Modulation by Neuropeptides with Overlapping Targets Results in Functional Overlap in Oscillatory Circuit Activation.

Neuromodulation lends flexibility to neural circuit operation but the general notion that different neuromodulators sculpt neural circuit activity into distinct and characteristic patterns is complicated by interindividual variability. In addition, some neuromodulators converge onto the same signaling pathways, with similar effects on neurons and synapses. We compared the effects of three neuropeptides on the rhythmic pyloric circuit in the stomatogastric ganglion of male crabs, Cancer borealis Proctolin (PROC), crustacean cardioactive peptide (CCAP), and red pigment concentrating hormone (RPCH) activate the same modulatory inward current, I MI, and have convergent actions on synapses. However, while PROC targets all four neuron types in the core pyloric circuit, CCAP and RPCH target the same subset of only two neurons. After removal of spontaneous neuromodulator release, none of the neuropeptides restored the control cycle frequency, but all restored the relative timing between neuron types. Consequently, differences between neuropeptide effects were mainly found in the spiking activity of different neuron types. We performed statistical comparisons using the Euclidean distance in the multidimensional space of normalized output attributes to obtain a single measure of difference between modulatory states. Across preparations, the circuit output in PROC was distinguishable from CCAP and RPCH, but CCAP and RPCH were not distinguishable from each other. However, we argue that even between PROC and the other two neuropeptides, population data overlapped enough to prevent reliable identification of individual output patterns as characteristic for a specific neuropeptide. We confirmed this notion by showing that blind classifications by machine learning algorithms were only moderately successful.Significance Statement It is commonly assumed that distinct behaviors or circuit activities can be elicited by different neuromodulators. Yet it is unknown to what extent these characteristic actions remain distinct across individuals. We use a well-studied circuit model of neuromodulation to examine the effects of three neuropeptides, each known to produce a distinct activity pattern in controlled studies. We find that, when compared across individuals, the three peptides elicit activity patterns that are either statistically indistinguishable or show too much overlap to be labeled characteristic. We ascribe this to interindividual variability and overlapping subcellular actions of the modulators. Because both factors are common in all neural circuits, these findings have broad significance for understanding chemical neuromodulatory actions while considering interindividual variability.

Structures, functions and adaptations of the human LINE-1 ORF2 protein.

The LINE-1 (L1) retrotransposon is an ancient genetic parasite that has written around one-third of the human genome through a 'copy and paste' mechanism catalysed by its multifunctional enzyme, open reading frame 2 protein (ORF2p)1. ORF2p reverse transcriptase (RT) and endonuclease activities have been implicated in the pathophysiology of cancer2,3, autoimmunity4,5 and ageing6,7, making ORF2p a potential therapeutic target. However, a lack of structural and mechanistic knowledge has hampered efforts to rationally exploit it. We report structures of the human ORF2p 'core' (residues 238-1061, including the RT domain) by X-ray crystallography and cryo-electron microscopy in several conformational states. Our analyses identified two previously undescribed folded domains, extensive contacts to RNA templates and associated adaptations that contribute to unique aspects of the L1 replication cycle. Computed integrative structural models of full-length ORF2p show a dynamic closed-ring conformation that appears to open during retrotransposition. We characterize ORF2p RT inhibition and reveal its underlying structural basis. Imaging and biochemistry show that non-canonical cytosolic ORF2p RT activity can produce RNA:DNA hybrids, activating innate immune signalling through cGAS/STING and resulting in interferon production6-8. In contrast to retroviral RTs, L1 RT is efficiently primed by short RNAs and hairpins, which probably explains cytosolic priming. Other biochemical activities including processivity, DNA-directed polymerization, non-templated base addition and template switching together allow us to propose a revised L1 insertion model. Finally, our evolutionary analysis demonstrates structural conservation between ORF2p and other RNA- and DNA-dependent polymerases. We therefore provide key mechanistic insights into L1 polymerization and insertion, shed light on the evolutionary history of L1 and enable rational drug development targeting L1.

Intravesical Ty21a treatment of non-muscle invasive bladder cancer induces immune responses that correlate with safety and may be associated to therapy potential.

