Cytoarchitecture of ex vivo midgut cultures of unfed Ixodes scapularis infected with a tick-borne flavivirus

A bite from an infected tick is the primary means of transmission for tick-borne flaviviruses (TBFV). Ticks ingest the virus while feeding on infected blood. The traditional view is that the virus first replicates in and transits the tick midgut prior to dissemination to other organs, including salivary glands. Thus, understanding TBFV infection in the tick midgut is a key first step in identifying potential countermeasures against infection. Ex vivo midgut cultures prepared from unfed adult female Ixodes scapularis ticks were viable and remained morphologically intact for more than 8 days. The midgut consisted of two clearly defined cell layers separated by a basement membrane: an exterior network of smooth muscle cells and an internal epithelium composed of digestive generative cells. The smooth muscle cells were arranged in a stellate circumferential pattern spaced at regular intervals along the long axis of midgut diverticula. When the cultures were infected with the TBFV Langat virus (LGTV), virus production increased by two logs with a peak at 96 hours post-infection. Infected cells were readily identified by immunofluorescence staining for the viral envelope protein, nonstructural protein 3 (NS3) and dsRNA. Microscopy of the stained cultures suggested that generative cells were the primary target for virus infection in the midgut. Infected cells exhibited an expansion of membranes derived from the endoplasmic reticulum; a finding consistent with TBFV infected cell cultures. Electron microscopy of infected cultures revealed virus particles in the basolateral region between epithelial cells. These results demonstrated LGTV replication in midgut generative cells of artificially infected, ex vivo cultures of unfed adult female I. scapularis ticks.

Skin muscle is the initial site of viral replication for arboviral bunyavirus infection

The first step in disease pathogenesis for arboviruses is the establishment of infection following vector transmission. For La Crosse virus (LACV), the leading cause of pediatric arboviral encephalitis in North America, and other orthobunyaviruses, the initial course of infection in the skin is not well understood. Using an intradermal (ID) model of LACV infection in mice, we find that the virus infects and replicates nearly exclusively within skin-associated muscle cells of the panniculus carnosus (PC) and not in epidermal or dermal cells like most other arbovirus families. LACV is widely myotropic, infecting distal muscle cells of the peritoneum and heart, with limited infection of draining lymph nodes. Surprisingly, muscle cells are resistant to virus-induced cell death, with long term low levels of virus release progressing through the Golgi apparatus. Thus, skin muscle may be a key cell type for the initial infection and spread of arboviral orthobunyaviruses.

Plasma SOMAmer proteomics of postoperative delirium

BACKGROUND

Postoperative delirium is prevalent in older adults and has been shown to increase the risk of long-term cognitive decline. Plasma biomarkers to identify the risk for postoperative delirium and the risk of Alzheimer's disease and related dementias are needed.

METHODS

This biomarker discovery case-control study aimed to identify plasma biomarkers associated with postoperative delirium. Patients aged ≥65 years undergoing major elective noncardiac surgery were recruited. The preoperative plasma proteome was interrogated with SOMAmer-based technology targeting 1433 biomarkers.

RESULTS

In 40 patients (20 with vs. 20 without postoperative delirium), a preoperative panel of 12 biomarkers discriminated patients with postoperative delirium with an accuracy of 97.5%. The final model of five biomarkers delivered a leave-one-out cross-validation accuracy of 80%. Represented biological pathways included lysosomal and immune response functions.

CONCLUSION

In older patients who have undergone major surgery, plasma SOMAmer proteomics may provide a relatively non-invasive benchmark to identify biomarkers associated with postoperative delirium.

Early immune factors associated with the development of post-acute sequelae of SARS-CoV-2 infection in hospitalized and non-hospitalized individuals

Background

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to post-acute sequelae of SARS-CoV-2 (PASC) that can persist for weeks to years following initial viral infection. Clinical manifestations of PASC are heterogeneous and often involve multiple organs. While many hypotheses have been made on the mechanisms of PASC and its associated symptoms, the acute biological drivers of PASC are still unknown.

Methods

We enrolled 494 patients with COVID-19 at their initial presentation to a hospital or clinic and followed them longitudinally to determine their development of PASC. From 341 patients, we conducted multi-omic profiling on peripheral blood samples collected shortly after study enrollment to investigate early immune signatures associated with the development of PASC.

Results

During the first week of COVID-19, we observed a large number of differences in the immune profile of individuals who were hospitalized for COVID-19 compared to those individuals with COVID-19 who were not hospitalized. Differences between individuals who did or did not later develop PASC were, in comparison, more limited, but included significant differences in autoantibodies and in epigenetic and transcriptional signatures in double-negative 1 B cells, in particular.

Conclusions

We found that early immune indicators of incident PASC were nuanced, with significant molecular signals manifesting predominantly in double-negative B cells, compared with the robust differences associated with hospitalization during acute COVID-19. The emerging acute differences in B cell phenotypes, especially in double-negative 1 B cells, in PASC patients highlight a potentially important role of these cells in the development of PASC.

Assessing patterns of delirium symptoms reveals a novel subtype among elective surgical patients with postoperative delirium

OBJECTIVES

Prior studies reported incidence of hypoactive and hyperactive subtypes of postoperative delirium, but did not consider cognitive symptoms of delirium which are highlighted in the DSM-5 criteria for delirium. This study aims to address this gap in the literature by classifying cases of delirium according to their constellation of cognitive and motoric symptoms of delirium using a statistical technique called Latent Class Analysis (LCA).

METHODS

Data were from five independent study cohorts (N = 1968) of patients who underwent elective spine, knee/hip, or elective gastrointestinal and thoracic procedures, between 2001 and 2017. Assessments of delirium symptoms were conducted using the long form of the Confusion Assessment Method (CAM) pre- and post-surgery. Latent class analyses of CAM data from the first 2 days after surgery were conducted to determine subtypes of delirium based on patterns of cognitive and motoric symptoms of delirium. We also determined perioperative patient characteristics associated with each latent class of delirium and assessed whether the length of delirium for each of the patterns of delirium symptoms identified by the latent class analysis.

RESULTS

The latent class model from postoperative day 1 revealed three distinct patterns of delirium symptoms. One pattern of symptoms, denoted as the Hyperalert class, included patients whose predominant symptoms were being hyperalert or overly sensitive to environmental stimuli and having a low level of motor activity. Another pattern of symptoms, denoted as the Hypoalert class, included patients whose predominant symptom was being hypoalert (lethargic or drowsy). A third pattern of symptoms, denoted as the Cognitive Changes class, included patients who experienced new onset of disorganized thinking, memory impairment, and disorientation. Among 352 patients who met CAM criteria for delirium on postoperative day 1, 34% had symptoms that fit within the Hyperalert latent class, 39% had symptoms that fit within the Hypoalert latent class, and 27% had symptoms that fit within the Cognitive Changes latent class. Similar findings were found when latent class analysis was applied to those who met CAM criteria for delirium on postoperative day 2. Multinomial regression analyses revealed that ASA class, surgery type, and preoperative cognitive status as measured by the Telephone Interview for Cognitive Status (TICS) scores were associated with class membership. Length of delirium differed between the latent classes with the Cognitive Changes latent class having a longer duration compared to the other two classes.

CONCLUSIONS

Older elective surgery patients who did not have acute events or illnesses or a diagnosis of dementia prior to surgery displayed varying symptoms of delirium after surgery. Compared to prior studies that described hypoactive and hyperactive subtypes of delirium, we identified a novel subtype of delirium that reflects cognitive symptoms of delirium. The three subtypes of delirium reveal distinct patterns of delirium symptoms which provide insight into varying risks and care needs of patients with delirium, indicating the necessity of future research on reducing risk for cognitive symptoms of delirium.

