Mechanical disruption of the blood-brain barrier following experimental concussion

Although concussion is now recognized as a major health issue, its non-lethal nature has limited characterization of the underlying pathophysiology. In particular, potential neuropathological changes have typically been inferred from non-invasive techniques or post-mortem examinations of severe traumatic brain injury (TBI). Here, we used a swine model of head rotational acceleration based on human concussion to examine blood–brain barrier (BBB) integrity after injury in association with diffuse axonal injury and glial responses. We then determined the potential clinical relevance of the swine concussion findings through comparisons with pathological changes in human severe TBI, where post-mortem examinations are possible. At 6–72 h post-injury in swine, we observed multifocal disruption of the BBB, demonstrated by extravasation of serum proteins, fibrinogen and immunoglobulin-G, in the absence of hemorrhage or other focal pathology. BBB disruption was observed in a stereotyped distribution consistent with biomechanical insult. Specifically, extravasated serum proteins were frequently observed at interfaces between regions of tissue with differing material properties, including the gray–white boundary, periventricular and subpial regions. In addition, there was substantial overlap of BBB disruption with regions of axonal pathology in the white matter. Acute perivascular cellular uptake of blood-borne proteins was observed to be prominent in astrocytes (GFAP-positive) and neurons (MAP-2-positive), but not microglia (IBA1-positive). Parallel examination of human severe TBI revealed similar patterns of serum extravasation and glial uptake of serum proteins, but to a much greater extent than in the swine model, attributed to the higher injury severity. These data suggest that BBB disruption represents a new and important pathological feature of concussion

Population-Based Linked Longitudinal Surveillance of Pregnant People and Their Infants: A Critical Resource for Emerging, Re-Emerging, and Persistent Threats

Public health emergencies, from Zika to COVID-19, have underscored the importance of addressing the needs of pregnant people and their infants. Recent events have underlined the critical role of mother-infant-linked longitudinal surveillance to characterize and assess the impacts of emerging, re-emerging, and persistent threats, including infectious diseases, on these populations. In partnership with state, local, and territorial health departments, CDC\u27s National Center on Birth Defects and Developmental Disabilities activated the Surveillance for Emerging Threats to Mothers and Babies Network (SET-NET) to capture information about pregnant people with laboratory-confirmed infection with SARS-CoV-2 (the virus that causes COVID-19) and their infants. SET-NET data were critical in recognizing the severe risks of COVID-19 during pregnancy, which ultimately informed clinical decisions and public health policy, specifically vaccine prioritization at the local, state, and national levels. This commentary describes the activation of SET-NET to monitor COVID-19 in pregnancy and highlights the experiences of health departments. We provide examples of how SET-NET findings informed COVID-19 prevention efforts and public health policy. Lastly, we identify opportunities to improve and advance surveillance efforts to protect the health of pregnant people and their infants in the United States from current and future threats

An Anglo-Saxon execution cemetery at Walkington Wold, Yorkshire

This paper presents a re-evaluation of a cemetery excavated over 30 years ago at Walkington Wold in east Yorkshire. The cemetery is characterized by careless burial on diverse alignments, and by the fact that most of the skeletons did not have associated crania. The cemetery has been variously described as being the result of an early post-Roman massacre, as providing evidence for a ‘Celtic’ head cult or as an Anglo-Saxon execution cemetery. In order to resolve the matter, radiocarbon dates were acquired and a re-examination of the skeletal remains was undertaken. It was confirmed that the cemetery was an Anglo-Saxon execution cemetery, the only known example from northern England, and the site is set into its wider context in the paper

Promoter-Wide Hypermethylation of the Ribosomal RNA Gene Promoter in the Suicide Brain

BACKGROUND: Alterations in gene expression in the suicide brain have been reported and for several genes DNA methylation as an epigenetic regulator is thought to play a role. rRNA genes, that encode ribosomal RNA, are the backbone of the protein synthesis machinery and levels of rRNA gene promoter methylation determine rRNA transcription. METHODOLOGY/PRINCIPAL FINDINGS: We test here by sodium bisulfite mapping of the rRNA promoter and quantitative real-time PCR of rRNA expression the hypothesis that epigenetic differences in critical loci in the brain are involved in the pathophysiology of suicide. Suicide subjects in this study were selected for a history of early childhood neglect/abuse, which is associated with decreased hippocampal volume and cognitive impairments. rRNA was significantly hypermethylated throughout the promoter and 5' regulatory region in the brain of suicide subjects, consistent with reduced rRNA expression in the hippocampus. This difference in rRNA methylation was not evident in the cerebellum and occurred in the absence of genome-wide changes in methylation, as assessed by nearest neighbor. CONCLUSIONS/SIGNIFICANCE: This is the first study to show aberrant regulation of the protein synthesis machinery in the suicide brain. The data implicate the epigenetic modulation of rRNA in the pathophysiology of suicide

Museum epigenomics: Characterizing cytosine methylation in historic museum specimens

