Acute sleep deprivation in mice generates protein pathology consistent with neurodegenerative diseases.

Introduction: Insufficient or disturbed sleep is strongly associated with adverse health conditions, including various neurodegenerative disorders. While the relationship between sleep and neurodegenerative disease is likely bidirectional, sleep disturbances often predate the onset of other hallmark clinical symptoms. Neuronal waste clearance is significantly more efficient during sleep; thus, disturbed sleep may lead to the accumulation of neuronal proteins that underlie neurodegenerative diseases. Key pathological features of neurodegenerative diseases include an accumulation of misfolded or misprocessed variants of amyloid beta (Aß), tau, alpha synuclein (α-syn), and TarDNA binding protein 43 (TDP-43). While the presence of fibrillar protein aggregates of these neuronal proteins are characteristic of neurodegenerative diseases, the presence of small soluble toxic oligomeric variants of these different proteins likely precedes the formation of the hallmark aggregates. Methods: We hypothesized that sleep deprivation would lead to accumulation of toxic oligomeric variants of Aß, tau, α-syn, and TDP-43 in brain tissue of wild-type mice. Adult mice were subjected to 6 h of sleep deprivation (zeitgeber 0-6) for 5 consecutive days or were left undisturbed as controls. Following sleep deprivation, brains were collected, and protein pathology was assessed in multiple brain regions using an immunostain panel of reagents selectively targeting neurodegenerative disease-related variants of Aß, tau, α-syn, and TDP-43. Results: Overall, sleep deprivation elevated levels of all protein variants in at least one of the brain regions of interest. The reagent PDTDP, targeting a TDP-43 variant present in Parkinson's disease, was elevated throughout the brain. The cortex, caudoputamen, and corpus callosum brain regions showed the highest accumulation of pathology following sleep deprivation. Discussion: These data provide a direct mechanistic link between sleep deprivation, and the hallmark protein pathologies of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases.

'The Listening Series': increasing equity, diversity and inclusion in patient and public involvement and engagement for policy research by listening to and learning from under-represented groups.

BACKGROUND: Policy research aims to provide evidence to inform government policy decisions about health and social care. Engaging and involving the public and patients in this work is widely recognised as essential. Research funders prioritise equality, diversity and inclusion (EDI) in patient and public involvement and engagement (PPIE), but people who are most likely to experience poor outcomes are also those least likely to be involved in research. This paper describes our experience of setting out to understand how to overcome barriers to EDI in PPIE in the research carried out by the National Institute for Health and Care Research (NIHR) Policy Research Unit in Maternal and Neonatal Health and Care (PRU-MNHC), in a PPIE consultation project we called The Listening Series. METHODS: We convened five video-recorded online discussion groups involving 20 individuals advocating for groups who are under-represented in our research. Those taking part included people working with Black and Asian women and families, young parents, those from socially deprived backgrounds, and women and families with physical and learning disabilities. Discussions focussed on practical solutions to addressing challenges to people being excluded, and how to improve EDI in our research. LEARNING AND REFLECTION: Five key themes were identified: 'build trust'; 'involve us from the beginning'; 'show us impact'; 'use clear, appropriate and inclusive communication'; and 'imagine life in our shoes'. We used the learning to create a guidance document for researchers and an accompanying 15-minute film. We also took practical steps to embed the learning strategically by expanding our Task Group for PPIE in the PRU-MNHC to include four Listening Series invitees with a remit to champion EDI in our research and ensure that it is embedded in our PPIE activities. We continue to reflect on and work to address the associated challenges. CONCLUSIONS: The Listening Series helped us rethink our processes for inclusion to go beyond traditional methods of involvement and engagement. The themes identified pose challenges that require time, resource and empathic engagement from researchers to be meaningfully resolved. This has implications for policy makers and research funders who need to consider this in their processes.

WHAT WE KNOW: It is important that health care researchers involve patients and the public from a wide range of social and ethnic backgrounds in research, but we know that this often does not happen. We are a group of researchers and patient/public representatives, working in research to improve care for pregnant women and babies. We wanted to find out how to involve people from more diverse backgrounds in our research. WHAT WE DID: We organised five online discussion groups with 20 people working with Black and Asian families, young parents, those from socially deprived backgrounds and parents with physical or learning disabilities. We asked them what we should do to involve a wider range of people in our research. We called this The Listening Series. We summarised the most important things people said in a written guide for researchers and a short film. We then asked people who had been invited to take part in The Listening Series to join us to develop new ways of working together. WHAT WE LEARNED: The five themes we identified were: 'build trust'; 'involve us from the beginning'; 'show us impact'; 'use clear, appropriate and inclusive communication'; and 'imagine life in our shoes'. In summary, researchers need to take the time to build trusting relationships with patients and the public; actively listening and learning from them. This can be challenging for researchers and patient representatives. Research funders need to allow time and money for this to happen in a meaningful way.

