Microglial activation, tau and amyloid deposition in TREM2 p.R47H carriers and mild cognitive impairment patients: a multi-modal/multi-tracer PET/MRI imaging study with influenza vaccine immune challenge.

BACKGROUND: Microglia are increasingly understood to play an important role in the pathogenesis of Alzheimer's disease. The rs75932628 (p.R47H) TREM2 variant is a well-established risk factor for Alzheimer's disease. TREM2 is a microglial cell surface receptor. In this multi-modal/multi-tracer PET/MRI study we investigated the effect of TREM2 p.R47H carrier status on microglial activation, tau and amyloid deposition, brain structure and cognitive profile. METHODS: We compared TREM2 p.R47H carriers (n = 8; median age = 62.3) and participants with mild cognitive impairment (n = 8; median age = 70.7). Participants underwent two [18F]DPA-714 PET/MRI scans to assess TSPO signal, indicative of microglial activation, before and after receiving the seasonal influenza vaccination, which was used as an immune stimulant. Participants also underwent [18F]florbetapir and [18F]AV1451 PET scans to assess amyloid and tau burden, respectively. Regional tau and TSPO signal were calculated for regions of interest linked to Braak stage. An additional comparison imaging healthy control group (n = 8; median age = 45.5) had a single [18F]DPA-714 PET/MRI. An expanded group of participants underwent neuropsychological testing, to determine if TREM2 status influenced clinical phenotype. RESULTS: Compared to participants with mild cognitive impairment, TREM2 carriers had lower TSPO signal in Braak II (P = 0.04) and Braak III (P = 0.046) regions, despite having a similar burden of tau and amyloid. There were trends to suggest reduced microglial activation following influenza vaccine in TREM2 carriers. Tau deposition in the Braak VI region was higher in TREM2 carriers (P = 0.04). Furthermore, compared to healthy controls TREM2 carriers had smaller caudate (P = 0.02), total brain (P = 0.049) and white matter volumes (P = 0.02); and neuropsychological assessment revealed worse ADAS-Cog13 (P = 0.03) and Delayed Matching to Sample (P = 0.007) scores. CONCLUSIONS: TREM2 p.R47H carriers had reduced levels of microglial activation in brain regions affected early in the Alzheimer's disease course and differences in brain structure and cognition. Changes in microglial response may underlie the increased Alzheimer's disease risk in TREM2 p.R47H carriers. Future therapeutic agents in Alzheimer's disease should aim to enhance protective microglial actions.

Impact of maternal body mass index and gestational weight gain on maternal and neonatal outcomes in twin pregnancies.

INTRODUCTION: To date, there have only been provisional recommendations about the appropriate gestational weight gain in twin pregnancies. This study aimed to contribute evidence to this gap of knowledge. MATERIAL AND METHODS: Using a cohort of 10 603 twin pregnancies delivered between 2000 and 2015 in the state of Hessen, Germany, the individual and combined impact of maternal body mass index and gestational weight gain on maternal and neonatal outcomes was analyzed using uni- and multivariable logistic regression models. The analysis used newly defined population-based quartiles of gestational weight gain in women carrying twin pregnancies (Q1: <419.4 g/week [low weight gain], Q2-Q3: 419.4-692.3 g/week [optimal weight gain], Q4: >692.3 g/week [high weight gain]) and the World Health Organization body mass index classification. RESULTS: Pre-pregnancy body mass index ≥25 kg/m2 was associated with significantly increased rates of cesarean deliveries (aOR1.2, 95% CI: 1.01-1.41) and pregnancy-induced hypertensive disorders (aOR 1.53, 95% CI: 1.11-2.1) but not with any adverse neonatal outcome. Perinatal mortality (aOR 2.23, 95% CI: 1.38-3.6), preterm birth (aOR 1.88, 95% CI: 1.58-2.25), APGAR'5 < 7 (aOR 1.61, 95% CI: 1.19-2.17) and admissions to the neonatal intensive care unit (aOR 1.6, CI: 1.38-1.85) were increased among women with low gestational weight gain. Rates of cesarean deliveries were high in both women with low (aOR 1.25, 95% CI: 1.05-1.48) and high gestational weight gain (aOR 1.17, 95% CI: 1.01-1.35). A high gestational weight gain was also associated with higher rates of hypertensive disorders in pregnancy (aOR 2.32, 95% CI: 1.79-3.02) and postpartum hemorrhage (aOR 1.72, 95%CI: 1.12-2.63). The risk of preterm birth, low Apgar scores and NICU admissions showed a converse linear relation with pre-pregnancy body mass index in women with low gestational weight gain. CONCLUSIONS: In twin pregnancies, nonoptimal weekly maternal weight gain seems to be strongly associated with maternal and neonatal adverse outcomes. Since gestational weight gain is a modifiable risk factor, health care providers have the opportunity to counsel pregnant women with twins and target their care accordingly. Additional research to confirm the validity and generalizability of our findings in different populations is warranted.