Multi-omic profiling reveals early immunological indicators for identifying COVID-19 Progressors

We sought to better understand the immune response during the immediate post-diagnosis phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by identifying molecular associations with longitudinal disease outcomes. Multi-omic analyses identified differences in immune cell composition, cytokine levels, and cell subset-specific transcriptomic and epigenomic signatures between individuals on a more serious disease trajectory (Progressors) as compared to those on a milder course (Non-progressors). Higher levels of multiple cytokines were observed in Progressors, with IL-6 showing the largest difference. Blood monocyte cell subsets were also skewed, showing a comparative decrease in non-classical CD14-CD16+ and intermediate CD14+CD16+ monocytes. In lymphocytes, the CD8+ T effector memory cells displayed a gene expression signature consistent with stronger T cell activation in Progressors. These early stage observations could serve as the basis for the development of prognostic biomarkers of disease risk and interventional strategies to improve the management of severe COVID-19. BACKGROUND: Much of the literature on immune response post-SARS-CoV-2 infection has been in the acute and post-acute phases of infection. TRANSLATIONAL SIGNIFICANCE: We found differences at early time points of infection in approximately 160 participants. We compared multi-omic signatures in immune cells between individuals progressing to needing more significant medical intervention and non-progressors. We observed widespread evidence of a state of increased inflammation associated with progression, supported by a range of epigenomic, transcriptomic, and proteomic signatures. The signatures we identified support other findings at later time points and serve as the basis for prognostic biomarker development or to inform interventional strategies.

Fine structure and molecular characterization of two new parabasalid species that naturally colonize laboratory mice, Tritrichomonas musculus and Tritrichomonas casperi

Tritrichomonas muris is a common flagellated protist isolated from the cecum of wild rodents. This commensal protist has been shown previously to alter immune phenotypes in laboratory mice. Other trichomonads, referred to as Tritrichomonas musculis and Tritrichomonas rainier, also naturally colonize laboratory mice and cause immune alterations. This report formally describes two new trichomonads, Tritrichomonas musculus n. sp., and Tritrichomonas casperi n. sp., at the ultrastructural and molecular level. These two protists were isolated from laboratory mice and were differentiated by their size and the structure of their undulating membrane and posterior flagellum. Analysis at the 18S rRNA and trans-ITS genetic loci supported their designation as distinct species, related to T. muris. To assess the true extent of parabasalid diversity infecting laboratory mice, 135 mice bred at the National Institutes of Health (NIH) were screened using pan-parabasalid primers that amplify the trans-ITS region. Forty-four percent of mice were positive for parabasalids, encompassing a total of eight distinct sequence types. Tritrichomonas casperi and Trichomitus-like protists were dominant. T. musculus and T. rainier were also detected, but T. muris was not. Our work establishes a previously underappreciated diversity of commensal trichomonad flagellates that naturally colonize the enteric cavity of laboratory mice.

Distinct temporal trajectories and risk factors for Post-acute sequelae of SARS-CoV-2 infection

Background

The understanding of Post-acute sequelae of SARS-CoV-2 infection (PASC) can be improved by longitudinal assessment of symptoms encompassing the acute illness period. To gain insight into the various disease trajectories of PASC, we assessed symptom evolution and clinical factors associated with the development of PASC over 3 months, starting with the acute illness period.

Methods

We conducted a prospective cohort study to identify parameters associated with PASC. We performed cluster and case control analyses of clinical data, including symptomatology collected over 3 months following infection.

Results

We identified three phenotypic clusters associated with PASC that could be characterized as remittent, persistent, or incident based on the 3-month change in symptom number compared to study entry: remittent (median; min, max: -4; -17, 3), persistent (-2; -14, 7), or incident (4.5; -5, 17) (p = 0.041 remittent vs. persistent, p < 0.001 remittent vs. incident, p < 0.001 persistent vs. incident). Despite younger age and lower hospitalization rates, the incident phenotype had a greater number of symptoms (15; 8, 24) and a higher proportion of participants with PASC (63.2%) than the persistent (6; 2, 9 and 52.2%) or remittent clusters (1; 0, 6 and 18.7%). Systemic corticosteroid administration during acute infection was also associated with PASC at 3 months [OR (95% CI): 2.23 (1.14, 4.36)].

Conclusion

An incident disease phenotype characterized by symptoms that were absent during acute illness and the observed association with high dose steroids during acute illness have potential critical implications for preventing PASC.

Presence of Preoperative Neurodegeneration Biofluid Markers in Patients with Postoperative Delirium

BACKGROUND

The pathophysiology of delirium is incompletely understood, including what molecular pathways are involved in brain vulnerability to delirium. This study examined whether preoperative plasma neurodegeneration markers were elevated in patients who subsequently developed postoperative delirium through a retrospective case-control study.

METHODS

Inclusion criteria were patients of 65 yr of age or older, undergoing elective noncardiac surgery with a hospital stay of 2 days or more. Concentrations of preoperative plasma P-Tau181, neurofilament light chain, amyloid β1-42 (Aβ42), and glial fibrillary acidic protein were measured with a digital immunoassay platform. The primary outcome was postoperative delirium measured by the Confusion Assessment Method. The study included propensity score matching by age and sex with nearest neighbor, such that each patient in the delirium group was matched by age and sex with a patient in the no-delirium group.

RESULTS

The initial cohort consists of 189 patients with no delirium and 102 patients who developed postoperative delirium. Of 291 patients aged 72.5 ± 5.8 yr, 50.5% were women, and 102 (35%) developed postoperative delirium. The final cohort in the analysis consisted of a no-delirium group (n = 102) and a delirium group (n = 102) matched by age and sex using the propensity score method. Of the four biomarkers assayed, the median value for neurofilament light chain was 32.05 pg/ml for the delirium group versus 23.7 pg/ml in the no-delirium group. The distribution of biomarker values significantly differed between the delirium and no-delirium groups (P = 0.02 by the Kolmogorov-Smirnov test) with the largest cumulative probability difference appearing at the biomarker value of 32.05 pg/ml.

CONCLUSIONS

These results suggest that patients who subsequently developed delirium are more likely to be experiencing clinically silent neurodegenerative changes before surgery, reflected by changes in plasma neurofilament light chain biomarker concentrations, which may identify individuals with a preoperative vulnerability to subsequent cognitive decline.

EDITOR’S PERSPECTIVE

N4 -Hydroxycytidine/Molnupiravir Inhibits RNA-Virus Induced Encephalitis by Producing Mutated Viruses with Reduced Fitness

A diverse group of RNA viruses including Rabies, Polio, La Crosse, West Nile, Zika, Nipah, Eastern and Western equine encephalitis, Venezuelan equine encephalitis, Japanese encephalitis, and tick-borne encephalitis viruses have the ability to gain access to and replicate in the central nervous system (CNS), causing severe neurological disease. Current treatment for these patients is generally limited to supportive care. To address the need for a generalizable antiviral, we utilized a strategy of mutagenesis to limit virus replication. We evaluated ribavirin (RBV), favipiravir (FAV) and N 4 -hydroxycytidine (NHC) against La Crosse virus (LACV) which is the primary cause of pediatric arboviral encephalitis cases in North America. NHC was more potent than RBV or FAV in neuronal cells. Oral administration of molnupiravir (MOV), the 5'-isobutyryl prodrug of NHC, decreased neurological disease development by 32% following intraperitoneal (IP) infection of LACV. MOV also reduced disease by 23% when virus was administered intranasally (IN). NHC and MOV produced less fit viruses by incorporating predominantly G-to-A or C-to-U mutations. Furthermore, NHC also inhibited two other orthobunyaviruses, Jamestown Canyon virus and Cache Valley virus. Collectively, these studies indicate that NHC/MOV has therapeutic potential to inhibit virus replication and subsequent neurological disease caused by this neurotropic RNA virus.

Genetically diverse mouse models of SARS-CoV-2 infection reproduce clinical variation in type I interferon and cytokine responses in COVID-19

Inflammation in response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection drives severity of coronavirus disease 2019 (COVID-19) and is influenced by host genetics. To understand mechanisms of inflammation, animal models that reflect genetic diversity and clinical outcomes observed in humans are needed. We report a mouse panel comprising the genetically diverse Collaborative Cross (CC) founder strains crossed to human ACE2 transgenic mice (K18-hACE2) that confers susceptibility to SARS-CoV-2. Infection of CC x K18-hACE2 resulted in a spectrum of survival, viral replication kinetics, and immune profiles. Importantly, in contrast to the K18-hACE2 model, early type I interferon (IFN-I) and regulated proinflammatory responses were required for control of SARS-CoV-2 replication in PWK x K18-hACE2 mice that were highly resistant to disease. Thus, virus dynamics and inflammation observed in COVID-19 can be modeled in diverse mouse strains that provide a genetically tractable platform for understanding anti-coronavirus immunity.