Postpartum haemorrhage and risk of cardiovascular disease in later life: A population-based record linkage cohort study.

OBJECTIVE: To investigate the association between postpartum haemorrhage (PPH) and subsequent cardiovascular disease. DESIGN: Population-based retrospective cohort study, using record linkage between Aberdeen Maternity and Neonatal Databank (AMND) and Scottish healthcare data sets. SETTING: Grampian region, Scotland. POPULATION: A cohort of 70 904 women who gave birth after 24 weeks of gestation in the period 1986-2016. METHODS: We used extended Cox regression models to investigate the association between having had one or more occurrences of PPH in any (first or subsequent) births (exposure) and subsequent cardiovascular disease, adjusted for sociodemographic, medical, and pregnancy and birth-related factors. MAIN OUTCOME MEASURES: Cardiovascular disease identified from the prescription of selected cardiovascular medications, hospital discharge records or death from cardiovascular disease. RESULTS: In our cohort of 70 904 women (with 124 795 birth records), 25 177 women (36%) had at least one PPH. Compared with not having a PPH, having at least one PPH was associated with an increased risk of developing cardiovascular disease, as defined above, in the first year after birth (adjusted hazard ratio, aHR 1.96; 95% confidence interval, 95% CI 1.51-2.53; p < 0.001). The association was attenuated over time, but strong evidence of increased risk remained at 2-5 years (aHR 1.19, 95% CI 1.11-1.30, P < 0.001) and at 6-15 years after giving birth (aHR 1.17, 95% CI 1.05-1.30, p = 0.005). CONCLUSIONS: Compared with women who have never had a PPH, women who have had at least one episode of PPH are twice as likely to develop cardiovascular disease in the first year after birth, and some increased risk persists for up to 15 years.

Sleep fragmentation after traumatic brain injury impairs behavior and conveys long-lasting impacts on neuroinflammation.

Traumatic brain injury (TBI) causes a prolonged inflammatory response in the central nervous system (CNS) driven by microglia. Microglial reactivity is exacerbated by stress, which often provokes sleep disturbances. We have previously shown that sleep fragmentation (SF) stress after experimental TBI increases microglial reactivity and impairs hippocampal function 30 days post-injury (DPI). The neuroimmune response is highly dynamic the first few weeks after TBI, which is also when injury induced sleep-wake deficits are detected. Therefore, we hypothesized that even a few weeks of TBI SF stress would synergize with injury induced sleep-wake deficits to promote neuroinflammation and impair outcome. Here, we investigated the effects of environmental SF in a lateral fluid percussion model of mouse TBI. Half of the mice were undisturbed, and half were exposed to 5 h of SF around the onset of the light cycle, daily, for 14 days. All mice were then undisturbed 15-30 DPI, providing a period for SF stress recovery (SF-R). Mice exposed to SF stress slept more than those in control housing 7-14 DPI and engaged in more total daily sleep bouts during the dark period. However, SF stress did not exacerbate post-TBI sleep deficits. Testing in the Morris water maze revealed sex dependent differences in spatial reference memory 9-14 DPI with males performing worse than females. Post-TBI SF stress suppressed neurogenesis-related gene expression and increased inflammatory signaling in the cortex at 14 DPI. No differences in sleep behavior were detected between groups during the SF stress recovery period 15-30 DPI. Microscopy revealed cortical and hippocampal IBA1 and CD68 percent-area increased in TBI SF-R mice 30 DPI. Additionally, neuroinflammatory gene expression was increased, and synaptogenesis-related gene expression was suppressed in TBI-SF mice 30 DPI. Finally, IPA canonical pathway analysis showed post-TBI SF impaired and delayed activation of synapse-related pathways between 14 and 30 DPI. These data show that transient SF stress after TBI impairs recovery and conveys long-lasting impacts on neuroimmune function independent of continuous sleep deficits. Together, these finding support that even limited exposure to post-TBI SF stress can have lasting impacts on cognitive recovery and regulation of the immune response to trauma.