The blood-CSF-brain route of neurological disease: The indirect pathway into the brain.

The brain is protected by the endothelial blood-brain barrier (BBB) that limits the access of micro-organisms, tumour cells, immune cells and autoantibodies to the parenchyma. However, the classic model of disease spread across a disrupted BBB does not explain the focal distribution of lesions seen in a variety of neurological diseases and why lesions are frequently adjacent to the cerebrospinal fluid (CSF) spaces. We have critically reviewed the possible role of a blood-CSF-brain route as a disease entry pathway into the brain parenchyma. The initial step of this pathway is the transfer of pathogens or immune components from the blood into the CSF at the choroid plexuses, where the blood-CSF barrier (BCSFB) is located. The flow of CSF results in disease dissemination throughout the CSF spaces. Access to the brain parenchyma from the CSF can then occur across the ependymal layer at the ventricular surface or across the pial-glial barrier of the subarachnoid space and the Virchow-Robin spaces. We have reviewed the anatomy and physiology of the blood-CSF-brain pathway and the brain barriers controlling this process. We then summarised the evidence supporting this brain entry route in a cross-section of neurological diseases including neuromyelitis optica, multiple sclerosis, neurosarcoidosis, neuropsychiatric lupus, cryptococcal infection and both solid and haematological tumours. This summary highlights the conditions that share the blood-CSF-brain pathway as a pathogenetic mechanism. These include the characteristic proximity of lesions to CSF, evidence of disruption of the brain barriers and the identification of significant pathology within the CSF. An improved understanding of pathological transfer through the CSF and across all brain barriers will inform on more effective and targeted treatments of primary and secondary diseases of the central nervous system.

Supervised clustering for TSPO PET imaging.

PURPOSE: This technical note seeks to act as a practical guide for implementing a supervised clustering algorithm (SVCA) reference region approach and to explain the main strengths and limitations of the technique in the context of 18-kilodalton translocator protein (TSPO) positron emission tomography (PET) studies in experimental medicine. BACKGROUND: TSPO PET is the most widely used imaging technique for studying neuroinflammation in vivo in humans. Quantifying neuroinflammation with PET can be a challenging and invasive procedure, especially in frail patients, because it often requires blood sampling from an arterial catheter. A widely used alternative to arterial sampling is SVCA, which identifies the voxels with minimal specific binding in the PET images, thus extracting a pseudo-reference region for non-invasive quantification. Unlike other reference region approaches, SVCA does not require specification of an anatomical reference region a priori, which alleviates the limitation of TSPO contamination in anatomically-defined reference regions in individuals with underlying inflammatory processes. Furthermore, SVCA can be applied to any TSPO PET tracer across different neurological and neuropsychiatric conditions, providing noninvasivequantification of TSPO expression. METHODS: We provide an overview of the development of SVCA as well as step-by-step instructions for implementing SVCA with suggestions for specific settings. We review the literature on SVCAapplications using first- and second- generation TSPO PET tracers and discuss potential clinically relevant limitations and applications. CONCLUSIONS: The correct implementation of SVCA can provide robust and reproducible estimates of brain TSPO expression. This review encourages the standardisation of SVCA methodology in TSPO PET analysis, ultimately aiming to improve replicability and comparability across study sites.

Increased serum peripheral C-reactive protein is associated with reduced brain barriers permeability of TSPO radioligands in healthy volunteers and depressed patients: implications for inflammation and depression.

The relationship between peripheral and central immunity and how these ultimately may cause depressed behaviour has been the focus of a number of imaging studies conducted with Positron Emission Tomography (PET). These studies aimed at testing the immune-mediated model of depression that proposes a direct effect of peripheral cytokines and immune cells on the brain to elicit a neuroinflammatory response via a leaky blood-brain barrier and ultimately depressive behaviour. However, studies conducted so far using PET radioligands targeting the neuroinflammatory marker 18 kDa translocator protein (TSPO) in patient cohorts with depression have demonstrated mild inflammatory brain status but no correlation between central and peripheral immunity. To gain a better insight into the relationship between heightened peripheral immunity and neuroinflammation, we estimated blood-to-brain and blood-to-CSF perfusion rates for two TSPO radiotracers collected in two separate studies, one large cross-sectional study of neuroinflammation in normal and depressed cohorts (N = 51 patients and N = 25 controls) and a second study where peripheral inflammation in N = 7 healthy controls was induced via subcutaneous injection of interferon (IFN)-α. In both studies we observed a consistent negative association between peripheral inflammation, measured with c-reactive protein P (CRP), and radiotracer perfusion into and from the brain parenchyma and CSF. Importantly, there was no association of this effect with the marker of BBB leakage S100ß, that was unchanged. These results suggest a different model of peripheral-to-central immunity interaction whereas peripheral inflammation may cause a reduction in BBB permeability. This effect, on the long term, is likely to disrupt brain homeostasis and induce depressive behavioural symptoms.

