68 research outputs found

    Sleep drive reconfigures wake-promoting clock circuitry to regulate adaptive behavior

    Get PDF
    Circadian rhythms help animals synchronize motivated behaviors to match environmental demands. Recent evidence indicates that clock neurons influence the timing of behavior by differentially altering the activity of a distributed network of downstream neurons. Downstream circuits can be remodeled by Hebbian plasticity, synaptic scaling, and, under some circumstances, activity-dependent addition of cell surface receptors; the role of this receptor respecification phenomena is not well studied. We demonstrate that high sleep pressure quickly reprograms the wake-promoting large ventrolateral clock neurons to express the pigment dispersing factor receptor (PDFR). The addition of this signaling input into the circuit is associated with increased waking and early mating success. The respecification of PDFR in both young and adult large ventrolateral neurons requires 2 dopamine (DA) receptors and activation of the transcriptional regulator nejire (cAMP response element-binding protein [CREBBP]). These data identify receptor respecification as an important mechanism to sculpt circuit function to match sleep levels with demand

    Intravenous versus epidural analgesia to reduce the incidence of gastrointestinal complications after elective pancreatoduodenectomy (the PAKMAN trial, DRKS 00007784): study protocol for a randomized controlled trial

    Get PDF
    Background: Despite substantial improvements in surgical and anesthesiological practices leading to decreased mortality of less than 5 % at high-volume centers, pancreatic surgery is still associated with high morbidity rates of up to 50 %. Attention is increasingly directed toward the optimization of perioperative management to reduce complications and enhance postoperative recovery. Currently, two different strategies for postoperative pain management after pancreatoduodenectomy are being routinely used: patient-controlled intravenous analgesia and thoracic epidural analgesia. Evidence is lacking to assess which strategy entails fewer postoperative complications. Methods/design: The PAKMAN trial is designed as an adaptive, pragmatic, randomized, controlled, multicenter, open-label, superiority trial with two parallel study groups. A total of 370 patients scheduled for elective pancreatoduodenectomy will be randomized after giving written informed consent, and 278 patients are needed for analysis. Patients with chronic pancreatitis, severe chronic obstructive pulmonary disease (COPD), American Society of Anesthesiologists (ASA) physical status classification ≄ IV, or chronic pain syndrome will be excluded. The group A intervention includes intraoperative general anesthesia and postoperative patient-controlled intravenous analgesia; the group B intervention comprises combined intraoperative general anesthesia and epidural analgesia with postoperative epidural analgesia. The primary endpoint of this trial is a composite of the gastrointestinal complications (delayed gastric emptying, pancreatic fistula, biliary leak, gastrointestinal bleeding, and postoperative ileus) up to postoperative day 30. The aim is to investigate whether the frequency of gastrointestinal complications following pancreatoduodenectomy can be reduced by 15 % using postoperative, patient-controlled intravenous analgesia compared with epidural analgesia. Discussion: Several previous studies investigating the two different strategies for postoperative pain management have mainly focused on their effectiveness in pain control. However, the PAKMAN trial is the first to compare them with regard to their impact on the surgical endpoint “postoperative gastrointestinal complications” after pancreatoduodenectomy. Trial registration: German Clinical Trials Register, DRKS0000778

    Sleep-promoting neurons remodel their response properties to calibrate sleep drive with environmental demands

    Get PDF
    Falling asleep at the wrong time can place an individual at risk of immediate physical harm. However, not sleeping degrades cognition and adaptive behavior. To understand how animals match sleep need with environmental demands, we used live-brain imaging to examine the physiological response properties of the dorsal fan-shaped body (dFB) following interventions that modify sleep (sleep deprivation, starvation, time-restricted feeding, memory consolidation) in Drosophila. We report that dFB neurons change their physiological response-properties to dopamine (DA) and allatostatin-A (AstA) in response to different types of waking. That is, dFB neurons are not simply passive components of a hard-wired circuit. Rather, the dFB neurons intrinsically regulate their response to the activity from upstream circuits. Finally, we show that the dFB appears to contain a memory trace of prior exposure to metabolic challenges induced by starvation or time-restricted feeding. Together, these data highlight that the sleep homeostat is plastic and suggests an underlying mechanism