Postnatal care provided by UK midwifery units and the impact of the COVID-19 pandemic: A survey using the UK Midwifery Study System (UKMidSS).

Background: Postnatal care supports healthy transitions to parenthood, mother-infant relationships, and breastfeeding establishment. Highly valued by women and families, it is often an area where parents report low satisfaction compared with other areas of maternity care. Most research about postnatal care is hospital-focused. Little is known about postnatal services provided by midwifery units, and any changes to this provision since the COVID-19 pandemic. Aim: To describe postnatal care services provided by UK midwifery units and examine the extent to which provision was affected by the COVID-19 pandemic. Methods: We carried out a national survey online between January-June 2022 using the United Kingdom Midwifery Study System (UKMidSS). We asked about postnatal care provision in alongside midwifery units (AMU) and freestanding midwifery units (FMU), before the COVID-19 pandemic (July-December 2019) and shortly after restrictions were eased (January-June 2022). Findings: Overall 131 (67 %) midwifery units responded to the survey, 76 (62 %) AMUs and 55 (75 %) FMUs, from 75 % of eligible NHS organisations. In 2022, 66 % of AMUs reported that women typically stayed for 6-24 h after a straightforward birth, while 70 % of FMUs reported typical postnatal stays of <6 h. For 2019, significantly more FMUs reported providing outpatient postnatal services compared with AMUs (98 % vs 57 %, p < 0.001). From 2019 to 2022 there were significant reductions in partners staying overnight in midwifery units (65 %-42 %, p < 0.001), and in the provision of outpatient postnatal breastfeeding groups (23 %-15 %, p < 0.01) and other postnatal groups (7 %-2 %, p = 0.02). Conclusions: The findings document the ways in which postnatal care provision differs between AMUs and FMU, with potential consequences for choice and experience for women. They are also congruent with evidence that maternity care was adversely affected by the COVID-19 pandemic, including a reduction in postnatal visiting for partners and in postnatal group support services.

Nominal Differences in Acute Symptom Presentation and Recovery Duration of Sport-Related Concussion Between Male and Female Collegiate Athletes in the PAC-12.

BACKGROUND: Sport-related concussion (SRC) is a heterogenous injury that often presents with varied symptoms and impairment. Recently, research has focused on identifying subtypes, or clinical profiles of concussion to be used in assessing and treating athletes with SRC. The purpose of this study was to investigate sex differences in clinical profiles, recovery duration, and initial symptom severity after SRC in a cohort of collegiate athletes in the Pacific-12 Conference (Pac-12). METHODS: This prospective cohort study examined post-SRC symptoms, recovery, and return-to-play times using data from the Pac-12 CARE Affiliated Program and Pac-12 Health Analytics Program. Clinical profiles reported by student-athletes were defined by the number (> 50%) of specific symptoms frequently reported for each profile. Generalized linear mixed models were used to examine associations among sex, clinical profiles, time-to-recovery, and return-to-play times. RESULTS: 479 concussion incidents met inclusion criteria. The probabilities of initial presentation of each clinical profile, initial injury severity scores, and recovery times within a profile did not differ between sexes (p = 0.33-0.98). However, both males and females had > 0.75 probabilities of exhibiting cognitive and ocular profiles. Initial injury severity score was a strong nonlinear predictor of initial number of clinical profiles (p < 0.0001), which did not differ between sexes. The number of clinical profiles was also a nonlinear predictor of time-to-recovery (p = 0.03) and return-to-play times (p < 0.0001). CONCLUSIONS: Initial symptom severity was strongly predictive of the number of acute clinical profiles experienced post-SRC. As the number of clinical profiles increased, time-to-recovery and time to return-to-play also increased. Factors other than sex may be better associated with acute symptom presentation post-concussion as no sex differences were found in reported clinical profiles or recovery. Understanding the number and type of clinical profiles experienced post-SRC may help inform concussion diagnostics and management.

Quantifying microglial morphology: an insight into function.

Microglia are specialized immune cells unique to the central nervous system (CNS). Microglia have a highly plastic morphology that changes rapidly in response to injury or infection. Qualitative and quantitative measurements of ever-changing microglial morphology are considered a cornerstone of many microglia-centric research studies. The distinctive morphological variations seen in microglia are a useful marker of inflammation and severity of tissue damage. Although a wide array of damage-associated microglial morphologies has been documented, the exact functions of these distinct morphologies are not fully understood. In this review, we discuss how microglia morphology is not synonymous with microglia function, however, morphological outcomes can be used to make inferences about microglial function. For a comprehensive examination of the reactive status of a microglial cell, both histological and genetic approaches should be combined. However, the importance of quality immunohistochemistry-based analyses should not be overlooked as they can succinctly answer many research questions.