Challenges for better care based on the course of maternal body mass index, weight gain and multiple outcome in twin pregnancies: a population-based retrospective cohort study in Hessen/Germany within 15 years.

INTRODUCTION: Studies on maternal weight, gestational weight gain and associated outcomes in twin pregnancies are scarce. Therefore, we analyzed these items in a large cohort. METHODS: Data from 10,603/13,725 total twin pregnancies from the perinatal database in Hessen, Germany between 2000 and 2015 were used after exclusion of incomplete or non-plausible data sets. The course of maternal and perinatal outcomes was evaluated by linear and logistic regression models. RESULTS: The rate of twin pregnancies increased from 1.5 to 1.9% (p < 0.00001). Mean maternal age and pre-pregnancy weight rose from 31.4 to 32.9 years and from 68.2 to 71.2 kg, respectively (p < 0.001). The rates of women with a body mass index ≥ 30 kg/m2 increased from 11.9 to 16.9% with a mean of 24.4-25.4 kg/m2 (p < 0.001). The overall increase of maternal weight/week was 568 g, the 25th quartile was 419, the 75th quartile 692 g/week. The total and secondary caesareans increased from 68.6 to 73.3% and from 20.6 to 39.8%, respectively (p < 0.001). Rates of birthweight < 1500 g and of preterm birth < 28 and from 28 to 33 + 6 weeks all increased (p < 0.01). No significant changes were observed in the rates of stillbirth, perinatal mortality and NICU admissions. CONCLUSION: The global trend of the obesity epidemic is equally observed in German twin pregnancies. The increase of mean maternal weight and the calculated quartiles specific for twin pregnancies help to identify inadequate weight gain in twin gestations. Policy makers should be aware of future health risks specified for singleton and twin gestations.

Spontaneous Chloroplast Mutants Mostly Occur by Replication Slippage and Show a Biased Pattern in the Plastome of Oenothera.

Spontaneous plastome mutants have been used as a research tool since the beginning of genetics. However, technical restrictions have severely limited their contributions to research in physiology and molecular biology. Here, we used full plastome sequencing to systematically characterize a collection of 51 spontaneous chloroplast mutants in Oenothera (evening primrose). Most mutants carry only a single mutation. Unexpectedly, the vast majority of mutations do not represent single nucleotide polymorphisms but are insertions/deletions originating from DNA replication slippage events. Only very few mutations appear to be caused by imprecise double-strand break repair, nucleotide misincorporation during replication, or incorrect nucleotide excision repair following oxidative damage. U-turn inversions were not detected. Replication slippage is induced at repetitive sequences that can be very small and tend to have high A/T content. Interestingly, the mutations are not distributed randomly in the genome. The underrepresentation of mutations caused by faulty double-strand break repair might explain the high structural conservation of seed plant plastomes throughout evolution. In addition to providing a fully characterized mutant collection for future research on plastid genetics, gene expression, and photosynthesis, our work identified the spectrum of spontaneous mutations in plastids and reveals that this spectrum is very different from that in the nucleus.

Adjuvant gemcitabine-docetaxel chemotherapy for stage I uterine leiomyosarcoma: Trends and survival outcomes.