BACKGROUND: Standard of care treatment of non-muscle invasive bladder cancer (NMIBC) with intravesical Bacillus Calmette Guérin (BCG) is associated with side effects, disease recurrence/progression and supply shortages. We recently showed in a phase I trial (NCT03421236) that intravesical instillation in patients with NMIBC with the maximal tolerated dose of Ty21a/Vivotif, the oral vaccine against typhoid fever, might have a better safety profile. In the present report, we assessed the immunogenicity of intravesical Ty21a in patients of the clinical trial that had received the maximal tolerated dose and compared it with data obtained in patients that had received standard BCG. METHODS: Urinary cytokines and immune cells of patients with NMIBC treated with intravesical instillations of Ty21a (n=13, groups A and F in NCT03421236) or with standard BCG in a concomitant observational study (n=12, UROV1) were determined by Luminex and flow cytometry, respectively. Serum anti-lipopolysaccharide Typhi antibodies and circulating Ty21a-specific T-cell responses were also determined in the Ty21a patients. Multiple comparisons of different paired variables were performed with a mixed-effect analysis, followed by Sidak post-test. Single comparisons were performed with a paired or an unpaired Student's t-test. RESULTS: As compared with BCG, Ty21a induced lower levels of inflammatory urinary cytokines, which correlated to the milder adverse events (AEs) observed in Ty21a patients. However, both Ty21a and BCG induced a Th1 tumor environment. Peripheral Ty21a-specific T-cell responses and/or antibodies were observed in most Ty21a patients, pointing the bladder as an efficient local immune inductive site. Besides, Ty21a-mediated stimulation of unconventional Vδ2 T cells was also observed, which turned out more efficient than BCG. Finally, few Ty21a instillations were sufficient for increasing urinary infiltration of dendritic cells and T cells, which were previously associated with therapeutic efficacy in the orthotopic mouse model of NMIBC. CONCLUSIONS: Ty21a immunotherapy of patient with NMIBC is promising with fewer inflammatory cytokines and mild AE, but induction of immune responses with possible antitumor potentials. Future phase II clinical trials are necessary to explore possible efficacy of intravesical Ty21a.

Role of Hydrogen Sulfide in Inflammatory Bowel Disease.

Hydrogen sulfide (H2S), originally known as toxic gas, has now attracted attention as one of the gasotransmitters involved in many reactions in the human body. H2S has been assumed to play a role in the pathogenesis of many chronic diseases, of which the exact pathogenesis remains unknown. One of them is inflammatory bowel disease (IBD), a chronic intestinal disease subclassified as Crohn's disease (CD) and ulcerative colitis (UC). Any change in the amount of H2S seems to be linked to inflammation in this illness. These changes can be brought about by alterations in the microbiota, in the endogenous metabolism of H2S and in the diet. As both too little and too much H2S drive inflammation, a balanced level is needed for intestinal health. The aim of this review is to summarize the available literature published until June 2023 in order to provide an overview of the current knowledge of the connection between H2S and IBD.

CaMK1D signalling in AgRP neurons promotes ghrelin-mediated food intake.

Hypothalamic AgRP/NPY neurons are key players in the control of feeding behaviour. Ghrelin, a major orexigenic hormone, activates AgRP/NPY neurons to stimulate food intake and adiposity. However, cell-autonomous ghrelin-dependent signalling mechanisms in AgRP/NPY neurons remain poorly defined. Here we show that calcium/calmodulin-dependent protein kinase ID (CaMK1D), a genetic hot spot in type 2 diabetes, is activated upon ghrelin stimulation and acts in AgRP/NPY neurons to mediate ghrelin-dependent food intake. Global Camk1d-knockout male mice are resistant to ghrelin, gain less body weight and are protected against high-fat-diet-induced obesity. Deletion of Camk1d in AgRP/NPY, but not in POMC, neurons is sufficient to recapitulate above phenotypes. In response to ghrelin, lack of CaMK1D attenuates phosphorylation of CREB and CREB-dependent expression of the orexigenic neuropeptides AgRP/NPY in fibre projections to the paraventricular nucleus (PVN). Hence, CaMK1D links ghrelin action to transcriptional control of orexigenic neuropeptide availability in AgRP neurons.