Sleep, inflammation, and hemodynamics in rodent models of traumatic brain injury.

Traumatic brain injury (TBI) can induce dysregulation of sleep. Sleep disturbances include hypersomnia and hyposomnia, sleep fragmentation, difficulty falling asleep, and altered electroencephalograms. TBI results in inflammation and altered hemodynamics, such as changes in blood brain barrier permeability and cerebral blood flow. Both inflammation and altered hemodynamics, which are known sleep regulators, contribute to sleep impairments post-TBI. TBIs are heterogenous in cause and biomechanics, which leads to different molecular and symptomatic outcomes. Animal models of TBI have been developed to model the heterogeneity of TBIs observed in the clinic. This review discusses the intricate relationship between sleep, inflammation, and hemodynamics in pre-clinical rodent models of TBI.

Blood-Brain Barrier Dysfunction Predicts Microglial Activation After Traumatic Brain Injury in Juvenile Rats.

Traumatic brain injury (TBI) disrupts the blood-brain barrier (BBB), which may exacerbate neuroinflammation post-injury. Few translational studies have examined BBB dysfunction and subsequent neuroinflammation post-TBI in juveniles. We hypothesized that BBB dysfunction positively predicts microglial activation and that vulnerability to BBB dysfunction and associated neuroinflammation are dependent on age at injury. Post-natal day (PND)17 and PND35 rats (n = 56) received midline fluid percussion injury or sham surgery, and immunoglobulin-G (IgG) stain was quantified as a marker of extravasated blood in the brain and BBB dysfunction. We investigated BBB dysfunction and the microglial response in the hippocampus, hypothalamus, and motor cortex relative to age at injury and days post-injury (DPI; 1, 7, and 25). We measured the morphologies of ionized calcium-binding adaptor molecule 1-labeled microglia using cell body area and perimeter, microglial branch number and length, end-points/microglial cell, and number of microglia. Data were analyzed using generalized hierarchical models. In PND17 rats, TBI increased levels of IgG compared to shams. Independent of age at injury, IgG in TBI rats was higher at 1 and 7 DPI, but resolved by 25 DPI. TBI activated microglia (more cells and fewer end-points) in PND35 rats compared to respective shams. Independent of age at injury, TBI induced morphological changes indicative of microglial activation, which resolved by 25 DPI. TBI rats had fewer cells and end-points per cell at 1 and 7 DPI than 25 DPI. Independent of TBI, PND17 rats had larger, more activated microglia than PND35 rats; PND17 TBI rats had larger cell body areas and perimeters than PND35 TBI rats. Importantly, we found support in both ages that IgG quantification predicted microglial activation after TBI. The number of microglia increased with increasing IgG, whereas branch length decreased with increasing IgG, which together indicate microglial activation. Our results suggest that stabilization of the BBB after pediatric TBI may be an important therapeutic strategy to limit neuroinflammation and promote recovery.

Traumatic Brain Injury in Mice Generates Early-Stage Alzheimer's Disease Related Protein Pathology that Correlates with Neurobehavioral Deficits.

Traumatic brain injury (TBI) increases the long-term risk of neurodegenerative diseases, including Alzheimer's disease (AD). Here, we demonstrate that protein variant pathology generated in brain tissue of an experimental TBI mouse model is similar to protein variant pathology observed during early stages of AD, and that subacute accumulation of AD associated variants of amyloid beta (Aß) and tau in the TBI mouse model correlated with behavioral deficits. Male C57BL/6 mice were subjected to midline fluid percussion injury or to sham injury, after which sensorimotor function (rotarod, neurological severity score), cognitive deficit (novel object recognition), and affective deficits (elevated plus maze, forced swim task) were assessed post-injury (DPI). Protein pathology at 7, 14, and 28 DPI was measured in multiple brain regions using an immunostain panel of reagents selectively targeting different neurodegenerative disease-related variants of Aß, tau, TDP-43, and alpha-synuclein. Overall, TBI resulted in sensorimotor deficits and accumulation of AD-related protein variant pathology near the impact site, both of which returned to sham levels by 14 DPI. Individual mice, however, showed persistent behavioral deficits and/or accumulation of toxic protein variants at 28 DPI. Behavioral outcomes of each mouse were correlated with levels of seven different protein variants in ten brain regions at specific DPI. Out of 21 significant correlations between protein variant levels and behavioral deficits, 18 were with variants of Aß or tau. Correlations at 28 DPI were all between a single Aß or tau variant, both of which are strongly associated with human AD cases. These data provide a direct mechanistic link between protein pathology resulting from TBI and the hallmarks of AD.