Multi-omic Profiling Reveals Early Immunological Indicators for Identifying COVID-19 Progressors

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a rapid response by the scientific community to further understand and combat its associated pathologic etiology. A focal point has been on the immune responses mounted during the acute and post-acute phases of infection, but the immediate post-diagnosis phase remains relatively understudied. We sought to better understand the immediate post-diagnosis phase by collecting blood from study participants soon after a positive test and identifying molecular associations with longitudinal disease outcomes. Multi-omic analyses identified differences in immune cell composition, cytokine levels, and cell subset-specific transcriptomic and epigenomic signatures between individuals on a more serious disease trajectory (Progressors) as compared to those on a milder course (Non-progressors). Higher levels of multiple cytokines were observed in Progressors, with IL-6 showing the largest difference. Blood monocyte cell subsets were also skewed, showing a comparative decrease in non-classical CD14-CD16+ and intermediate CD14+CD16+ monocytes. Additionally, in the lymphocyte compartment, CD8+ T effector memory cells displayed a gene expression signature consistent with stronger T cell activation in Progressors. Importantly, the identification of these cellular and molecular immune changes occurred at the early stages of COVID-19 disease. These observations could serve as the basis for the development of prognostic biomarkers of disease risk and interventional strategies to improve the management of severe COVID-19.

Sleep Loss the night before surgery and incidence of postoperative delirium in adults 65-95 years of age

STUDY OBJECTIVES

To describe the association between preoperative sleep disruption and postoperative delirium.

METHODS

Prospective cohort study with six time points (3 nights pre-hospitalization and 3 nights post-surgery). The sample included 180 English-speaking patients ≥65 years old scheduled for major non-cardiac surgery and anticipated minimum hospital stay of 3 days. Six days of wrist actigraphy recorded continuous movement to estimate wake and sleep minutes during the night from 22:00 to 05:59. Postoperative delirium was measured by a structured interview using the Confusion Assessment Method. Sleep variables for patients with (n = 32) and without (n = 148) postoperative delirium were compared using multivariate logistic regression.

RESULTS

Participants had a mean age of 72 ± 5 years (range 65-95 years). The incidence of postoperative delirium during any of the three postoperative days was 17.8%. Postoperative delirium was significantly associated with surgery duration (OR = 1.49, 95% CI 1.24-1.83) and sleep loss >15% on the night before surgery (OR = 2.64, 95% CI 1.10-6.62). Preoperative symptoms of pain, anxiety and depression were unrelated to preoperative sleep loss.

CONCLUSIONS

In this study of adults ≥65 years of age, short sleep duration was more severe preoperatively in the patients who experienced postoperative delirium as evidenced by sleep loss >15% of their normal night's sleep. However, we were unable to identify potential reasons for this sleep loss. Further investigation should include additional factors that may be associated with preoperative sleep loss to inform potential intervention strategies to mitigate preoperative sleep loss and reduce risk of postoperative delirium.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

Lidocaine Infusion for the Management of Postoperative Pain and Delirium (LIMPP): protocol for a randomised control trial

INTRODUCTION

Postoperative delirium is a frequent adverse event following elective non-cardiac surgery. The occurrence of delirium increases the risk of functional impairment, placement to facilities other than home after discharge, cognitive impairment at discharge, as well as in-hospital and possibly long-term mortality. Unfortunately, there is a dearth of effective strategies to minimise the risk from modifiable risk factors, including postoperative pain control and the analgesic regimen. Use of potent opioids, currently the backbone of postoperative pain control, alters cognition and has been associated with an increased risk of postoperative delirium. Literature supports the intraoperative use of lidocaine infusions to decrease postoperative opioid requirements, however, whether the use of postoperative lidocaine infusions is associated with lower opioid requirements and subsequently a reduction in postoperative delirium has not been investigated.

METHODS AND ANALYSIS

The Lidocaine Infusion for the Management of Postoperative Pain and Delirium trial is a randomised, double-blinded study of a postoperative 48-hour infusion of lidocaine at 1.33 mg/kg/hour versus placebo in older patients undergoing major reconstructive spinal surgery at the University of California, San Francisco. Our primary outcome is incident delirium measured daily by the Confusion Assessment Method in the first three postoperative days. Secondary outcomes include delirium severity, changes in cognition, pain scores, opioid use, incidence of opioid related side effects and functional benefits including time to discharge and improved recovery from surgery. Lidocaine safety will be assessed with daily screening questionnaires and lidocaine plasma levels.

ETHICS AND DISSEMINATION

This study protocol has been approved by the ethics board at the University of California, San Francisco. The results of this study will be published in a peer-review journal and presented at national conferences as poster or oral presentations. Participants wishing to know the results of this study will be contacted directly on data publication.

TRIAL REGISTRATION NUMBER

NCT05010148.

A pigtailed macaque model of Kyasanur Forest disease virus and Alkhurma hemorrhagic disease virus pathogenesis

Kyasanur Forest disease virus (KFDV) and the closely related Alkhurma hemorrhagic disease virus (AHFV) are emerging flaviviruses that cause severe viral hemorrhagic fevers in humans. Increasing geographical expansion and case numbers, particularly of KFDV in southwest India, class these viruses as a public health threat. Viral pathogenesis is not well understood and additional vaccines and antivirals are needed to effectively counter the impact of these viruses. However, current animal models of KFDV pathogenesis do not accurately reproduce viral tissue tropism or clinical outcomes observed in humans. Here, we show that pigtailed macaques (Macaca nemestrina) infected with KFDV or AHFV develop viremia that peaks 2 to 4 days following inoculation. Over the course of infection, animals developed lymphocytopenia, thrombocytopenia, and elevated liver enzymes. Infected animals exhibited hallmark signs of human disease characterized by a flushed appearance, piloerection, dehydration, loss of appetite, weakness, and hemorrhagic signs including epistaxis. Virus was commonly present in the gastrointestinal tract, consistent with human disease caused by KFDV and AHFV where gastrointestinal symptoms (hemorrhage, vomiting, diarrhea) are common. Importantly, RNAseq of whole blood revealed that KFDV downregulated gene expression of key clotting factors that was not observed during AHFV infection, consistent with increased severity of KFDV disease observed in this model. This work characterizes a nonhuman primate model for KFDV and AHFV that closely resembles human disease for further utilization in understanding host immunity and development of antiviral countermeasures.

Obesity and perioperative outcomes in older surgical patients undergoing elective spine and major arthroplasty surgery

STUDY OBJECTIVE

To determine whether obesity status is associated with perioperative complications, discharge outcomes and hospital length of stay in older surgical patients.

DESIGN

Secondary analysis of five independent study cohorts (N = 1262).

SETTING

An academic medical center between 2001 and 2017 in the United States.

PATIENTS

Patients aged 65 years or older who were scheduled to undergo elective spine, knee, or hip surgery with an expected hospital stay of at least 2 days.

MEASUREMENTS

Body mass index (BMI) was stratified as nonobese (BMI ≤ 30 kg/m2), obesity class 1 (30 kg/m2 ≤ BMI < 35 kg/m2) or obesity class 2-3 (BMI ≥ 35 kg/m2). Primary outcomes included predefined intraoperative and postoperative complications, hospital length of stay (LOS), and discharge location. Univariate and multivariate logistic regression was performed.

MAIN RESULTS

Obesity status was not associated with intraoperative adverse events. However, obesity class 2-3 significantly increased the risk for postoperative complications (IRR 1.43, 95% CI 1.03-1.95, P = 0.03), hospital LOS (IRR 1.13, 95% CI 1.02-1.25, P = 0.02) and non-home discharge destination (OR 1.95, 95% CI 1.35-2.81, P < 0.001) after accounting for patient related factors and surgery type.

CONCLUSIONS

Obesity class 2-3 status has prognostic value in predicting an increased incidence of postoperative complications, increased hospital LOS, and non-home discharge location. These results have important clinical implications for preoperative informed consent and provide areas to target for care improvement for the older obese individual.