    Benchmarking of Mutation Diagnostics in Clinical Lung Cancer Specimens

    Get PDF
    Treatment of EGFR-mutant non-small cell lung cancer patients with the tyrosine kinase inhibitors erlotinib or gefitinib results in high response rates and prolonged progression-free survival. Despite the development of sensitive mutation detection approaches, a thorough validation of these in a clinical setting has so far been lacking. We performed, in a clinical setting, a systematic validation of dideoxy ‘Sanger’ sequencing and pyrosequencing against massively parallel sequencing as one of the most sensitive mutation detection technologies available. Mutational annotation of clinical lung tumor samples revealed that of all patients with a confirmed response to EGFR inhibition, only massively parallel sequencing detected all relevant mutations. By contrast, dideoxy sequencing missed four responders and pyrosequencing missed two responders, indicating a dramatic lack of sensitivity of dideoxy sequencing, which is widely applied for this purpose. Furthermore, precise quantification of mutant alleles revealed a low correlation (r2 = 0.27) of histopathological estimates of tumor content and frequency of mutant alleles, thereby questioning the use of histopathology for stratification of specimens for individual analytical procedures. Our results suggest that enhanced analytical sensitivity is critically required to correctly identify patients responding to EGFR inhibition. More broadly, our results emphasize the need for thorough evaluation of all mutation detection approaches against massively parallel sequencing as a prerequisite for any clinical implementation

    The state of the art in the analysis of two-dimensional gel electrophoresis images

    Get PDF
    Software-based image analysis is a crucial step in the biological interpretation of two-dimensional gel electrophoresis experiments. Recent significant advances in image processing methods combined with powerful computing hardware have enabled the routine analysis of large experiments. We cover the process starting with the imaging of 2-D gels, quantitation of spots, creation of expression profiles to statistical expression analysis followed by the presentation of results. Challenges for analysis software as well as good practices are highlighted. We emphasize image warping and related methods that are able to overcome the difficulties that are due to varying migration positions of spots between gels. Spot detection, quantitation, normalization, and the creation of expression profiles are described in detail. The recent development of consensus spot patterns and complete expression profiles enables one to take full advantage of statistical methods for expression analysis that are well established for the analysis of DNA microarray experiments. We close with an overview of visualization and presentation methods (proteome maps) and current challenges in the field

    PLoS One

    Get PDF
    Age-related macular degeneration (AMD) is a common, progressive multifactorial vision-threatening disease and many genetic and environmental risk factors have been identified. The risk of AMD is influenced by lifestyle and diet, which may be reflected by an altered metabolic profile. Therefore, measurements of metabolites could identify biomarkers for AMD, and could aid in identifying high-risk individuals. Hypothesis-free technologies such as metabolomics have a great potential to uncover biomarkers or pathways that contribute to disease pathophysiology. To date, only a limited number of metabolomic studies have been performed in AMD. Here, we aim to contribute to the discovery of novel biomarkers and metabolic pathways for AMD using a targeted metabolomics approach of 188 metabolites. This study focuses on non-advanced AMD, since there is a need for biomarkers for the early stages of disease before severe visual loss has occurred. Targeted metabolomics was performed in 72 patients with early or intermediate AMD and 72 control individuals, and metabolites predictive for AMD were identified by a sparse partial least squares discriminant analysis. In our cohort, we identified four metabolite variables that were most predictive for early and intermediate stages of AMD. Increased glutamine and phosphatidylcholine diacyl C28:1 levels were detected in non-advanced AMD cases compared to controls, while the rate of glutaminolysis and the glutamine to glutamate ratio were reduced in non-advanced AMD. The association of glutamine with non-advanced AMD corroborates a recent report demonstrating an elevated glutamine level in early AMD using a different metabolomics technique. In conclusion, this study indicates that metabolomics is a suitable method for the discovery of biomarker candidates for AMD. In the future, larger metabolomics studies could add to the discovery of novel biomarkers in yet unknown AMD pathways and expand our insights in AMD pathophysiology