The carbon footprint of different modes of birth in the UK and the Netherlands: An exploratory study using life cycle assessment.

OBJECTIVE: To compare the carbon footprint of caesarean and vaginal birth. DESIGN: Life cycle assessment (LCA). SETTING: Tertiary maternity units and home births in the UK and the Netherlands. POPULATION: Birthing women. METHODS: A cradle-to-grave LCA using openLCA software to model the carbon footprint of different modes of delivery in the UK and the Netherlands. MAIN OUTCOME MEASURES: 'Carbon footprint' (in kgCO2 equivalents [kgCO2 e]). RESULTS: Excluding analgesia, the carbon footprint of a caesarean birth in the UK was 31.21 kgCO2 e, compared with 12.47 kgCO2 e for vaginal birth in hospital and 7.63 kgCO2 e at home. In the Netherlands the carbon footprint of a caesarean was higher (32.96 kgCO2 e), but lower for vaginal birth in hospital and home (10.74 and 6.27 kgCO2 e, respectively). Emissions associated with analgesia for vaginal birth ranged from 0.08 kgCO2 e (with opioid analgesia) to 237.33 kgCO2 e (nitrous oxide with oxygen). Differences in analgesia use resulted in a lower average carbon footprint for vaginal birth in the Netherlands than the UK (11.64 versus 193.26 kgCO2 e). CONCLUSION: The carbon footprint of a caesarean is higher than for a vaginal birth if analgesia is excluded, but this is very sensitive to the analgesia used; use of nitrous oxide with oxygen multiplies the carbon footprint of vaginal birth 25-fold. Alternative methods of pain relief or nitrous oxide destruction systems would lead to a substantial improvement in carbon footprint. Although clinical need and maternal choice are paramount, protocols should consider the environmental impact of different choices.

Diffuse traumatic brain injury substantially alters plasma growth hormone in the juvenile rat.

Traumatic brain injury (TBI) can damage the hypothalamus and cause improper activation of the growth hormone (GH) axis, leading to growth hormone deficiency (GHD). GHD is one of the most prevalent endocrinopathies following TBI in adults; however, the extent to which GHD affects juveniles remains understudied. We used postnatal day 17 rats (n = 83), which model the late infantile/toddler period, and assessed body weights, GH levels, and number of hypothalamic somatostatin neurons at acute (1, 7 days post injury (DPI)) and chronic (18, 25, 43 DPI) time points. We hypothesized that diffuse TBI would alter circulating GH levels because of damage to the hypothalamus, specifically somatostatin neurons. Data were analyzed with generalized linear and mixed effects models with fixed effects interactions between the injury and time. Despite similar growth rates over time with age, TBI rats weighed less than shams at 18 DPI (postnatal day 35; P = 0.03, standardized effect size [d] = 1.24), which is around the onset of puberty. Compared to shams, GH levels were lower in the TBI group during the acute period (P = 0.196; d = 12.3) but higher in the TBI group during the chronic period (P = 0.10; d = 52.1). Although not statistically significant, TBI-induced differences in GH had large standardized effect sizes, indicating biological significance. The mean number of hypothalamic somatostatin neurons (an inhibitor of GH) positively predicted GH levels in the hypothalamus but did not predict GH levels in the somatosensory cortex. Understanding TBI-induced alterations in the GH axis may identify therapeutic targets to improve the quality of life of pediatric survivors of TBI.

Postpartum haemorrhage occurring in UK midwifery units: A national population-based case-control study to investigate incidence, risk factors and outcomes.