Rottlerin inhibits La Crosse virus-induced encephalitis in mice and blocks release of replicating virus from the Golgi body in neurons

La Crosse virus (LACV) is a mosquito-borne orthobunyavirus that causes approximately 60 to 80 hospitalized pediatric encephalitis cases in the United States yearly. The primary treatment for most viral encephalitis, including LACV, is palliative care, and specific antiviral therapeutics are needed. We screened the National Center for Advancing Translational Sciences library of 3,833 FDA-approved and bioactive small molecules for the ability to inhibit LACV-induced death in SH-SY5Y neuronal cells. The top three hits from the initial screen were validated by examining their ability to inhibit virus-induced cell death in multiple neuronal cell lines. Rottlerin consistently reduced LACV-induced death by 50% in multiple human and mouse neuronal cell lines with an effective concentration of 0.16-0.69 µg ml^-1 depending on cell line. Rottlerin was effective up to 12 hours post-infection in vitro and inhibited virus particle trafficking from the Golgi apparatus to trans-Golgi vesicles. In human inducible pluripotent stem cell-derived cerebral organoids, rottlerin reduced virus production by one log and cell death by 35% compared with dimethyl sulfoxide-treated controls. Administration of rottlerin in mice by intraperitoneal or intracranial routes starting at 3 days post-infection decreased disease development by 30-50%. Furthermore, rottlerin also inhibited virus replication of other pathogenic California serogroup orthobunyaviruses (Jamestown Canyon and Tahyna virus) in neuronal cell lines.

The Impact of Surgery duration and Surgery End Time on Postoperative Sleep in Older Adults

Objectives/Background:

Sleep disruption is prevalent in older patients. No previous studies have considered the impact of surgery duration or surgery end time of day on postoperative sleep disruption. Accordingly, we examined the duration of surgery and surgery end times for associations with postoperative sleep disruption.

Methods:

Inclusion criteria were patients ≥ 65 years of age undergoing major, non-cardiac surgery. Sleep disruption was measured by wrist actigraphy and defined as wake after sleep onset (WASO) during the night, or inactivity/sleep time during the day. The sleep opportunity window was set from 22:00 to 06:00 which coincided with “lights off and on” in the hospital. WASO during this 8-hour period on the first postoperative day was categorized into one of three groups: ≤ 15%, 15–25%, and > 25%. Daytime sleep (inactivity) during the first postoperative day was categorized as ≤ 20%, 20–40%, and > 40%. Statistical analyses were conducted to test for associations between surgery duration, surgery end time and sleep disruption on the first postoperative day and following night.

Results:

For this sample of 156 patients, surgery duration ≥ 6 hours and surgery end time after 19:00 were not associated with WASO groups (p = 0.17, p = 0.94, respectively). Furthermore, daytime sleep was also not affected by surgery duration or surgery end time (p = 0.07, p = 0.06 respectively).

Conclusion:

Our hypothesis that patients with longer duration or later-ending operations have increased postoperative sleep disruption was not supported. Our results suggest the pathophysiology of postoperative sleep disruption needs further investigation.

Midazolam Premedication Immediately Before Surgery Is Not Associated With Early Postoperative Delirium

BACKGROUND

Postoperative delirium is common among older surgical patients and may be associated with anesthetic management during the perioperative period. The aim of this study is to assess whether intravenous midazolam, a short-acting benzodiazepine used frequently as premedication, increased the incidence of postoperative delirium.

METHODS

Analyses of existing data were conducted using a database created from 3 prospective studies in patients aged 65 years or older who underwent elective major noncardiac surgery. Postoperative delirium occurring on the first postoperative day was measured using the confusion assessment method. We assessed the association between the use or nonuse of premedication with midazolam and postoperative delirium using a χ2 test, using propensity scores to match up with 3 midazolam patients for each control patient who did not receive midazolam.

RESULTS

A total of 1266 patients were included in this study. Intravenous midazolam was administered as premedication in 909 patients (72%), and 357 patients did not receive midazolam. Those who did and did not receive midazolam significantly differed in age, Charlson comorbidity scores, preoperative cognitive status, preoperative use of benzodiazepines, type of surgery, and year of surgery. Propensity score matching for these variables and American Society of Anesthesiology physical status scores resulted in propensity score-matched samples with 1-3 patients who used midazolam (N = 749) for each patient who did not receive midazolam (N = 357). After propensity score matching, all standardized differences in preoperative patient characteristics ranged from -0.07 to 0.06, indicating good balance on baseline variables between the 2 exposure groups. No association was found between premedication with midazolam and incident delirium on the morning of the first postoperative day in the matched dataset, with odds ratio (95% confidence interval) of 0.91 (0.65-1.29), P = .67.

CONCLUSIONS

Premedication using midazolam was not associated with higher incidence of delirium on the first postoperative day in older patients undergoing major noncardiac surgery.

Strong effects of lab-to-field environmental transitions on the bacterial intestinal microbiota of Mus musculus are modulated by Trichuris murisinfection

Studies of controlled lab animals and natural populations represent two insightful extremes of microbiota research. We bridged these two approaches by transferring lab-bred female C57BL/6 mice from a conventional mouse facility to an acclimation room and then to an outdoor enclosure, to investigate how the gut microbiota changes with environment. Mice residing under constant conditions served as controls. Using 16S rRNA sequencing of fecal samples, we found that the shift in temperature and humidity, as well as exposure to a natural environment, increased microbiota diversity and altered community composition. Community composition in mice exposed to high temperatures and humidity diverged as much from the microbiota of mice housed outdoors as from the microbiota of control mice. Additionally, infection with the nematode Trichuris muris modulated how the microbiota responded to environmental transitions: The dynamics of several families were buffered by the nematodes, while invasion rates of two taxa acquired outdoors were magnified. These findings suggest that gut bacterial communities respond dynamically and simultaneously to changes within the host's body (e.g. the presence of nematodes) and to changes in the wider environment of the host.

Prion-induced photoreceptor degeneration begins with misfolded prion protein accumulation in cones at two distinct sites: cilia and ribbon synapses

Accumulation of misfolded host proteins is central to neuropathogenesis of numerous human brain diseases including prion and prion-like diseases. Neurons of retina are also affected by these diseases. Previously, our group and others found that prion-induced retinal damage to photoreceptor cells in mice and humans resembled pathology of human retinitis pigmentosa caused by mutations in retinal proteins. Here, using confocal, epifluorescent and electron microscopy we followed deposition of disease-associated prion protein (PrPSc) and its association with damage to critical retinal structures following intracerebral prion inoculation. The earliest time and place of retinal PrPSc deposition was 67 days post-inoculation (dpi) on the inner segment (IS) of cone photoreceptors. At 104 and 118 dpi, PrPSc was associated with the base of cilia and swollen cone inner segments, suggesting ciliopathy as a pathogenic mechanism. By 118 dpi, PrPSc was deposited in both rods and cones which showed rootlet damage in the IS, and photoreceptor cell death was indicated by thinning of the outer nuclear layer. In the outer plexiform layer (OPL) in uninfected mice, normal host PrP (PrPC) was mainly associated with cone bipolar cell processes, but in infected mice, at 118 dpi, PrPSc was detected on cone and rod bipolar cell dendrites extending into ribbon synapses. Loss of ribbon synapses in cone pedicles and rod spherules in the OPL was observed to precede destruction of most rods and cones over the next 2–3 weeks. However, bipolar cells and horizontal cells were less damaged, indicating high selectivity among neurons for injury by prions. PrPSc deposition in cone and rod inner segments and on the bipolar cell processes participating in ribbon synapses appear to be critical early events leading to damage and death of photoreceptors after prion infection. These mechanisms may also occur in human retinitis pigmentosa and prion-like diseases, such as AD.

Does postoperative delirium following elective noncardiac surgery predict long-term mortality?

OBJECTIVE

to determine whether incident postoperative delirium in elective older surgical patient was associated with increased risk for mortality, controlling for covariates of 5-year mortality.

DESIGN

secondary analysis of prospective cohort studies.

SETTING

academic Medical Center.

