Conclusions: Data indicate that inhibiting any of a range of ion channels preserves certain elements of axon and node structure and limits some oxidative damage following injury, whereas ionic flux through all three channels must be inhibited to prevent lipid peroxidation and preserve Ankyrin G distribution and OPCs

    A highly specific and sensitive serological assay detects SARS‑CoV‑2 antibody levels in COVID‑19 patients that correlate with neutralization

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    Objective The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic challenges national health systems and the global economy. Monitoring of infection rates and seroprevalence can guide public health measures to combat the pandemic. This depends on reliable tests on active and former infections. Here, we set out to develop and validate a specific and sensitive enzyme linked immunosorbent assay (ELISA) for detection of anti SARS-CoV-2 antibody levels. Methods In our ELISA, we used SARS-CoV-2 receptor-binding domain (RBD) and a stabilized version of the spike (S) ectodomain as antigens. We assessed sera from patients infected with seasonal coronaviruses, SARS-CoV-2 and controls. We determined and monitored IgM-, IgA- and IgG-antibody responses towards these antigens. In addition, for a panel of 22 sera, virus neutralization and ELISA parameters were measured and correlated. Results The RBD-based ELISA detected SARS-CoV-2-directed antibodies, did not cross-react with seasonal coronavirus antibodies and correlated with virus neutralization (R2 = 0.89). Seroconversion started at 5 days after symptom onset and led to robust antibody levels at 10 days after symptom onset. We demonstrate high specificity (99.3%; N = 1000) and sensitivity (92% for IgA, 96% for IgG and 98% for IgM; > 10 days after PCR-proven infection; N = 53) in serum. Conclusions With the described RBD-based ELISA protocol, we provide a reliable test for seroepidemiological surveys. Due to high specificity and strong correlation with virus neutralization, the RBD ELISA holds great potential to become a preferred tool to assess thresholds of protective immunity after infection and vaccination

    New Australian guidelines for the treatment of alcohol problems: an overview of recommendations