OBJECTIVES: To estimate the incidence of, and investigate risk factors for, postpartum haemorrhage (PPH) requiring transfer to obstetric care following birth in midwifery units (MU) in the UK; to describe outcomes for women who experience PPH requiring transfer to obstetric care. METHODS: We conducted a national population-based case-control study in all MUs in the UK using the UK Midwifery Study System (UKMidSS). Between September 2019 and February 2020, 1501 women with PPH requiring transfer to obstetric care following birth in an MU, and 1475 control women were identified. We used multivariable logistic regression, generating adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to investigate risk factors for PPH requiring transfer to obstetric care. RESULTS: The incidence of PPH requiring transfer to obstetric care following birth in an MU was 3.7% (95% CI 3.6%-3.9%). Factors independently associated with PPH requiring transfer to obstetric care were smoking during pregnancy (aOR = 0.73; 95% CI 0.56-0.94), nulliparity (aOR = 1.96; 95% CI 1.66-2.30), previous PPH (aOR = 2.67; 95% CI 1.67-4.25), complications in a previous pregnancy other than PPH (aOR = 2.40; 95% CI 1.25-4.60), gestational age ≥41 weeks (aOR = 1.36; 95% CI 1.10-1.69), instrumental birth (aOR = 2.69; 95% CI 1.53-4.72), third stage of labour ≥60 minutes (aOR = 5.56; 95% CI 3.93-7.88), perineal trauma (aOR = 4.67; 95% CI 3.16-6.90), and birthweight 3500-3999g (aOR = 1.71; 95% CI 1.42-2.07) or ≥4000g (aOR = 2.31; 95% CI 1.78-3.00). One in ten (10.6%) cases received a blood transfusion and one in five (21.0%) were admitted to higher level care. CONCLUSIONS: The risk factors identified in this study align with those identified in previous research and with current guidelines for women planning birth in an MU in the UK. Maternal outcomes after PPH were broadly reassuring and indicative of appropriate management. NHS organisations should ensure that robust guidelines are in place to support management of PPH in MUs.

Primary postpartum haemorrhage and longer-term physical, psychological, and psychosocial health outcomes for women and their partners in high income countries: A mixed-methods systematic review.

OBJECTIVES: Most research about outcomes following postpartum haemorrhage (PPH) has focused on immediate outcomes. There are fewer studies investigating longer-term maternal morbidity following PPH, resulting in a significant knowledge gap. This review aimed to synthesize the evidence about the longer-term physical and psychological consequences of primary PPH for women and their partners from high income settings. METHODS: The review was registered with PROSPERO and five electronic databases were searched. Studies were independently screened against the eligibility criteria by two reviewers and data were extracted from both quantitative and qualitative studies that reported non-immediate health outcomes of primary PPH. RESULTS: Data were included from 24 studies, of which 16 were quantitative, five were qualitative and three used mixed-methods. The included studies were of mixed methodological quality. Of the nine studies reporting outcomes beyond five years after birth, only two quantitative studies and one qualitative study had a follow-up period longer than ten years. Seven studies reported outcomes or experiences for partners. The evidence indicated that women with PPH were more likely to have persistent physical and psychological health problems after birth compared with women who did not have a PPH. These problems, including PTSD symptoms and cardiovascular disease, may be severe and extend for many years after birth and were more pronounced after a severe PPH, as indicated by a blood transfusion or hysterectomy. There was limited evidence about outcomes for partners after PPH, but conflicting evidence of association between PTSD and PPH among partners who witnessed PPH. CONCLUSION: This review explored existing evidence about longer-term physical and psychological health outcomes among women who had a primary PPH in high income countries, and their partners. While the evidence about health outcomes beyond five years after PPH is limited, our findings indicate that women can experience long lasting negative impacts after primary PPH, including PTSD symptoms and cardiovascular disease, extending for many years after birth. PROSPERO REGISTRATION: PROSPERO registration number: CRD42020161144.

Traumatic brain injury in mice generates early-stage Alzheimer's disease related protein pathology that correlates with neurobehavioral deficits.

Traumatic brain injury (TBI) increases the long-term risk of neurodegenerative diseases, including Alzheimer's disease (AD). Here, we demonstrate that protein variant pathology generated in brain tissue of an experimental TBI mouse model is similar to protein variant pathology observed in human ADbrains, and that subacute accumulation of two AD associated variants of amyloid beta (Aß) and tau in the TBI mouse model correlated with behavioral deficits. Male C57BL/6 mice were subjected to midline fluid percussion injury or to sham injury, after which sensorimotor function (rotarod, neurological severity score), cognitive deficit (novel object recognition), and affective deficits (elevated plus maze, forced swim task) were assessed at different days post-injury (DPI). Protein pathology at 7, 14, and 28 DPI was measured in multiple brain regions using an immunostain panel of reagents selectively targeting different neurodegenerative disease-related variants of Aß, tau, TDP-43, and alpha-synuclein. Overall, TBI resulted in sensorimotor deficits and accumulation of AD-related protein variant pathology near the impact site, both of which returned to sham levels by 14 DPI. Individual mice, however, showed persistent behavioral deficits and/or accumulation of selected toxic protein variants at 28 DPI. Behavioral outcomes of each mouse were correlated with levels of seven different protein variants in ten brain regions at specific DPI. Out of 21 significant correlations between protein variant levels and behavioral deficits, 18 were with variants of Aß or tau. Correlations at 28 DPI were all between a single Aß or tau variant, both of which are strongly associated with human AD cases. These data provide a direct mechanistic link between protein pathology resulting from TBI and the hallmarks of AD.