SUBJECTS

patients ≥65 years of age undergoing elective non-cardiac surgery.

OUTCOMES

postoperative assessments of delirium measured using the Confusion Assessment Method (CAM), mortality within 5 years of the index surgery was determined from National Death Index records.

RESULTS

postoperative delirium occurred in 332/1,315 patients (25%). Five years after surgery, 175 patients (13.3%) were deceased. Older age was associated with an increased odds of mortality [odds ratio (OR) 1.90, 95% confidence interval (CI) 1.20-2.70] for those aged 70-79 years compared to those aged <70 years, and OR 3.29, 95% CI 2.14-5.06 for those aged >80 years. Other variables associated with 5-year mortality on bi-variate analyses were white race, self-rated functional status, lower preoperative cognitive status, higher risk score as measured by the American Society of Anesthesiologists (ASA) classification, higher surgical risk score, history of congestive heart failure, myocardial infarction, renal disease, cancer, peripheral vascular disease and postoperative delirium. However, postoperative delirium was not associated with 5-year mortality on multi-variate logistic regression (OR 1.18, 95% CI 0.85-1.65).

CONCLUSIONS

our results showed that delirium was not associated with 5-year mortality in elective surgical patients after consideration of co-variates of mortality. Our results suggest the importance of accounting for known preoperative risks for mortality when investigating the relationship between delirium and long-term mortality.

ADAPT-2: A Randomized Clinical Trial to Reduce Intraoperative EEG Suppression in Older Surgical Patients Undergoing Major Noncardiac Surgery

BACKGROUND

Recent limited evidence suggests that the use of a processed electroencephalographic (EEG) monitor to guide anesthetic management may influence postoperative cognitive outcomes; however, the mechanism is unclear.

METHODS

This exploratory, single-center, randomized clinical trial included patients who were ≥65 years of age undergoing elective noncardiac surgery. The study aimed to determine whether monitoring the brain using a processed EEG monitor reduced EEG suppression and subsequent postoperative delirium. The interventional group received processed EEG-guided anesthetic management to keep the Patient State Index (PSI) above 35 computed by the SEDline Brain Function Monitor (Masimo, Inc, Irvine, CA), while the standard care group was also monitored, but the EEG data were blinded from the clinicians. The primary outcome was intraoperative EEG suppression. A secondary outcome was incident postoperative delirium during the first 3 days after surgery.

RESULTS

All outcomes were analyzed using the intention-to-treat paradigm. Two hundred and four patients with a mean age of 72 ± 5 years were studied. Minutes of EEG suppression adjusted by the length of surgery was found to be less for the interventional group than the standard care group (median [interquartile range], 1.4% [5.0%] and 2.5% [10.4%]; Hodges-Lehmann estimated median difference [95% confidence interval {CI}] of -0.8% [-2.1 to -0.000009]). The effect of the intervention on EEG suppression differed for those with and without preoperative cognitive impairment (interaction P = .01), with the estimated incidence rate ratio (95% CI) of 0.39 (0.33-0.44) for those with preoperative cognitive impairment and 0.48 (0.44-0.51) for those without preoperative cognitive impairment. The incidence of delirium was not found to be different between the interventional (17%) and the standard care groups (20%), risk ratio = 0.85 (95% CI, 0.47-1.5).

CONCLUSIONS

The use of processed EEG to maintain the PSI >35 was associated with less time spent in intraoperative EEG suppression. Preoperative cognitive impairment was associated with a greater percent of surgical time spent in EEG suppression. A larger prospective cohort study to include more cognitively vulnerable patients is necessary to show whether an intervention to reduce EEG suppression is efficacious in reducing postoperative delirium.

Circadian Rhythms in Environmental Health Sciences

PURPOSE OF REVIEW

This review aims to explore how circadian rhythms influence disease susceptibility and potentially modify the effect of environmental exposures. We aimed to identify biomarkers commonly used in environmental health research that have also been the subject of chronobiology studies, in order to review circadian rhythms of relevance to environmental health and determine if time-of-day is an important factor to consider in environmental health studies. Moreover, we discuss opportunities for studying how environmental exposures may interact with circadian rhythms to structure disease pathology and etiology.

RECENT FINDINGS

In recent years, the study of circadian rhythms in mammals has flourished. Animal models revealed that all body tissues have circadian rhythms. In humans, circadian rhythms were also shown to exist at multiple levels of organization: molecular, cellular, and physiological processes, including responding to oxidative stress, cell trafficking, and sex hormone production, respectively. Together, these rhythms are an essential component of human physiology and can shape an individual's susceptibility and response to disease. Circadian rhythms are relatively unexplored in environmental health research. However, circadian clocks control many physiological and behavioral processes that impact exposure pathways and disease systems. We believe this review will motivate new studies of (i) the impact of exposures on circadian rhythms, (ii) how circadian rhythms modify the effect of environmental exposures, and (iii) how time-of-day impacts our ability to observe the body's response to exposure.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Postoperative Delirium Prevention

Postoperative delirium is a geriatric syndrome that manifests as changes in cognition, attention, and levels of consciousness after surgery. It occurs in up to 50% of patients after major surgery and is associated with adverse outcomes, including increased hospital length of stay, higher cost of care, higher rates of institutionalization after discharge, and higher rates of readmission. Furthermore, it is associated with functional decline and cognitive impairments after surgery. As the age and medical complexity of our surgical population increases, practitioners need the skills to identify and prevent delirium in this high-risk population. Because delirium is a common and consequential postoperative complication, there has been an abundance of recent research focused on delirium, conducted by clinicians from a variety of specialties. There have also been several reviews and recommendation statements; however, these have not been based on robust evidence. The Sixth Perioperative Quality Initiative (POQI-6) consensus conference brought together a team of multidisciplinary experts to formally survey and evaluate the literature on postoperative delirium prevention and provide evidence-based recommendations using an iterative Delphi process and Grading of Recommendations Assessment, Development and Evaluation (GRADE) Criteria for evaluating biomedical literature.

Housing laboratory mice deficient for Nod2 and Atg16l1 in a natural environment uncovers genetic and environmental contributions to immune variation

The relative contributions of genetic and environmental factors to variation in immune responses are still poorly understood. Here, we performed a deep phenotypic analysis of immunological parameters of laboratory mice released into an outdoor enclosure, carrying susceptibility genes (Nod2 and Atg16l1) implicated in the development of inflammatory bowel diseases. Variations of immune cell populations were largely driven by environment, whereas cytokine production in response to stimulation was affected more by genetic mutations. Multi-omic models identified transcriptional signatures associated with differences in T cell populations. Subnetworks associated with responses against Clostridium perfringens, Candida albicans and Bacteroides vulgatus were also coupled with rewilding. Hence, exposing laboratory mice carrying different genetic mutations to a natural environment uncovered important contributors to immune variation.

Altered Immunity of Laboratory Mice in the Natural Environment Is Associated with Fungal Colonization

Free-living mammals, such as humans and wild mice, display heightened immune activation compared with artificially maintained laboratory mice. These differences are partially attributed to microbial exposure as laboratory mice infected with pathogens exhibit immune profiles more closely resembling that of free-living animals. Here, we examine how colonization by microorganisms within the natural environment contributes to immune system maturation by releasing inbred laboratory mice into an outdoor enclosure. In addition to enhancing differentiation of T cell populations previously associated with pathogen exposure, outdoor release increased circulating granulocytes. However, these "rewilded" mice were not infected by pathogens previously implicated in immune activation. Rather, immune system changes were associated with altered microbiota composition with notable increases in intestinal fungi. Fungi isolated from rewilded mice were sufficient in increasing circulating granulocytes. These findings establish a model to investigate how the natural environment impacts immune development and show that sustained fungal exposure impacts granulocyte numbers.