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    Summary of recommendations and levels of evidence Chapter 2: Screening and assessment for unhealthy alcohol use Screening Screening for unhealthy alcohol use and appropriate interventions should be implemented in general practice (Level A), hospitals (Level B), emergency departments and community health and welfare settings (Level C). Quantity–frequency measures can detect consumption that exceeds levels in the current Australian guidelines (Level B). The Alcohol Use Disorders Identification Test (AUDIT) is the most effective screening tool and is recommended for use in primary care and hospital settings. For screening in the general community, the AUDIT-C is a suitable alternative (Level A). Indirect biological markers should be used as an adjunct to screening (Level A), and direct measures of alcohol in breath and/or blood can be useful markers of recent use (Level B). Assessment Assessment should include evaluation of alcohol use and its effects, physical examination, clinical investigations and collateral history taking (Level C). Assessment for alcohol-related physical problems, mental health problems and social support should be undertaken routinely (GPP). Where there are concerns regarding the safety of the patient or others, specialist consultation is recommended (Level C). Assessment should lead to a clear, mutually acceptable treatment plan which specifies interventions to meet the patient’s needs (Level D). Sustained abstinence is the optimal outcome for most patients with alcohol dependence (Level C). Chapter 3: Caring for and managing patients with alcohol problems: interventions, treatments, relapse prevention, aftercare, and long term follow-up Brief interventions Brief motivational interviewing interventions are more effective than no treatment for people who consume alcohol at risky levels (Level A). Their effectiveness compared with standard care or alternative psychosocial interventions varies by treatment setting. They are most effective in primary care settings (Level A). Psychosocial interventions Cognitive behaviour therapy should be a first-line psychosocial intervention for alcohol dependence. Its clinical benefit is enhanced when it is combined with pharmacotherapy for alcohol dependence or an additional psychosocial intervention (eg, motivational interviewing) (Level A). Motivational interviewing is effective in the short term and in patients with less severe alcohol dependence (Level A). Residential rehabilitation may be of benefit to patients who have moderate-to-severe alcohol dependence and require a structured residential treatment setting (Level D). Alcohol withdrawal management Most cases of withdrawal can be managed in an ambulatory setting with appropriate support (Level B). Tapering diazepam regimens (Level A) with daily staged supply from a pharmacy or clinic are recommended (GPP). Pharmacotherapies for alcohol dependence Acamprosate is recommended to help maintain abstinence from alcohol (Level A). Naltrexone is recommended for prevention of relapse to heavy drinking (Level A). Disulfiram is only recommended in close supervision settings where patients are motivated for abstinence (Level A). Some evidence for off-label therapies baclofen and topiramate exists, but their side effect profiles are complex and neither should be a first-line medication (Level B). Peer support programs Peer-led support programs such as Alcoholics Anonymous and SMART Recovery are effective at maintaining abstinence or reductions in drinking (Level A). Relapse prevention, aftercare and long-term follow-up Return to problematic drinking is common and aftercare should focus on addressing factors that contribute to relapse (GPP). A harm-minimisation approach should be considered for patients who are unable to reduce their drinking (GPP). Chapter 4: Providing appropriate treatment and care to people with alcohol problems: a summary for key specific populations Gender-specific issues Screen women and men for domestic abuse (Level C). Consider child protection assessments for caregivers with alcohol use disorder (GPP). Explore contraceptive options with women of reproductive age who regularly consume alcohol (Level B). Pregnant and breastfeeding women Advise pregnant and breastfeeding women that there is no safe level of alcohol consumption (Level B). Pregnant women who are alcohol dependent should be admitted to hospital for treatment in an appropriate maternity unit that has an addiction specialist (GPP). Young people Perform a comprehensive HEEADSSS assessment for young people with alcohol problems (Level B). Treatment should focus on tangible benefits of reducing drinking through psychotherapy and engagement of family and peer networks (Level B). Aboriginal and Torres Strait Islander peoples Collaborate with Aboriginal or Torres Strait Islander health workers, organisations and communities, and seek guidance on patient engagement approaches (GPP). Use validated screening tools and consider integrated mainstream and Aboriginal or Torres Strait Islander-specific approaches to care (Level B). Culturally and linguistically diverse groups Use an appropriate method, such as the “teach-back” technique, to assess the need for language and health literacy support (Level C). Engage with culture-specific agencies as this can improve treatment access and success (Level C). Sexually diverse and gender diverse populations Be mindful that sexually diverse and gender diverse populations experience lower levels of satisfaction, connection and treatment completion (Level C). Seek to incorporate LGBTQ-specific treatment and agencies (Level C). Older people All new patients aged over 50 years should be screened for harmful alcohol use (Level D). Consider alcohol as a possible cause for older patients presenting with unexplained physical or psychological symptoms (Level D). Consider shorter acting benzodiazepines for withdrawal management (Level D). Cognitive impairment Cognitive impairment may impair engagement with treatment (Level A). Perform cognitive screening for patients who have alcohol problems and refer them for neuropsychological assessment if significant impairment is suspected (Level A). Summary of key recommendations and levels of evidence Chapter 5: Understanding and managing comorbidities for people with alcohol problems: polydrug use and dependence, co-occurring mental disorders, and physical comorbidities Polydrug use and dependence Active alcohol use disorder, including dependence, significantly increases the risk of overdose associated with the administration of opioid drugs. Specialist advice is recommended before treatment of people dependent on both alcohol and opioid drugs (GPP). Older patients requiring management of alcohol withdrawal should have their use of pharmaceutical medications reviewed, given the prevalence of polypharmacy in this age group (GPP). Smoking cessation can be undertaken in patients with alcohol dependence and/or polydrug use problems; some evidence suggests varenicline may help support reduction of both tobacco and alcohol consumption (Level C). Co-occurring mental disorders More intensive interventions are needed for people with comorbid conditions, as this population tends to have more severe problems and carries a worse prognosis than those with single pathology (GPP). The Kessler Psychological Distress Scale (K10 or K6) is recommended for screening for comorbid mental disorders in people presenting for alcohol use disorders (Level A). People with alcohol use disorder and comorbid mental disorders should be offered treatment for both disorders; care should be taken to coordinate intervention (Level C). Physical comorbidities Patients should be advised that alcohol use has no beneficial health effects. There is no clear risk-free threshold for alcohol intake. The safe dose for alcohol intake is dependent on many factors such as underlying liver disease, comorbidities, age and sex (Level A). In patients with alcohol use disorder, early recognition of the risk for liver cirrhosis is critical. Patients with cirrhosis should abstain from alcohol and should be offered referral to a hepatologist for liver disease management and to an addiction physician for management of alcohol use disorder (Level A). Alcohol abstinence reduces the risk of cancer and improves outcomes after a diagnosis of cancer (Level A)
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