Comodulation reduces interindividual variability of circuit output.

Ionic current levels of identified neurons vary substantially across individual animals. Yet, under similar conditions, neural circuit output can be remarkably similar, as evidenced in many motor systems. All neural circuits are influenced by multiple neuromodulators which provide flexibility to their output. These neuromodulators often overlap in their actions by modulating the same channel type or synapse, yet have neuron-specific actions resulting from distinct receptor expression. Because of this different receptor expression pattern, in the presence of multiple convergent neuromodulators, a common downstream target would be activated more uniformly in circuit neurons across individuals. We therefore propose that a baseline tonic (non-saturating) level of comodulation by convergent neuromodulators can reduce interindividual variability of circuit output. We tested this hypothesis in the pyloric circuit of the crab, Cancer borealis. Multiple excitatory neuropeptides converge to activate the same voltage-gated current in this circuit, but different subsets of pyloric neurons have receptors for each peptide. We quantified the interindividual variability of the unmodulated pyloric circuit output by measuring the activity phases, cycle frequency and intraburst spike number and frequency. We then examined the variability in the presence of different combinations and concentrations of three neuropeptides. We found that at mid-level concentration (30 nM) but not at near-threshold (1 nM) or saturating (1 µM) concentrations, comodulation by multiple neuropeptides reduced the circuit output variability. Notably, the interindividual variability of response properties of an isolated neuron was not reduced by comodulation, suggesting that the reduction of output variability may emerge as a network effect.

Modulation by neuropeptides with overlapping targets results in functional overlap in oscillatory circuit activation.

Neuromodulation lends flexibility to neural circuit operation but the general notion that different neuromodulators sculpt neural circuit activity into distinct and characteristic patterns is complicated by interindividual variability. In addition, some neuromodulators converge onto the same signaling pathways, with similar effects on neurons and synapses. We compared the effects of three neuropeptides on the rhythmic pyloric circuit in the crab Cancer borealis stomatogastric nervous system. Proctolin (PROC), crustacean cardioactive peptide (CCAP), and red pigment concentrating hormone (RPCH) all activate the same modulatory inward current, IMI, and have convergent actions on synapses. However, while PROC targets all four neuron types in the core pyloric circuit, CCAP and RPCH target the same subset of only two neurons. After removal of spontaneous neuromodulator release, none of the neuropeptides restored the control cycle frequency, but all restored the relative timing between neuron types. Consequently, differences between neuropeptide effects were mainly found in the spiking activity of different neuron types. We performed statistical comparisons using the Euclidean distance in the multidimensional space of normalized output attributes to obtain a single measure of difference between modulatory states. Across preparations, circuit output in PROC was distinguishable from CCAP and RPCH, but CCAP and RPCH were not distinguishable from each other. However, we argue that even between PROC and the other two neuropeptides, population data overlapped enough to prevent reliable identification of individual output patterns as characteristic for a specific neuropeptide. We confirmed this notion by showing that blind classifications by machine learning algorithms were only moderately successful.

Lower respiratory infection in humans caused by pasteurella multocida.

BACKGROUND: Pasteurella (P.) multocida commonly occurs in the upper respiratory tract of healthy domestic pets, especially cats and dogs. People become infected by biting, scratching or direct contact with the animal's saliva. Inflammation develops in the wound and limits itself to the skin and subcutaneous tissue. P. multocida may cause respiratory tract infections and severe life-threatening complications. The study aimed to identify the lower respiratory infection in humans caused by P. multocida, to determine the potential source of infection and the associated symptoms, comorbidities and applied treatment. MATERIALS AND METHODS: Between January 2010 and September 2021, 14,258 patients underwent 16,255 routine flexible video bronchoscopy (FVB), and the same number of bronchoalveolar lavage fluid (BALF) samples for microbiological examination were taken. RESULTS: Microbiological examinations of the BALF only allowed the identification of six patients with P. multocida infection. All persons reported multiple scratches or bites and licking or kissing by their pets in the past. Productive cough with expectoration of mucopurulent discharge was the predominant symptom. CONCLUSIONS: A lower respiratory infection caused by P. multocida is not common in humans. It should be considered particularly in elderly patients with underlying diseases and exposure to cats and dogs.