Rewilding Nod2 and Atg16l1 Mutant Mice Uncovers Genetic and Environmental Contributions to Microbial Responses and Immune Cell Composition

The relative contributions of genetic and environmental factors to variation in immune responses are poorly understood. Here, we performed a phenotypic analysis of immunological parameters in laboratory mice carrying susceptibility genes implicated in inflammatory bowel disease (IBD) (Nod2 and Atg16l1) upon exposure to environmental microbes. Mice were released into an outdoor enclosure (rewilded) and then profiled for immune responses in the blood and lymph nodes. Variations of immune cell populations were largely driven by the environment, whereas cytokine production elicited by microbial antigens was more affected by the genetic mutations. We identified transcriptional signatures in the lymph nodes associated with differences in T cell populations. Subnetworks associated with responses against Clostridium perfringens, Candida albicans, and Bacteroides vulgatus were also coupled with rewilding. Therefore, exposing laboratory mice with genetic mutations to a natural environment uncovers different contributions to variations in microbial responses and immune cell composition.

A doublecortin-domain protein of Toxoplasma and its orthologues bind to and modify the structure and organization of tubulin polymers

BACKGROUND

TgDCX is a doublecortin-domain protein associated with the conoid fibers, a set of strongly curved non-tubular tubulin-polymers in Toxoplasma. TgDCX deletion impairs conoid structure and parasite invasion. TgDCX contains two tubulin-binding domains: a partial P25α and the DCX/doublecortin domain. Orthologues are found in apicomplexans and their free-living relatives Chromera and Vitrella.

RESULTS

We report that isolated TgDCX-containing conoid fibers retain their pronounced curvature, but loss of TgDCX destabilizes the fibers. We crystallized and determined the 3D-structure of the DCX-domain, which is similar to those of human doublecortin and well-conserved among TgDCX orthologues. However, the orthologues vary widely in targeting to the conoid in Toxoplasma and in modulating microtubule organization in Xenopus cells. Several orthologues bind to microtubules in Xenopus cells, but only TgDCX generates short, strongly curved microtubule arcs. EM analysis shows microtubules decorated with TgDCX bundled into rafts, often bordered on one edge by a "C"-shaped incomplete tube. A Chromera orthologue closely mimics TgDCX targeting in Toxoplasma and binds to microtubules in Xenopus cells, but does not generate arcs or "C"-shaped tubes, and fails to rescue the defects of the TgDCX-knockout parasite.

CONCLUSIONS

These observations suggest that species-specific features of TgDCX enable it to generate strongly curved tubulin-polymers to support efficient host-cell invasion.

Adherence to recommended practices for perioperative anesthesia care for older adults among US anesthesiologists: results from the ASA Committee on Geriatric Anesthesia-Perioperative Brain Health Initiative ASA member survey

BACKGROUND

While specific practices for perioperative care of older adults have been recommended, little is known regarding adherence by US physician anesthesiologists to such practices. To address this gap in knowledge, the ASA Committee on Geriatric Anesthesia and the ASA Perioperative Brain Health Initiative undertook a survey of ASA members to characterize current practices related to perioperative care of older adults.

METHODS

We administered a web-based questionnaire with items assessing the proportion of practice focused on delivery of care to older adults, adherence to recommended practices for older surgical patients, resource needs to improve care, and practice characteristics.

RESULTS

Responses were collected between May 24, 2018, and June 29, 2018. A total of 25,587 ASA members were invited to participate, and 1737 answered at least one item (6.8%). 96.4% of respondents reported that they had cared for a patient aged 65 or older within the last year. 47.1% of respondents (95% confidence interval, 44.6%, 49.7%) reported using multimodal analgesia among patients aged 65 and older at least 90% of the time, and 25.5% (95% CI, 23.3%, 27.7%) provided preoperative information regarding postoperative cognitive changes at least 90% of the time. Over 80% of respondents reported that preoperative screening for frailty or dementia, postoperative screening for delirium, and preoperative geriatric consultation occurred in fewer than 10% of cases. Development of practice guidelines for geriatric anesthesia care and expansion of web-based resources were most frequently prioritized by respondents as initiatives to improve care in this domain.

DISCUSSION

Most survey respondents reported providing anesthesia care to older adults, but adherence to recommended practices varied across the six items assessed. Reported rates of screening for common geriatric syndromes, such as frailty, delirium, and dementia, were low among survey respondents. Respondents identified multiple opportunities for ASA initiatives to support efforts to improve care for older surgical patients.

Centrin2 from the human parasite Toxoplasma gondii is required for its invasion and intracellular replication

Centrins are EF-hand containing proteins ubiquitously found in eukaryotes and are key components of centrioles/basal bodies as well as certain contractile fibers. We previously identified three centrins in the human parasite Toxoplasma gondii, all of which localized to the centrioles. However, one of them, T. gondii (Tg) Centrin2 (CEN2), is also targeted to structures at the apical and basal ends of the parasite, as well as to annuli at the base of the apical cap of the membrane cortex. The role(s) that CEN2 play in these locations were unknown. Here, we report the functional characterization of CEN2 using a conditional knockdown method that combines transcriptional and protein stability control. The knockdown resulted in an ordered loss of CEN2 from its four compartments, due to differences in incorporation kinetics and structural inheritance over successive generations. This was correlated with a major invasion deficiency at early stages of CEN2 knockdown, and replication defects at later stages. These results indicate that CEN2 is incorporated into multiple cytoskeletal structures to serve distinct functions that are required for parasite survival.

Integration of multi-omics data from re-wilded laboratory mice to identify key parameters that determine immune heterogeneity and activation

Current research on immunology are largely based on clean laboratory mice kept in specific pathogen free (SPF) environments. They have the advantage of being inbred, genetically homogeneous and can be manipulated genetically in disease models. However, humans as with all free-living mammals face a more complex environment and are exposed to various food resources, microbial experiences, thermogenic changes, and must constantly respond to environmental challenges. We have established a unique experimental system in which laboratory mice are “re-wilded” through release into an outdoor enclosure facility. Here, we use multi-parameter assays including 16S/Metagenomic sequencing, intestinal RNA-sequencing, and 34 parameters of flow cytometry to explain heterogeneity of immune responses from exposure to the wild environment. Increased immune activation of re-wilded mice occur in the absence of viral, bacterial or parasitic pathogen exposure in this enclosure, including increase of CD4+ and CD8+ memory T cells, effector T cells, innate lymphoid cells (ILCs), circulating neutrophils, reduction in naïve T cells, and increased expression of costimulatory molecules on antigen presenting cells. When we examined cytokine production in response to ex vivo stimulation of mesenteric lymph node cells with 8 bacterial and fungal stimuli, the mesenteric lymph node cells from re-wilded mice are poised for different responses via robust induction of cytokines than laboratory mice. By using machine learning models, we are integrating these multi-omic datasets to better predict the association between environmental and host genetic factors on driving heterogeneity of immune responses in the re-wilded mice.

Hedgehog signaling in the airway epithelium of patients with chronic obstructive pulmonary disease

Genome-wide association studies have linked gene variants of the receptor patched homolog 1 (PTCH1) with chronic obstructive pulmonary disease (COPD). However, its biological role in the disease is unclear. Our objective was to determine the expression pattern and biological role of PTCH1 in the lungs of patients with COPD. Airway epithelial-specific PTCH1 protein expression and epithelial morphology were assessed in lung tissues of control and COPD patients. PTCH1 mRNA expression was measured in bronchial epithelial cells obtained from individuals with and without COPD. The effects of PTCH1 siRNA knockdown on epithelial repair and mucous expression were evaluated using human epithelial cell lines. Ptch1^+/− mice were used to assess the effect of decreased PTCH1 on mucous expression and airway epithelial phenotypes. Airway epithelial-specific PTCH1 protein expression was significantly increased in subjects with COPD compared to controls, and its expression was associated with total airway epithelial cell count and thickness. PTCH1 knockdown attenuated wound closure and mucous expression in airway epithelial cell lines. Ptch1^+/− mice had reduced mucous expression compared to wildtype mice following mucous induction. PTCH1 protein is up-regulated in COPD airway epithelium and may upregulate mucous expression. PTCH1 provides a novel target to reduce chronic bronchitis in COPD patients.

Volatile anaesthetics and postoperative delirium in older surgical patients-A secondary analysis of prospective cohort studies

BACKGROUND

Volatile Anaesthetics (VAs) may be associated with postoperative delirium (POD). However, to date, the effects of VAs on POD are not completely understood. The objective of this study was to investigate the incidence of POD in different VA groups.