Colony-Stimulating Factor-1 Receptor Inhibition Transiently Attenuated the Peripheral Immune Response to Experimental Traumatic Brain Injury.

To investigate microglial mechanisms in central and peripheral inflammation after experimental traumatic brain injury (TBI), we inhibited the colony-stimulating factor-1 receptor (CSF-1R) with PLX5622 (PLX). We hypothesized that microglia depletion would attenuate central inflammation acutely with no effect on peripheral inflammation. After randomization, male mice (n = 105) were fed PLX or control diets (21 days) and then received midline fluid percussion injury or sham injury. Brain and blood were collected at 1, 3, or 7 days post-injury (DPI). Immune cell populations were quantified in the brain and blood by flow cytometry. Cytokines (interleukin [IL]-6, IL-1ß, tumor necrosis factor-α, interferon-γ, IL-17A, and IL-10) were quantified in the blood using a multi-plex enzyme-linked immunosorbent assay. Data were analyzed using Bayesian multi-variate, multi-level models. PLX depleted microglia at all time points and reduced neutrophils in the brain at 7 DPI. PLX also depleted CD115+ monocytes, reduced myeloid cells, neutrophils, and Ly6Clow monocytes in blood, and elevated IL-6. TBI induced a central and peripheral immune response. TBI elevated leukocytes, microglia, and macrophages in the brain and elevated peripheral myeloid cells, neutrophils, Ly6Cint monocytes, and IL-1ß in the blood. TBI lowered peripheral CD115+ and Ly6Clow monocytes in the blood. TBI PLX mice had fewer leukocytes and microglia in the brain at 1 DPI, with elevated neutrophils at 7 DPI compared to TBI mice on a control diet. TBI PLX mice also had fewer peripheral myeloid cells, CD115+, and Ly6Clow monocytes in the blood at 3 DPI, but elevated Ly6Chigh, Ly6Cint, and CD115+ monocyte populations at 7 DPI, compared to TBI mice on a control diet. TBI PLX mice had elevated proinflammatory cytokines and lower anti-inflammatory cytokines in the blood at 7 DPI compared to TBI mice on a control diet. CSF-1R inhibition reduced the immune response to TBI at 1 and 3 DPI, but elevated peripheral inflammation at 7 DPI.

The natural pattern of birth timing and gestational age in the U.S. compared to England, and the Netherlands.

OBJECTIVE: To examine cross-national differences in gestational age over time in the U.S. and across three wealthy countries in 2020 as well as examine patterns of birth timing by hour of the day in home and spontaneous vaginal hospital births in the three countries. METHODS: We did a comparative cohort analysis with data on gestational age and the timing of birth from the United States, England and the Netherlands, comparing hospital and home births. For overall gestational age comparisons, we drew on national birth cohorts from the U.S. (1990, 2014 & 2020), the Netherlands (2014 & 2020) and England (2020). Birth timing data was drawn from national data from the U.S. (2014 & 2020), the Netherlands (2014) and from a large representative sample from England (2008-10). We compared timing of births by hour of the day in hospital and home births in all three countries. RESULTS: The U.S. overall mean gestational age distribution, based on last menstrual period, decreased by more than half a week between 1990 (39.1 weeks) and 2020 (38.5 weeks). The 2020 U.S. gestational age distribution (76% births prior to 40 weeks) was distinct from England (60%) and the Netherlands (56%). The gestational age distribution and timing of home births was comparable in the three countries. Home births peaked in early morning between 2:00 am and 5:00 am. In England and the Netherlands, hospital spontaneous vaginal births showed a generally similar timing pattern to home births. In the U.S., the pattern was reversed with a prolonged peak of spontaneous vaginal hospital births between 8:00 am to 5:00 pm. CONCLUSIONS: The findings suggest organizational priorities can potentially disturb natural patterns of gestation and birth timing with a potential to improve U.S. perinatal outcomes with organizational models that more closely resemble those of England and the Netherlands.