[Analysis of adverse drug reactions (ADR) in fluorescein angiography (FAG) and indocyanine green angiography (ICGA) and indications before and during the COVID-19 pandemic at a university eye hospital]. / Analyse von unerwünschten Arzneimittelwirkungen (UAW) bei Fluoreszeinangiographie (FAG) und Indocyaningrünangiographie (ICGA) und der Indikationsstellung vor und während der COVID-19-Pandemie an einer Universitätsaugenklinik.

BACKGROUND: This study was an analysis of fluorescein angiography (FAG) and indocyanine green angiography (ICGA) at a university eye hospital. The primary objective of the study was to analyze adverse drug reactions (ADRs) and their severity (mild, moderate, severe). The secondary objective was to investigate the indications of FAG and ICGA before and during the COVID-19 pandemic. METHODS: A retrospective analysis of all FAG and ICGA at the University Eye Hospital in Würzburg from January 2016 to the end of December 2021 was performed. The ADRs, gender, age, examination time points and indications were evaluated. The ADRs were classified into mild, moderate, and severe, following the definition of Kornblau et al. [1] RESULTS: A total of 4900 examinations from 4193 patients were analyzed. An FAG was performed slightly more frequently in men (54.8%) than in women (45.2%) and the mean age was 63.2 ± 16.9 years (median: 65 years). The ADRs occurred in only 1.65% of all FAG, of which 1.27% were mild and 0.39% were moderate. No severe ADRs occurred. The most common ADR was nausea at 59.26%. No ADR occurred in ICGA. The annual number of FAGs averaged 816.7 ± 91.1 and was relatively constant throughout the period except for a significantly reduced number in 2016 (compared with 2018, 2019, and 2021). The most common indication for FAG was venous retinal occlusion at 22.93% (N = 774), showing a significant increase in 2021 compared to 2018-2020. An ICGA was performed in 4.18% of cases, with the most common indication being uveitis at 31.82% (N = 63). CONCLUSION: Compared to other studies very few ADRs occurred and no life-threatening ADR occurred in any case. Venous retinal occlusions were very common indications for FAG, probably due to the frequent need for repeated examinations in this condition. Briefly, during the first lockdown (18 March-8 May 2020), a decrease in angiographies was observed, but over a longer period, no significant differences were seen compared with the prepandemic period.

Outcomes After Left Main Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock (from the German ALKK PCI Registry).

Early revascularization therapy with percutaneous coronary intervention (PCI) has been shown to improve outcomes in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). Data from consecutive patients with AMI and CS treated with PCI enrolled into the prospective Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte-PCI registry were centrally collected and analyzed. Patients were divided into 4 groups with PCI for left main (LM), 1-vessel, 2-vessel, and 3-vessel diseases. Patients' characteristics, procedural features, antithrombotic therapies, and in-hospital complications were compared between the 4 groups. Between 2010 and 2015 a total of 2,348 consecutive patients with AMI and CS were treated by PCI in 51 hospitals, 295 for LM (15 for protected, 280 for unprotected) and single-vessel (n = 491), 2-vessel (n = 524), and 3-vessel disease (n = 1,038). Thrombolysis in myocardial infarction 3 patency of the culprit lesion after PCI was 84.3%, 84.0%, 80.8%, and 84.6% in single-vessel, 2-vessel, 3-vessel disease, and LM PCI, respectively, whereas in-hospital mortality was 27.9%, 33.9%, 46.5%, and 55.9%. Bleeding rates were low (2.0%-2.3 %) and not different between groups. In a multivariate analysis a higher age, thrombolysis in myocardial infarction flow <3 after PCI, 3-vessel disease, and LM PCI were independent predictors of mortality. In conclusion, PCI of the LM is performed in about 12.5% of patients with AMI and CS and was associated with a high procedural success rate, whereas mortality is increased with LM PCI.