OBJECTIVE: To assess recent trends of administering adjuvant gemcitabine-docetaxel (GD) chemotherapy for Stage I uterine leiomyosarcoma, and to compare disease-free and overall survival between women who received and did not receive adjuvant GD chemotherapy. METHODS: All patients diagnosed with Stage I uterine leiomyosarcoma in a California-Colorado population-based health plan inclusive of 2006-2013 were included in a retrospective cohort. Adjuvant GD chemotherapy rates, clinico-pathologic characteristics and survival estimates were assessed. RESULTS: Of 111 women with Stage I uterine leiomyosarcoma, 33 received adjuvant GD (median 4cycles), 77 received no chemotherapy, and 1 patient excluded for non-GD chemotherapy. GD-chemotherapy and no-chemotherapy groups were similar with respect to age, stage (IA/IB), uterine weight, mitotic index, body mass index, and Charlson comorbidity score. Non-Hispanic white women were twice as likely to receive adjuvant chemotherapy as non-white or Hispanic women (37.7 vs. 17.1%, P=0.02). The proportion of women receiving adjuvant GD chemotherapy increased from 6.5% in 2006-2008 to 46.9% in 2009-2013 (P<0.001). There was no significance difference in unadjusted Kaplan-Meyer estimated disease-free (P=0.95) or overall survival (P=0.43) between GD-chemotherapy and no-chemotherapy cohorts. Corresponding adjusted Cox proportional hazard ratios for adjuvant GD chemotherapy compared to no chemotherapy were 1.01 (95% confidence interval [CI] 0.57-1.80, P=0.97) for recurrence and 1.28 (95% CI 0.69-2.36, P-0.48) for mortality. CONCLUSIONS: Use of adjuvant GD chemotherapy for Stage I uterine leiomyosarcoma has increased significantly in the last decade, despite unclear benefit. Compared to no chemotherapy, 4-6cycles of adjuvant GD chemotherapy does not appear to alter survival outcomes.

Expression of heterologous xyloglucan xylosyltransferases in Arabidopsis to investigate their role in determining xyloglucan xylosylation substitution patterns.

MAIN CONCLUSION: Putative XyG xylosyltransferases from Tropaeolum majus (nasturtium) and Solanum lycopersicum (tomato) homologous to characterized Arabidopsis genes were identified and shown to functionally complement Arabidopsis mutants lacking xyloglucan demonstrating they represent xyloglucan xylosyltransferases. Xyloglucan is a major hemicellulose in the plant cell wall and is important for the structural organization of the wall. The fine structure of xyloglucan can vary dependent on plant species and tissue type. Most vascular seed-bearing plants including Arabidopsis thaliana and nasturtium (Tropaeolum majus) have a xyloglucan structure, in which three out of four backbone glucosyl-residues are substituted with xylosyl-residues. In contrast, the xyloglucan found in plants of the Solanaceae family, which includes tomato (Solanum lycopersicum), is typically less xylosylated with only two of the four backbone glucosyl-residues substituted with xylosyl-residues. To investigate the genetics of xyloglucan xylosylation, candidate xyloglucan xylosyltransferase genes (XXTs) homologous to known A. thaliana XXTs were cloned from nasturtium and tomato. These candidate XXTs were expressed in the A. thaliana xxt1/2 double and xxt1/2/5 triple mutant, whose walls lack detectable xyloglucan. Expression of the orthologs of XXT5 resulted in no detectable xyloglucan in the transgenic A. thaliana plants, consistent with a lack of xyloglucan in the A. thaliana xxt1/2 double mutant. However, transformation of both the tomato and nasturtium orthologs of AtXXT1 and AtXXT2 resulted in the production of xyloglucan with a xylosylation pattern similar to wild type A. thaliana indicating that both SlXXT2 and TmXXT2 likely have xylosyltransferase activity. As the expression of the SlXXT2 did not result in xyloglucan with a decreased xylosylation frequency found in tomato, this gene is not responsible for the unique xylosylation pattern found in the solanaceous plants.

ASCHOPLEX: A generalizable approach for the automatic segmentation of choroid plexus.

BACKGROUND: The Choroid Plexus (ChP) plays a vital role in brain homeostasis, serving as part of the Blood-Cerebrospinal Fluid Barrier, contributing to brain clearance pathways and being the main source of cerebrospinal fluid. Since the involvement of ChP in neurological and psychiatric disorders is not entirely established and currently under investigation, accurate and reproducible segmentation of this brain structure on large cohorts remains challenging. This paper presents ASCHOPLEX, a deep-learning tool for the automated segmentation of human ChP from structural MRI data that integrates existing software architectures like 3D UNet, UNETR, and DynUNet to deliver accurate ChP volume estimates. METHODS: Here we trained ASCHOPLEX on 128 T1-w MRI images comprising both controls and patients with Multiple Sclerosis. ASCHOPLEX's performances were evaluated using traditional segmentation metrics; manual segmentation by experts served as ground truth. To overcome the generalizability problem that affects data-driven approaches, an additional fine-tuning procedure (ASCHOPLEXtune) was implemented on 77 T1-w PET/MRI images of both controls and depressed patients. RESULTS: ASCHOPLEX showed superior performance compared to commonly used methods like FreeSurfer and Gaussian Mixture Model both in terms of Dice Coefficient (ASCHOPLEX 0.80, ASCHOPLEXtune 0.78) and estimated ChP volume error (ASCHOPLEX 9.22%, ASCHOPLEXtune 9.23%). CONCLUSION: These results highlight the high accuracy, reliability, and reproducibility of ASCHOPLEX ChP segmentations.