METHODS

A secondary analysis was conducted using a database created from prospective cohort studies in patients who underwent elective major noncardiac surgery. Patients who received general anaesthesia with desflurane, isoflurane, or sevoflurane were included in the study. POD occurring on either of the first two postoperative days was measured using the Confusion Assessment Method.

RESULTS

Five hundred and thirty-two patients were included in this study, with a mean age of 73.5 ± 6.0 years (range, 65-96 years). The overall incidence of POD on either postoperative day 1 or 2 was 41%. A higher incidence of POD was noted in the desflurane group compared with the isoflurane group (Odds Ratio = 3.35, 95% CI = 1.54-7.28). The incidence of POD between the sevoflurane and isoflurane or desflurane group was not statistically significant.

CONCLUSION

Each VA may have different effects on postoperative cognition. Further studies using a prospective randomized approach will be necessary to discern whether anaesthetic type or management affects the occurrence of postoperative delirium.

Burst-suppression ratio underestimates absolute duration of electroencephalogram suppression compared with visual analysis of intraoperative electroencephalogram

Background

Machine-generated indices based on quantitative electroencephalography (EEG), such as the patient state index (PSI™) and burst-suppression ratio (BSR), are increasingly being used to monitor intraoperative depth of anaesthesia in the endeavour to improve postoperative neurological outcomes, such as postoperative delirium (POD). However, the accuracy of the BSR compared with direct visualization of the EEG trace with regard to the prediction of POD has not been evaluated previously.

Methods

Forty-one consecutive patients undergoing non-cardiac, non-intracranial surgery with general anaesthesia wore a SedLine ® monitor during surgery and were assessed after surgery for the presence of delirium with the Confusion Assessment Method. The intraoperative EEG was scanned for absolute minutes of EEG suppression and correlated with the incidence of POD. The BSR and PSI™ were compared between patients with and without POD.

Results

Visual analysis of the EEG by neurologists and the SedLine ® -generated BSR provided a significantly different distribution of estimated minutes of EEG suppression ( P =0.037). The Sedline ® system markedly underestimated the amount of EEG suppression. The number of minutes of suppression assessed by visual analysis of the EEG was significantly associated with POD ( P =0.039), whereas the minutes based on the BSR generated by SedLine ® were not associated with POD ( P =0.275).

Conclusions

Our findings suggest that SedLine ® (machine)-generated indices might underestimate the minutes of EEG suppression, thereby reducing the sensitivity for detecting patients at risk for POD. Thus, the monitoring of machine-generated BSR and PSI™ might benefit from the addition of a visual tracing of the EEG to achieve a more accurate and real-time guidance of anaesthesia depth monitoring and the ultimate goal, to reduce the risk of POD.

The effects of living in an outdoor enclosure on hippocampal plasticity and anxiety-like behavior in response to nematode infection

The hippocampus of rodents undergoes structural remodeling throughout adulthood, including the addition of new neurons. Adult neurogenesis is sensitive to environmental enrichment and stress. Microglia, the brain's resident immune cells, are involved in adult neurogenesis by engulfing dying new neurons. While previous studies using laboratory environmental enrichment have investigated alterations in brain structure and function, they do not provide an adequate reflection of living in the wild, in which stress and environmental instability are common. Here, we compared mice living in standard laboratory settings to mice living in outdoor enclosures to assess the complex interactions among environment, gut infection, and hippocampal plasticity. We infected mice with parasitic worms and studied their effects on adult neurogenesis, microglia, and functions associated with the hippocampus, including cognition and anxiety regulation. We found an increase in immature neuron numbers of mice living in outdoor enclosures regardless of infection. While outdoor living prevented increases in microglial reactivity induced by infection in both the dorsal and ventral hippocampus, outdoor mice with infection had fewer microglia and microglial processes in the ventral hippocampus. We observed no differences in cognitive performance on the hippocampus-dependent object location task between infected and uninfected mice living in either setting. However, we found that infection caused an increase in anxiety-like behavior in the open field test but only in outdoor mice. These findings suggest that living conditions, as well as gut infection, interact to produce complex effects on brain structure and function.

Parasite-Microbiota Interactions With the Vertebrate Gut: Synthesis Through an Ecological Lens

The vertebrate gut teems with a large, diverse, and dynamic bacterial community that has pervasive effects on gut physiology, metabolism, and immunity. Under natural conditions, these microbes share their habitat with a similarly dynamic community of eukaryotes (helminths, protozoa, and fungi), many of which are well-known parasites. Both parasites and the prokaryotic microbiota can dramatically alter the physical and immune landscape of the gut, creating ample opportunities for them to interact. Such interactions may critically alter infection outcomes and affect overall host health and disease. For instance, parasite infection can change how a host interacts with its bacterial flora, either driving or protecting against dysbiosis and inflammatory disease. Conversely, the microbiota can alter a parasite's colonization success, replication, and virulence, shifting it along the parasitism-mutualism spectrum. The mechanisms and consequences of these interactions are just starting to be elucidated in an emergent transdisciplinary area at the boundary of microbiology and parasitology. However, heterogeneity in experimental designs, host and parasite species, and a largely phenomenological and taxonomic approach to synthesizing the literature have meant that common themes across studies remain elusive. Here, we use an ecological perspective to review the literature on interactions between the prokaryotic microbiota and eukaryotic parasites in the vertebrate gut. Using knowledge about parasite biology and ecology, we discuss mechanisms by which they may interact with gut microbes, the consequences of such interactions for host health, and how understanding parasite-microbiota interactions may lead to novel approaches in disease control.

Rapid environmental effects on gut nematode susceptibility in rewilded mice

Genetic and environmental factors shape host susceptibility to infection, but how and how rapidly environmental variation might alter the susceptibility of mammalian genotypes remains unknown. Here, we investigate the impacts of seminatural environments upon the nematode susceptibility profiles of inbred C57BL/6 mice. We hypothesized that natural exposure to microbes might directly (e.g., via trophic interactions) or indirectly (e.g., via microbe-induced immune responses) alter the hatching, growth, and survival of nematodes in mice housed outdoors. We found that while C57BL/6 mice are resistant to high doses of nematode (Trichuris muris) eggs under clean laboratory conditions, exposure to outdoor environments significantly increased their susceptibility to infection, as evidenced by increased worm burdens and worm biomass. Indeed, mice kept outdoors harbored as many worms as signal transducer and activator of transcription 6 (STAT6) knockout mice, which are genetically deficient in the type 2 immune response essential for clearing nematodes. Using 16S ribosomal RNA sequencing of fecal samples, we discovered enhanced microbial diversity and specific bacterial taxa predictive of nematode burden in outdoor mice. We also observed decreased type 2 and increased type 1 immune responses in lamina propria and mesenteric lymph node (MLN) cells from infected mice residing outdoors. Importantly, in our experimental design, different groups of mice received nematode eggs either before or after moving outdoors. This contrasting timing of rewilding revealed that enhanced hatching of worms was not sufficient to explain the increased worm burdens; instead, microbial enhancement and type 1 immune facilitation of worm growth and survival, as hypothesized, were also necessary to explain our results. These findings demonstrate that environment can rapidly and significantly shape gut microbial communities and mucosal responses to nematode infections, leading to variation in parasite expulsion rates among genetically similar hosts.

The environment in which an individual resides is likely to change how she or he responds to infection. However, most of our understanding about host responses to infection arises from experimental studies conducted under uniform environmental conditions in the laboratory. We wished to investigate whether findings in the laboratory translate into the wild. Therefore, in this study, we placed common strains of laboratory mice into large, outdoor enclosures to investigate how a more natural environment might impact their ability to combat intestinal worm infections. We found that while mice are able to clear worm infections in the laboratory, mice residing outdoors harbored higher worm burdens and larger worms than their laboratory cousins. The longer the mice lived outdoors, the greater the number and size of worms in their guts. We found that outdoor mice harbored more diverse gut microbes and even specific bacteria that may have impacted worm growth and survival inside the mice. Mice kept outdoors also produced decreased immune responses of the type essential for worm expulsion. Together, these results demonstrate that the external environment significantly alters how a host responds to worms and germs in her or his gut, thereby leading to variation in the outcome of infections.