The influence of liver transplantation on the interplay between gut microbiome and bile acid homeostasis in children with biliary atresia.

BACKGROUND: Biliary atresia (BA) causes neonatal cholestasis and rapidly progresses into cirrhosis if left untreated. Kasai portoenterostomy may delay cirrhosis. BA remains among the most common indications for liver transplantation (LT) during childhood. Liver function and gut microbiome are interconnected. Disturbed liver function and enterohepatic signaling influence microbial diversity. We, herein, investigate the impact of LT and reestablishment of bile flow on gut microbiome-bile acid homeostasis in children with BA before (pre, n = 10), 3 months (post3m, n = 12), 12 months (post12m, n = 9), and more than 24 months (post24 + m, n = 12) after LT. METHODS: We analyzed the intestinal microbiome of BA patients before and after LT by 16S-rRNA-sequencing and bioinformatics analyses, and serum primary and secondary bile acid levels. RESULTS: The gut microbiome in BA patients exhibits a markedly reduced alpha diversity in pre (p = 0.015) and post3m group (p = 0.044), and approximated healthy control groups at later timepoints post12m (p = 1.0) and post24 + m (p = 0.74). Beta diversity analysis showed overall community structure similarities of pre and post3m (p = 0.675), but both differed from the post24 + m (p < 0.001). Longitudinal analysis of the composition of the gut microbiome revealed the Klebsiella genus to show increased abundance in the post24 + m group compared with an age-matched control (p = 0.029). Secondary bile acid production increased 2+ years after LT (p = 0.03). Multivariable associations of microbial communities and clinical metadata reveal several significant associations of microbial genera with tacrolimus and mycophenolate mofetil-based immunosuppressive regimens. CONCLUSIONS: In children with BA, the gut microbiome shows strongly reduced diversity before and shortly after LT, and approximates healthy controls at later timepoints. Changes in diversity correlate with altered secondary bile acid synthesis at 2+ years and with the selection of different immunosuppressants.

Posterior circulation ischaemic stroke diagnosis and management.

This narrative review provides an overview of the posterior circulation and the clinical features of common posterior circulation stroke (PCS) syndromes in the posterior arterial territories and how to distinguish them from mimics. We outline the hyperacute management of patients with suspected PCS with emphasis on how to identify those who are likely to benefit from intervention based on imaging findings. Finally, we review advances in treatment options, including developments in endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT), and the principles of medical management and indications for neurosurgery. Observational and randomised clinical trial data have been equivocal regarding EVT in PCS, but more recent studies strongly support its efficacy. There have been concomitant advances in imaging of posterior stroke to guide optimal patient selection for thrombectomy. Recent evidence suggests that clinicians should have a heightened suspicion of posterior circulation events with the resultant implementation of timely, evidence-based management.

Genetic Variants Determine Treatment Response in Autoimmune Hepatitis.

BACKGROUND: Autoimmune hepatitis (AIH) is a rare entity; in addition, single-nucleotide polymorphisms (SNPs) may impact its course and outcome. We investigated liver-related SNPs regarding its activity, as well as in relation to its stage and treatment response in a Central European AIH cohort. METHODS: A total of 113 AIH patients (i.e., 30 male/83 female, median 57.9 years) were identified. In 81, genotyping of PNPLA3-rs738409, MBOAT7-rs626238, TM6SF2-rs58542926, and HSD17B13-rs72613567:TA, as well as both biochemical and clinical data at baseline and follow-up, were available. RESULTS: The median time of follow-up was 2.8 years; five patients died and one underwent liver transplantation. The PNPLA3-G/G homozygosity was linked to a worse treatment response when compared to wildtype [wt] (ALT 1.7 vs. 0.6 × ULN, p < 0.001). The MBOAT7-C/C homozygosity was linked to non-response vs. wt and heterozygosity (p = 0.022). Male gender was associated with non-response (OR 14.5, p = 0.012) and a higher prevalence of PNPLA3 (G/G vs. C/G vs. wt 41.9/40.0/15.0% males, p = 0.03). The MBOAT7 wt was linked to less histological fibrosis (p = 0.008), while no effects for other SNPs were noted. A polygenic risk score was utilized comprising all the SNPs and correlated with the treatment response (p = 0.04). CONCLUSIONS: Our data suggest that genetic risk variants impact the treatment response of AIH in a gene-dosage-dependent manner. Furthermore, MBOAT7 and PNPLA3 mediated most of the observed effects, the latter explaining, in part, the predisposition of male subjects to worse treatment responses.