A blood-free modeling approach for the quantification of the blood-to-brain tracer exchange in TSPO PET imaging.

Introduction: Recent evidence suggests the blood-to-brain influx rate (K1 ) in TSPO PET imaging as a promising biomarker of blood-brain barrier (BBB) permeability alterations commonly associated with peripheral inflammation and heightened immune activity in the brain. However, standard compartmental modeling quantification is limited by the requirement of invasive and laborious procedures for extracting an arterial blood input function. In this study, we validate a simplified blood-free methodologic framework for K1 estimation by fitting the early phase tracer dynamics using a single irreversible compartment model and an image-derived input function (1T1K-IDIF). Methods: The method is tested on a multi-site dataset containing 177 PET studies from two TSPO tracers ([11C]PBR28 and [18F]DPA714). Firstly, 1T1K-IDIF K1 estimates were compared in terms of both bias and correlation with standard kinetic methodology. Then, the method was tested on an independent sample of [11C]PBR28 scans before and after inflammatory interferon-α challenge, and on test-retest dataset of [18F]DPA714 scans. Results: Comparison with standard kinetic methodology showed good-to-excellent intra-subject correlation for regional 1T1K-IDIF-K1 (ρintra = 0.93 ± 0.08), although the bias was variable depending on IDIF ability to approximate blood input functions (0.03-0.39 mL/cm3/min). 1T1K-IDIF-K1 unveiled a significant reduction of BBB permeability after inflammatory interferon-α challenge, replicating results from standard quantification. High intra-subject correlation (ρ = 0.97 ± 0.01) was reported between K1 estimates of test and retest scans. Discussion: This evidence supports 1T1K-IDIF as blood-free alternative to assess TSPO tracers' unidirectional blood brain clearance. K1 investigation could complement more traditional measures in TSPO studies, and even allow further mechanistic insight in the interpretation of TSPO signal.

Brain Fluid Clearance After Traumatic Brain Injury Measured Using Dynamic Positron Emission Tomography.

Brain fluid clearance by pathways including the recently described paravascular glymphatic system is a critical homeostatic mechanism by which metabolic products, toxins, and other wastes are removed from the brain. Brain fluid clearance may be especially important after traumatic brain injury (TBI), when blood, neuronal debris, inflammatory cells, and other substances can be released and/or deposited. Using a non-invasive dynamic positron emission tomography (PET) method that models the rate at which an intravenously injected radiolabeled molecule (in this case 11C-flumazenil) is cleared from ventricular cerebrospinal fluid (CSF), we estimated the overall efficiency of brain fluid clearance in humans who had experienced complicated-mild or moderate TBI 3-6 months before neuroimaging (n = 7) as compared to healthy controls (n = 9). While there was no significant difference in ventricular clearance between TBI subjects and controls, there was a significant group difference in dependence of ventricular clearance upon tracer delivery/blood flow to the ventricles. Specifically, in controls, ventricular clearance was highly, linearly dependent upon blood flow to the ventricle, but this relation was disrupted in TBI subjects. When accounting for blood flow and group-specific alterations in blood flow, ventricular clearance was slightly (non-significantly) increased in TBI subjects as compared to controls. Current results contrast with past studies showing reduced glymphatic function after TBI and are consistent with possible differential effects of TBI on glymphatic versus non-glymphatic clearance mechanisms. Further study using multi-modal methods capable of assessing and disentangling blood flow and different aspects of fluid clearance is needed to clarify clearance alterations after TBI.

Risk Factors for Maternal Body Mass Index and Gestational Weight Gain in Twin Pregnancies.