    Protocol for a randomised controlled trial to compare postoperative complications between minimally invasive and open DIStal PAnCreaTectomy (DISPACT-2 trial)

    No full text
    Introduction In recent years, minimally invasive distal pancreatectomy (MIDP) has been used with increasing frequency to accelerate patient recovery. Distal pancreatectomy has an overall morbidity rate of 30%–40%. The known advantages of minimally invasive techniques must be rigorously compared with those of open surgery before they can be completely implemented into clinical practice.Methods and analysis DISPACT-2 is a multicentre randomised controlled trial comparing minimally invasive (conventional laparoscopic or robotic assisted) with open distal pancreatic resection in patients undergoing elective surgery for benign as well as malign diseases of the pancreatic body and tail. After screening for eligibility and obtaining informed consent, a total of 294 adult patients will be preoperatively randomised in a 1:1 ratio. The primary hypothesis is that MIDP is non-inferior to open distal pancreatectomy in terms of postoperative mortality and morbidity expressed as the Comprehensive Complication Index (CCI) within 3 months after index operation, with a non-inferiority margin of 7.5 CCI points. Secondary endpoints include pancreas-specific complications, oncological safety and patient reported outcomes. Follow-up for each individual patient will be 2 years.Ethics and dissemination The DISPACT-2 trial has been approved by the Ethics Committee of the medical faculty of Heidelberg University (S-693/2017). Results of the primary endpoint will be available in 2024 and will be published at national and international meetings. Full results will be made available in an open access, peer-reviewed journal. The website www.dispact.de contains up-to-date information regarding the trial.Trial registration number DRKS0001401

    Conventional partial pancreatoduodenectomy versus an extended pancreatoduodenectomy (triangle operation) for pancreatic head cancers—study protocol for the randomised controlled TRIANGLE trial

    No full text
    Abstract Background Pancreatic ductal carcinoma (PDAC) is the fourth most frequent cause of cancer-related death in the Western world, and its incidence is rising. In patients that undergo curative resection, local recurrence (LR) is frequent. A recently described surgical technique of extended pancreatoduodenectomy (PD) termed the TRIANGLE operation has been proposed as a promising approach to reduce LR and improve disease-free survival in PDAC patients. Methods The TRIANGLE trial is a multicentre confirmatory randomised controlled superiority trial with two parallel study groups. A total of 270 patients with suspected or histologically confirmed pancreatic head cancer scheduled for PD will be included in the trial and randomly assigned to the intervention group (extended PD defined as Inoue level 3 dissection along the superior mesenteric and celiac artery as well as removal of all soft tissue in the so-called triangle between the celiac artery, the SMA and the mesenterico-portal axis) or the control group (conventional PD with lymphadenectomy and removal of soft tissue according to current guidelines). The primary endpoint of the trial will be the disease-free survival of patients. Other perioperative outcomes as well as oncological parameters and patient-reported outcomes will be analysed as secondary outcomes. Discussion Despite multimodal treatment, LR remains high and disease-free survival is limited following PD for PDAC. The TRIANGLE operation could address these shortcomings of conventional PD as indicated in several retrospective studies. However, this technique could be associated with more adverse events for patients including intractable diarrhoea. The TRIANGLE trial will close the evidence gap as well as offer a risk-benefit assessment of this more radical approach to PD. Trial registration German Clinical Trials Register DRKS00030576 (UTN U1111-1243-4412) 19th December 2022
    • 

    corecore