Primary and secondary data in emergency medicine health services research - a comparative analysis in a regional research network on multimorbid patients.

BACKGROUND: This analysis addresses the characteristics of two emergency department (ED) patient populations defined by three model diseases (hip fractures, respiratory, and cardiac symptoms) making use of survey (primary) and routine (secondary) data from hospital information systems (HIS). Our aims were to identify potential systematic inconsistencies between both data samples and implications of their use for future ED-based health services research. METHODS: The research network EMANET prospectively collected primary data (n=1442) from 2017-2019 and routine data from 2016 (n=9329) of eight EDs in a major German city. Patient populations were characterized using socio-structural (age, gender) and health- and care-related variables (triage, transport to ED, case and discharge type, multi-morbidity). Statistical comparisons between descriptive results of primary and secondary data samples for each variable were conducted using binomial test, chi-square goodness-of-fit test, or one-sample t-test according to scale level. RESULTS: Differences in distributions of patient characteristics were found in nearly all variables in all three disease populations, especially with regard to transport to ED, discharge type and prevalence of multi-morbidity. Recruitment conditions (e.g., patient non-response), project-specific inclusion criteria (e.g., age and case type restrictions) as well as documentation routines and practices of data production (e.g., coding of diagnoses) affected the composition of primary patient samples. Time restrictions of recruitment procedures did not generate meaningful differences regarding the distribution of characteristics in primary and secondary data samples. CONCLUSIONS: Primary and secondary data types maintain their advantages and shortcomings in the context of emergency medicine health services research. However, differences in the distribution of selected variables are rather small. The identification and classification of these effects for data interpretation as well as the establishment of monitoring systems in the data collection process are pivotal. TRIAL REGISTRATION: DRKS00011930 (EMACROSS), DRKS00014273 (EMAAGE), NCT03188861 (EMASPOT).

Effort-reward imbalance and its association with sociocultural diversity factors at work: findings from a cross-sectional survey among physicians and nurses in Germany.

OBJECTIVE: Due to staff shortages and reports of high work stress, work conditions of hospital physicians and nurses receive wide attention. Additionally, sociocultural diversity of the workforce and patient population is increasing. Our study aim is to analyze how individual and organizational diversity-related factors are associated with the experience of staff's work stress. METHODS: A cross-sectional online survey was conducted with healthcare staff from 22 acute hospitals operated by two healthcare organizations in Germany in 2018. Sociodemographic, occupational and organizational factors were surveyed. Participants further reported work conditions related to the sociocultural diversity of colleagues and patients. Effort-reward imbalance (ERI) was measured with the German short version. Multivariable regression models were calculated with ER ratio as an outcome. RESULTS: N = 800 healthcare staff were included. Variables associated with higher ERI were longer work experience (ß = 0.092, p < 0.05), not holding a leading position (0.122, < 0.01), being a witness (0.149, < 0.001) or victim (0.099, < 0.05) of discrimination at one's own ward, reporting frequent burden due to language barriers with patients (0.102, < 0.01) and colleagues (0.127, < 0.001), and having restricted access to translators at work (0.175, < 0.001). Factors associated with lower ERI were having a first generation migration background (- 0.095, < 0.05) and being a physician (- 0.112, < 0.05). CONCLUSIONS: Catering to the needs of healthcare personnel in dealing with the additional effort related to language barriers at work, e.g., readily available translator services, and creating non-discriminatory work environments might be one cornerstone for the prevention of work-related ill health and retention of qualified hospital staff.

Cerebroprotection in the endovascular era: an update.