Objective This retrospective cohort study analyzes risk factors for abnormal pre-pregnancy body mass index and abnormal gestational weight gain in twin pregnancies. Methods Data from 10 603/13 682 twin pregnancies were analyzed using uni- and multivariable logistic regression models to determine risk factors for abnormal body mass index and weight gain in pregnancy. Results Multiparity was associated with pre-existing obesity in twin pregnancies (aOR: 3.78, 95% CI: 2.71 - 5.27). Working in academic or leadership positions (aOR: 0.57, 95% CI: 0.45 - 0.72) and advanced maternal age (aOR: 0.96, 95% CI: 0.95 - 0.98) were negatively associated with maternal obesity. Advanced maternal age was associated with a lower risk for maternal underweight (aOR: 0.95, 95% CI: 0.92 - 0.99). Unexpectedly, advanced maternal age (aOR: 0.98, 95% CI: 0.96 - 0.99) and multiparity (aOR: 0.6, 95% CI: 0.41 - 0.88) were also associated with lower risks for high gestational weight gain. Pre-existing maternal underweight (aOR: 1.55, 95% CI: 1.07 - 2.24), overweight (aOR: 1.61, 95% CI: 1.39 - 1.86), obesity (aOR: 3.09, 95% CI: 2.62 - 3.65) and multiparity (aOR: 1.64, 95% CI: 1.23 - 2.18) were all associated with low weight gain. Women working as employees (aOR: 0.85, 95% CI: 0.73 - 0.98) or in academic or leadership positions were less likely to have a low gestational weight gain (aOR: 0.77, 95% CI: 0.64 - 0.93). Conclusion Risk factors for abnormal body mass index and gestational weight gain specified for twin pregnancies are relevant to identify pregnancies with increased risks for poor maternal or neonatal outcome and to improve their counselling. Only then, targeted interventional studies in twin pregnancies which are desperately needed can be performed.

Choroid plexus enlargement is associated with neuroinflammation and reduction of blood brain barrier permeability in depression.

BACKGROUND: Recent studies have shown that choroid plexuses (CP) may be involved in the neuro-immune axes, playing a role in the interaction between the central and peripheral inflammation. Here we aimed to investigate CP volume alterations in depression and their associations with inflammation. METHODS: 51 depressed participants (HDRS score > 13) and 25 age- and sex-matched healthy controls (HCs) from the Wellcome Trust NIMA consortium were re-analysed for the study. All the participants underwent full peripheral cytokine profiling and simultaneous [11C]PK11195 PET/structural MRI imaging for measuring neuroinflammation and CP volume respectively. RESULTS: We found a significantly greater CP volume in depressed subjects compared to HCs (t(76) = +2.17) that was positively correlated with [11C]PK11195 PET binding in the anterior cingulate cortex (r = 0.28, p = 0.02), prefrontal cortex (r = 0.24, p = 0.04), and insular cortex (r = 0.24, p = 0.04), but not with the peripheral inflammatory markers: CRP levels (r = 0.07, p = 0.53), IL-6 (r = -0.08, p = 0.61), and TNF-α (r = -0.06, p = 0.70). The CP volume correlated with the [11C]PK11195 PET binding in CP (r = 0.34, p = 0.005). Integration of transcriptomic data from the Allen Human Brain Atlas with the brain map depicting the correlations between CP volume and PET imaging found significant gene enrichment for several pathways involved in neuroinflammatory response. CONCLUSION: This result supports the hypothesis that changes in brain barriers may cause reduction in solute exchanges between blood and CSF, disturbing the brain homeostasis and ultimately contributing to inflammation in depression. Given that CP anomalies have been recently detected in other brain disorders, these results may not be specific to depression and might extend to other conditions with a peripheral inflammatory component.

Reproducibility of findings in modern PET neuroimaging: insight from the NRM2018 grand challenge.

The reproducibility of findings is a compelling methodological problem that the neuroimaging community is facing these days. The lack of standardized pipelines for image processing, quantification and statistics plays a major role in the variability and interpretation of results, even when the same data are analysed. This problem is well-known in MRI studies, where the indisputable value of the method has been complicated by a number of studies that produce discrepant results. However, any research domain with complex data and flexible analytical procedures can experience a similar lack of reproducibility. In this paper we investigate this issue for brain PET imaging. During the 2018 NeuroReceptor Mapping conference, the brain PET community was challenged with a computational contest involving a simulated neurotransmitter release experiment. Fourteen international teams analysed the same imaging dataset, for which the ground-truth was known. Despite a plurality of methods, the solutions were consistent across participants, although not identical. These results should create awareness that the increased sharing of PET data alone will only be one component of enhancing confidence in neuroimaging results and that it will be important to complement this with full details of the analysis pipelines and procedures that have been used to quantify data.

A Modest Increase in 11C-PK11195-Positron Emission Tomography TSPO Binding in Depression Is Not Associated With Serum C-Reactive Protein or Body Mass Index.