Museum genomics has transformed the field of collections‐based research, opening up a range of new research directions for paleontological specimens as well as natural history specimens collected over the past few centuries. Recent work demonstrates that it is possible to characterize epigenetic markers such as DNA methylation in well preserved ancient tissues. This approach has not yet been tested in traditionally prepared natural history specimens such as dried bones and skins, the most common specimen types in vertebrate collections. In this study, we developed and tested methods to characterize cytosine methylation in dried skulls up to 76 years old. Using a combination of ddRAD and bisulphite treatment, we characterized patterns of cytosine methylation in two species of deer mouse (Peromyscus spp.) collected in the same region in Michigan in 1940, 2003, and 2013–2016. We successfully estimated methylation in specimens of all age groups, although older specimens yielded less data and showed greater interindividual variation in data yield than newer specimens. Global methylation estimates were reduced in the oldest specimens (76 years old) relative to the newest specimens (1–3 years old), which may reflect post‐mortem hydrolytic deamination. Methylation was reduced in promoter regions relative to gene bodies and showed greater bimodality in autosomes relative to female X chromosomes, consistent with expectations for methylation in mammalian somatic cells. Our work demonstrates the utility of historic specimens for methylation analyses, as with genomic analyses; however, studies will need to accommodate the large variance in the quantity of data produced by older specimens.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162784/5/men13115.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162784/4/men13115-sup-0003-AppendixS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162784/3/men13115-sup-0001-FigS1-S2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162784/2/men13115_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162784/1/men13115-sup-0002-TableS1-S2.pd

Examining the Course of Transitions from Hospital to Home-based Palliative Care: A Mixed Methods Study

Background: Hospital-to-home transitions in palliative care are fraught with challenges. To assess transitions researchers have used patient reported outcome measures and qualitative data to give unique insights into a phenomenon. Few measures examine care setting transitions in palliative care, yet domains identified in other populations are likely relevant for patients receiving palliative care. Aim: Gain insight into how patients experience three domains, discharge readiness, transition quality, and discharge-coping, during hospital-to-home transitions. Design: Longitudinal, convergent parallel mixed methods study design with two data collection visits: in-hospital before and 3–4 weeks after discharge. Participants completed scales assessing discharge readiness, transition quality, and post discharge-coping. A qualitative interview was conducted at both visits. Data were analyzed separately and integrated using a merged transformative methodology, allowing us to compare and contrast the data. Setting and participants: Study was set in two tertiary hospitals in Toronto, Canada. Adult inpatients (n = 25) and their caregivers (n = 14) were eligible if they received a palliative care consultation and transitioned to home-based palliative care. Results: Results were organized aligning with the scales; finding low discharge readiness (5.8; IQR: 1.9), moderate transition quality (66.7; IQR: 33.33), and poor discharge-coping (5.0; IQR: 2.6), respectively. Positive transitions involved feeling well supported, managing medications, feeling well, and having healthcare needs met. Challenges in transitions were feeling unwell, confusion over medications, unclear healthcare responsibilities, and emotional distress. Conclusions: We identified aspects of these three domains that may be targeted to improve transitions through intervention development. Identified discrepancies between the data types should be considered for future research exploration

Cytoplasmic BK\u3csub\u3eCa\u3c/sub\u3e channel intron-containing mRNAs contribute to the intrinsic excitability of hippocampal neurons

High single-channel conductance K+ channels, which respond jointly to membrane depolarization and micromolar concentrations of intracellular Ca2+ ions, arise from extensive cell-specific alternative splicing of pore-forming α-subunit mRNAs. Here, we report the discovery of an endogenous BKCa channel α-subunit intron-containing mRNA in the cytoplasm of hippocampal neurons. This partially processed mRNA, which comprises ≈10% of the total BKCa channel α-subunit mRNAs, is distributed in a gradient throughout the somatodendritic space. We selectively reduced endogenous cytoplasmic levels of this intron-containing transcript by RNA interference without altering levels of the mature splice forms of the BKCa channel mRNAs. In doing so, we could demonstrate that changes in a unique BKCa channel α-subunit introncontaining splice variant mRNA can greatly impact the distribution of the BKCa channel protein to dendritic spines and intrinsic firing properties of hippocampal neurons. These data suggest a new regulatory mechanism for modulating the membrane properties and ion channel gradients of hippocampal neurons

Maternal effects on anogenital distance in a wild marmot population

Peer reviewedPublisher PD

The magnitude of translational and rotational head accelerations experienced by riders during downhill mountain biking

Objectives To determine the magnitude of translational and rotational head accelerations during downhill mountain biking. Design Observational study Methods Sixteen male downhill cyclists (age 26.4 ± 8.4 years; stature 179.4 ± 7.2 cm; mass 75.3 ± 5.9 kg) were monitored during two rounds of the British Downhill Series. Riders performed two runs on each course wearing a triaxial accelerometer behind the right ear. The means of the two runs for each course were used to determine differences between courses for mean and maximum peak translational (g) and rotational accelerations (rads/s2) and impact duration for each course. Results Significant differences (p 10 g), FW = 12.5 ± 7.6, RYF = 42.8 ± 27.4 (t(22.96) = -4.70; p < 0.001; 95 % CI = 17.00 to 43.64); maximum peak rotational acceleration, FW = 6805.4 ± 3073.8 rads/s2, RYF = 9799.9 ± 3381.7 rads/s2 (t(32) = -2.636; p = 0.01; 95 % CI = 680.31 to 5308.38); mean acceleration duration FW = 4.7 ± 1.2 ms, RYF = 6.5 ± 1.4 ms (t(32) = -4.05; p < 0.001; 95 % CI = 0.91 to 2.76) and maximum acceleration duration, FW = 11.6 ± 4.5 ms, RYF = 21.2 ± 9.1 (t(29.51) = -4.06; p = 0.001; 95 % CI = 4.21 to 14.94). No other significant differences were found. Conclusions Findings indicate that downhill riders may be at risk of sustaining traumatic brain injuries and course design influences the number and magnitude of accelerations