Despite advances in clinical diagnosis and increasing numbers of patients eligible for revascularisation, ischaemic stroke remains a significant public health concern accounting for 3.3 million deaths annually. In addition to recanalisation therapy, patient outcomes could be improved through cerebroprotection, but all translational attempts have remained unsuccessful. In this narrative review, we discuss potential reasons for those failures. We then outline the diverse, multicellular effects of ischaemic stroke and the complex temporal sequences of the pathophysiological cascade during and following ischaemia, reperfusion, and recovery. This evidence is linked with findings from prior cerebroprotective trials and interpreted for the modern endovascular era. Future cerebroprotective agents that are multimodal and multicellular, promoting cellular and metabolic health to different targets at time points that are most responsive to treatment, might prove more successful.

Epigenetics of traumatic stress: The association of NR3C1 methylation and posttraumatic stress disorder symptom changes in response to narrative exposure therapy.

Epigenetic processes allow plasticity in gene regulation in response to significant environmental events. Accumulating evidence suggests that effective psychotherapy is accompanied by epigenetic changes, rendering DNA methylation a potential biomarker of therapy success. Due to the central role of glucocorticoid dynamics in stress regulation and the alteration of aversive memories, glucocorticoid receptors are likely involved in the molecular processes that are required to successfully treat Posttraumatic Stress Disorder (PTSD). This study aimed to investigate the relationship between methylation at the glucocorticoid receptor gene (NR3C1) and PTSD treatment success of evidence-based psychotherapy. A sample of N = 153 conflict survivors from Northern Uganda (98 females and 55 males) with PTSD were treated with Narrative Exposure Therapy (NET). Diagnostic interviews and saliva sampling took place at pretreatment and 4 and 10 months after treatment completion. We investigated potential associations between PTSD symptom development and methylation changes at 38 CpG sites spanning NR3C1 over the three times of measurement using the repeated measures correlation. After accounting for multiple comparisons, DNA methylation at CpG site cg25535999 remained negatively associated with PTSD symptoms. These results were followed up by mixed models as well as structural equation modelling. These analyses revealed that treatment responders had a significant cg25535999 methylation increase after treatment with NET. Furthermore, lower methylation at cg25535999 pretreatment predicted a higher symptom improvement. Our results suggest different epigenetic profile dynamics at NR3C1 cg25535999 in therapy responders compared to non-responders and underscore the central role of glucocorticoid signaling in trauma-focused therapy.

Remembering the Work of Phillip L. Geissler: A Coda to His Scientific Trajectory.

Phillip L. Geissler made important contributions to the statistical mechanics of biological polymers, heterogeneous materials, and chemical dynamics in aqueous environments. He devised analytical and computational methods that revealed the underlying organization of complex systems at the frontiers of biology, chemistry, and materials science. In this retrospective we celebrate his work at these frontiers.

Developing a metabolic clearance rate framework as a translational analysis approach for hyperpolarized 13C magnetic resonance imaging.

Hyperpolarized carbon-13 magnetic resonance imaging is a promising technique for in vivo metabolic interrogation of alterations between health and disease. This study introduces a formalism for quantifying the metabolic information in hyperpolarized imaging. This study investigated a novel perfusion formalism and metabolic clearance rate (MCR) model in pre-clinical stroke and in the healthy human brain. Simulations showed that the proposed model was robust to perturbations in T1, transmit B1, and kPL. A significant difference in ipsilateral vs contralateral pyruvate derived cerebral blood flow (CBF) was detected in rats (140 ± 2 vs 89 ± 6 mL/100 g/min, p < 0.01, respectively) and pigs (139 ± 12 vs 95 ± 5 mL/100 g/min, p = 0.04, respectively), along with an increase in fractional metabolism (26 ± 5 vs 4 ± 2%, p < 0.01, respectively) in the rodent brain. In addition, a significant increase in ipsilateral vs contralateral MCR (0.034 ± 0.007 vs 0.017 ± 0.02/s, p = 0.03, respectively) and a decrease in mean transit time (31 ± 8 vs 60 ± 2 s, p = 0.04, respectively) was observed in the porcine brain. In conclusion, MCR mapping is a simple and robust approach to the post-processing of hyperpolarized magnetic resonance imaging.