BACKGROUND: Immune mechanisms have been implicated in the pathogenesis of depression. Translocator protein (TSPO)-targeted positron emission tomography (PET) has been used to assess neuroinflammation in major depressive disorder. We aimed to 1) test the hypothesis of significant case-control differences in TSPO binding in the anterior cingulate cortex, prefrontal cortex, and insula regions; and 2) explore the relationship between cerebral TSPO binding and peripheral blood C-reactive protein (CRP) concentration. METHODS: A total of 51 depressed subjects with Hamilton Depression Rating Scale score >13 (median 17; interquartile range, 16-22) and 25 healthy control subjects underwent dynamic brain 11C-PK11195 PET and peripheral blood immune marker characterization. Depressed subjects were divided into high CRP (>3 mg/L; n = 20) and low CRP (<3 mg/L; n = 31). RESULTS: Across the three regions, TSPO binding was significantly increased in depressed versus control subjects (η2p = .09; F1,71 = 6.97, p = .01), which was not influenced by body mass index. The case-control difference was greatest in the anterior cingulate cortex (d = 0.49; t74 = 2.00, p = .03) and not significant in the prefrontal cortex or insula (d = 0.27 and d = 0.36, respectively). Following CRP stratification, significantly higher TSPO binding was observed in low-CRP depression compared with controls (d = 0.53; t54 = 1.96, p = .03). These effect sizes are comparable to prior major depressive disorder case-control TSPO PET data. No significant correlations were observed between TSPO and CRP measures. CONCLUSIONS: Consistent with previous findings, there is a modest increase in TSPO binding in depressed patients compared with healthy control subjects. The lack of a significant correlation between brain TSPO binding and blood CRP concentration or body mass index poses questions about the interactions between central and peripheral immune responses in the pathogenesis of depression.

Changes in Maternal Body Mass Index, Weight Gain and Outcome of Singleton Pregnancies from 2000 to 2015: A Population-based Retrospective Cohort Study in Hesse/Germany.

Introduction Maternal obesity and excessive gestational weight gain (GWG) affect the outcomes of women and their offspring. Our aim was to evaluate population-based data from Germany. Material and Methods Data from 583 633/791 514 mother-child pairs obtained from the perinatal database in Hesse for the period from 2000 to 2015 were used after excluding incomplete or non-plausible datasets. Early-stage pregnancy maternal body mass index (BMI) and GWG were evaluated. Significant outcome changes were calculated using linear or logistic regression models. Results The mean maternal age increased from 29.9 to 31.28 years; GWG increased from 445.1 to 457.2 g/week (p < 0.01). Similarly, rates for both overweight and obesity rose from 31.5 to 37.5% (p < 0.001). Cesarean section rates rose from 22.8 to 33.2% (p < 0.001) and rates of postpartum hemorrhage increased from 0.6 to 1% (p < 0.001). There was no significant change in the rates for stillbirth or perinatal mortality (p = 0.92 and p = 0.53 respectively), but there was an increase in the rates of admissions to neonatal intensive care units from 7.8 to 9.5% (p < 0.0001). The percentage of newborns with an Apgar score of < 7 at 5 minutes increased from 1 to 1.1% (p < 0.01) and the rate of neonates with an umbilical artery pH of < 7.1 rose from 1.7 to 2.4% (p < 0.01). Conclusions In just 15 years, pre-pregnancy BMI and GWG rates of women with singleton pregnancies have increased, and this increase has been accompanied by a significant rise in the rate of cesarean sections and a significant worsening of short-term maternal and neonatal outcomes. It is time to discuss the risks and the short-term and more worrying long-term consequences for mothers and their offspring and the future impact on our healthcare system.

Acute Stroke Treatment by Surgical Recanalization of Extracranial Internal Carotid Artery Occlusion: A Single Center Experience.

Ischemic stroke due to an acute occlusion of the extracranial internal carotid artery (eICA) is associated with high morbidity and mortality. The best treatment option remains unclear. This study aims to increase the available therapeutic experience documented for surgical recanalization of acute eICA occlusions. We retrospectively reviewed all hospital records of the University Hospital Jena between 2006 and 2018 to identified patients with acute ischemic stroke due to an occlusion of the eICA who underwent emergent surgical recanalization. We analyzed clinical data, surgical reports, imaging data, and outpatient records. The primary outcome parameter was the modified Rankin Scale (mRS) at 3 months. During the survey, 12 patients (mean age: 62.3 ± 10.8 years; range: 35-87) underwent emergent surgical recanalization for an acutely symptomatic eICA occlusion. All patients presented with neurological deficits with a mean National Institutes of Health Stroke Scale score at admission of 15.0 ± 5.1 (range 2-23). Patients were selected for surgery mainly due to the extent of the perfusion mismatch, while stroke severity and age were also considered. The median time from symptom onset to surgery was 309 ± 122 minutes (range 112-650 minutes). Complete recanalization was obtained in all 12 patients. No patient deteriorated postoperatively, no intracranial hemorrhage was observed, and no patient died in the following 3 months. Favorable outcomes (mRS: 0-2) after 3 months were achieved in 7 of 12 patients. The current study adds support to previous findings that the surgical recanalization of acute eICA occlusions is a possible and safe treatment option. However, a critical patient selection based on mismatch size in perfusion imaging is crucially important for successful treatment.