Outcomes for women admitted for labour care to alongside midwifery units in the UK following a postpartum haemorrhage in a previous pregnancy: A national population-based cohort and nested case-control study using the UK Midwifery Study System (UKMidSS).

BACKGROUND: Women who have experienced a postpartum haemorrhage (PPH) 'requiring treatment or transfusion' are typically advised to plan birth in obstetric-led settings in subsequent pregnancies. Many UK alongside midwifery units (AMU) admit women for labour care following a previous PPH. We aimed to describe outcomes in women admitted for labour care to AMUs following a previous PPH, compare outcomes with other multiparous women admitted to the same AMUs, and explore risk factors for recurrence. METHODS: A national cohort and nested case-control study using the UK Midwifery Study System (UKMidSS), between August 2018 and April 2019. Multivariable Poisson regression and logistic regression were performed to compare outcomes and investigate risk factors for recurrence. FINDINGS: Women who experienced a previous PPH were significantly more likely than comparison women to: have a PPH requiring transfer to obstetric care (4·2% vs. 2·4%, aRR=1·65, 95% CI 1·14-2·38), be transferred to obstetric care for any reason (17·8% vs 11·9%; aRR=1·41; 95% CI 1·09-1·83), and have any PPH≥ 500 ml (22·7% vs 11·1%, aRR=1·86, 95% CI 1·49-2·32). Among women with a previous PPH, previous blood loss > 1500 ml; uterotonics for previous PPH; Caesarean associated with previous PPH; gestation at admission and higher birthweight were independent risk factors for PPH. CONCLUSION: Women considering birth in an AMU after a previous PPH should be advised that they are at increased risk of experiencing a subsequent PPH requiring transfer to obstetric care, compared with other multiparous women who have not had a PPH. The absolute risk of a subsequent PPH in this group is low and comparable to the overall risk of having a PPH among women having a spontaneous vaginal birth in England.

Reactive morphology of dividing microglia following kainic acid administration.

The microglial response to a pathological microenvironment is hallmarked by a change in cellular morphology. Following a pathological stimulus, microglia become reactive and simultaneously divide to create daughter cells. Although a wide array of microglial morphologies has been observed, the exact functions of these distinct morphologies are unknown, as are the morphology and reactivity status of dividing microglia. In this study, we used kainic acid to trigger microglial activation and cell division. Following a cortical kainic acid injection, microglial morphology and proliferation were examined at 3 days post-injection using immunohistochemistry for ionized calcium binding adapter molecule 1 (Iba1) to stain for microglia, and KI67 as a marker of cell division. Individual microglial cells were isolated from photomicrographs and skeletal and fractal analyses were used to examine cell size and spatial complexity. We examined the morphology of microglia in both wildtype and microglia-specific tumor necrosis factor (TNF)-α knockout mice. Data were analyzed using generalized linear mixed models or a two-way ANOVA. We found that dividing microglia had a more reactive morphology (larger cell body area, longer cell perimeter, and less ramification) compared to microglia that were not dividing, regardless of microglial release of TNF-α. However, we also observed dividing microglia with a complex, more ramified morphology. Changes in microglial morphology and division were greatest near the kainic acid injection site. This study uses robust and quantitative techniques to better understand microglial cell division, morphology, and population dynamics, which are essential for the development of novel therapeutics that target microglia.

Comparisons of quantitative approaches for assessing microglial morphology reveal inconsistencies, ecological fallacy, and a need for standardization.

Microglial morphology is used to measure neuroinflammation and pathology. For reliable inference, it is critical that microglial morphology is accurately quantified and that results can be easily interpreted and compared across studies and laboratories. The process through which microglial morphology is quantified is a key methodological choice and little is known about how this choice may bias conclusions. We applied five of the most commonly used ImageJ-based methods for quantifying the microglial morphological response to a stimulus to identical photomicrographs and individual microglial cells isolated from these photomicrographs, which allowed for direct comparisons of results generated using these approaches. We found a lack of comparability across methods that analyzed full photomicrographs, with significant discrepancies in results among the five methods. Quantitative methods to analyze microglial morphology should be selected based on several criteria, and combinations of these methods may give the most biologically accurate representation of microglial morphology.