Dynamic 11C-PiB PET Shows Cerebrospinal Fluid Flow Alterations in Alzheimer Disease and Multiple Sclerosis.

Cerebrospinal fluid (CSF) plays an important role in solute clearance and maintenance of brain homeostasis. 11C-Pittsburgh compound B (PiB) PET was recently proposed as a tool for detection of CSF clearance alterations in Alzheimer disease. The current study investigates the magnitude of 11C-PiB PET signal in the lateral ventricles of an independent group of Alzheimer and mild cognitive impairment subjects. We have also evaluated multiple sclerosis as a model of disease with CSF clearance alterations without amyloid-ß tissue accumulation. Methods: A set of 11 Alzheimer and 12 mild cognitive impairment subjects and a set of 20 multiple sclerosis subjects with matched controls underwent MRI and dynamic 11C-PiB PET. Lateral ventricle regions of interest were generated manually from MRI data. PET data were analyzed using cerebellum or a supervised reference region for the Alzheimer and multiple sclerosis data sets, respectively. The magnitude of 11C-PiB signal in the lateral ventricles was calculated as area under the curve from 35 to 80 min and SUV ratio (SUVR) from 50 to 70 min. Compartmental modeling analysis was performed on a separate data set containing 11 Alzheimer and matched control subjects; this analysis included an arterial input function, to further understand the kinetics of the lateral ventricular 11C-PiB signal. Results: ANOVA revealed significant group differences in lateral ventricular SUVR across the Alzheimer, mild cognitive impairment, and healthy control groups (P = 0.004). Pairwise comparisons revealed significantly lower lateral ventricular SUVR in Alzheimer subjects than in healthy controls (P < 0.001) or mild cognitive impairment subjects (P = 0.029). Lateral ventricular SUVR was significantly lower in multiple sclerosis subjects than in healthy controls (P = 0.008). Compartmental modeling analysis revealed significantly lower uptake rates of 11C-PiB signal from blood (P = 0.005) and brain tissue (P = 0.004) to the lateral ventricles and significantly lower 11C-PiB signal clearance out of the lateral ventricles (P = 0.002) in Alzheimer subjects than in healthy controls. Conclusion: These results indicate that dynamic 11C-PiB PET can be used to observe pathologic changes in CSF dynamics. We have replicated previous work demonstrating CSF clearance deficits in Alzheimer disease associated with amyloid-ß deposits and have extended the observations to include ventricular CSF clearance deficits in mild cognitive impairment and multiple sclerosis.

Magnetic resonance spectroscopy evidence for declining gliosis in MS patients treated with ocrelizumab versus interferon beta-1a.

BACKGROUND: Magnetic resonance spectroscopy quantitatively monitors biomarkers of neuron-myelin coupling (N-acetylaspartate (NAA)), and inflammation (total creatine (tCr), total choline (tCho), myo-inositol (mI)) in the brain. OBJECTIVE: This study aims to investigate how ocrelizumab and interferon beta-1a differentially affects imaging biomarkers of neuronal-myelin coupling and inflammation in patients with relapsing multiple sclerosis (MS). METHODS: Forty patients with relapsing MS randomized to either treatment were scanned at 3T at baseline and weeks 24, 48, and 96 follow-up. Twenty-four healthy controls were scanned at weeks 0, 48, and 96. NAA, tCr, tCho, mI, and NAA/tCr were measured in a single large supra-ventricular voxel. RESULTS: There was a time × treatment interaction in NAA/tCr (p = 0.04), primarily driven by opposing tCr trends between treatment groups after 48 weeks of treatment. Patients treated with ocrelizumab showed a possible decline in mI after week 48 week, and stable tCr and tCho levels. Conversely, the interferon beta-1a treated group showed possible increases in mI, tCr, and tCho over 96 weeks. CONCLUSIONS: Results from this exploratory study suggest that over 2 years, ocrelizumab reduces gliosis compared with interferon beta-1a, demonstrated by declining ml, and stable tCr and tCho. Ocrelizumab may improve the physiologic milieu by decreasing neurotoxic factors that are generated by inflammatory processes.