Integrated Analysis of Biopsies from Inflammatory Bowel Disease Patients Identifies SAA1 as a Link Between Mucosal Microbes with TH17 and TH22 Cells

BACKGROUND

Inflammatory bowel diseases (IBD) are believed to be driven by dysregulated interactions between the host and the gut microbiota. Our goal is to characterize and infer relationships between mucosal T cells, the host tissue environment, and microbial communities in patients with IBD who will serve as basis for mechanistic studies on human IBD.

METHODS

We characterized mucosal CD4 T cells using flow cytometry, along with matching mucosal global gene expression and microbial communities data from 35 pinch biopsy samples from patients with IBD. We analyzed these data sets using an integrated framework to identify predictors of inflammatory states and then reproduced some of the putative relationships formed among these predictors by analyzing data from the pediatric RISK cohort.

RESULTS

We identified 26 predictors from our combined data set that were effective in distinguishing between regions of the intestine undergoing active inflammation and regions that were normal. Network analysis on these 26 predictors revealed SAA1 as the most connected node linking the abundance of the genus Bacteroides with the production of IL17 and IL22 by CD4 T cells. These SAA1-linked microbial and transcriptome interactions were further reproduced with data from the pediatric IBD RISK cohort.

CONCLUSIONS

This study identifies expression of SAA1 as an important link between mucosal T cells, microbial communities, and their tissue environment in patients with IBD. A combination of T cell effector function data, gene expression and microbial profiling can distinguish between intestinal inflammatory states in IBD regardless of disease types.

Parasites lacking the micronemal protein MIC2 are deficient in surface attachment and host cell egress, but remain virulent in vivo

Background: Micronemal proteins of the thrombospondin-related anonymous protein (TRAP) family are believed to play essential roles during gliding motility and host cell invasion by apicomplexan parasites, and currently represent major vaccine candidates against Plasmodium falciparum, the causative agent of malaria. However, recent evidence suggests that they play multiple and different roles than previously assumed. Here, we analyse a null mutant for MIC2, the TRAP homolog in Toxoplasma gondii. Methods: We performed a careful analysis of parasite motility in a 3D-environment, attachment under shear stress conditions, host cell invasion and in vivo virulence. Results: We verified the role of MIC2 in efficient surface attachment, but were unable to identify any direct function of MIC2 in sustaining gliding motility or host cell invasion once initiated. Furthermore, we find that deletion of mic2 causes a slightly delayed infection in vivo, leading only to mild attenuation of virulence; like with wildtype parasites, inoculation with even low numbers of mic2 KO parasites causes lethal disease in mice. However, deletion of mic2 causes delayed host cell egress in vitro, possibly via disrupted signal transduction pathways. Conclusions: We confirm a critical role of MIC2 in parasite attachment to the surface, leading to reduced parasite motility and host cell invasion. However, MIC2 appears to not be critical for gliding motility or host cell invasion, since parasite speed during these processes is unaffected. Furthermore, deletion of MIC2 leads only to slight attenuation of the parasite.

Parasites lacking the micronemal protein MIC2 are deficient in surface attachment and host cell egress, but remain virulent in vivo

Background: Micronemal proteins of the thrombospondin-related anonymous protein (TRAP) family are believed to play essential roles during gliding motility and host cell invasion by apicomplexan parasites, and currently represent major vaccine candidates against Plasmodium falciparum, the causative agent of malaria. However, recent evidence suggests that they play multiple and different roles than previously assumed. Here, we analyse a null mutant for MIC2, the TRAP homolog in Toxoplasma gondii. Methods: We performed a careful analysis of parasite motility in a 3D-environment, attachment under shear stress conditions, host cell invasion and in vivo virulence. Results: We verified the role of MIC2 in efficient surface attachment, but were unable to identify any direct function of MIC2 in sustaining gliding motility or host cell invasion once initiated. Furthermore, we find that deletion of mic2 causes a slightly delayed infection in vivo, leading only to mild attenuation of virulence; like with wildtype parasites, inoculation with even low numbers of mic2 KO parasites causes lethal disease in mice. However, deletion of mic2 causes delayed host cell egress in vitro, possibly via disrupted signal transduction pathways. Conclusions: We confirm a critical role of MIC2 in parasite attachment to the surface, leading to reduced parasite motility and host cell invasion. However, MIC2 appears to not be critical for gliding motility or host cell invasion, since parasite speed during these processes is unaffected. Furthermore, deletion of MIC2 leads only to slight attenuation of the parasite.

The Feasibility and Utility of Continuous Sleep Monitoring in Critically Ill Patients Using a Portable Electroencephalography Monitor

BACKGROUND

Sleep disruption in critically ill adults can result in acute decrements in cognitive function, including delirium, but it is underdiagnosed in the setting of the intensive care unit (ICU). Although sleep stages can be assessed by polysomnography (PSG), acquisition and interpretation of PSG is costly, is labor intensive, is difficult to do over an extended period of time with critically ill patients (multiple days of continuous recording), and may interfere with patient care. In this pilot study, we investigated the feasibility and utility of monitoring sleep in the ICU setting using a portable electroencephalography (EEG) monitor, the SedLine brain monitor.

METHODS

We first performed a baseline comparison study of the SedLine brain monitor by comparing its recordings to PSG recorded in a sleep laboratory (n = 3). In a separate patient cohort, we enrolled patients in the ICU who were monitored continuously with the SedLine monitor for sleep disruption (n = 23). In all enrolled patients, we continuously monitored their EEG. The raw EEG was retrieved and sleep stages and arousals were analyzed by a board-certified technologist. Delirium was measured by a trained research nurse using the Confusion Assessment Method developed for the ICU.

RESULTS

For all enrolled patients, we continuously monitored their EEGs and were able to retrieve the raw EEGs for analysis of sleep stages. Overall, the SedLine brain monitor was able to differentiate sleep stages, as well as capture arousals and transitions between sleep stages compared with the PSG performed in the sleep laboratory. The percentage agreement was 67% for the wake stage, 77% for the non-rapid eye movement (REM) stage (N1 = 29%, N2 = 88%, and N3 = 6%), and 89% for the REM stage. The overall agreement was measured with the use of weighted kappa, which was 0.61, 95% confidence interval, 0.58 to 0.64. In the ICU study, the mean recording time for the 23 enrolled patients was 19.10 hours. There were several signs indicative of poor-quality sleep, where sleep was distributed throughout the day, with reduced time spent in REM (1.38% ± 2.74% of total sleep time), and stage N3 (2.17% ± 5.53% of total sleep time) coupled with a high arousal index (34.63 ± 19.04 arousals per hour). The occurrence of ICU delirium was not significantly different between patients with and without sleep disruption.

CONCLUSIONS

Our results suggest the utility of a portable EEG monitor to measure different sleep stages, transitions, and arousals; however, the accuracy in measuring different sleep stages by the SedLine monitor varies compared with PSG. Our results also support previous findings that sleep is fragmented in critically ill patients. Further research is necessary to develop portable EEG monitors that have higher agreement with PSG.

Stability and function of a putative microtubule-organizing center in the human parasite Toxoplasma gondii

KinesinA and APR1 maintain the stability of the apical polar ring, a putative organizing center for the 22 cortical microtubules of Toxoplasma. Parasites lacking these two proteins are defective in invasion, motility, secretion, and growth but can still make 22 cortical microtubules, suggesting that ring stability is not tightly coupled to templating.

The organization of the microtubule cytoskeleton is dictated by microtubule nucleators or organizing centers. Toxoplasma gondii, an important human parasite, has an array of 22 regularly spaced cortical microtubules stemming from a hypothesized organizing center, the apical polar ring. Here we examine the functions of the apical polar ring by characterizing two of its components, KinesinA and APR1, and show that its putative role in templating can be separated from its mechanical stability. Parasites that lack both KinesinA and APR1 (ΔkinesinAΔapr1) are capable of generating 22 cortical microtubules. However, the apical polar ring is fragmented in live ΔkinesinAΔapr1 parasites and is undetectable by electron microscopy after detergent extraction. Disintegration of the apical polar ring results in the detachment of groups of microtubules from the apical end of the parasite. These structural defects are linked to a diminished ability of the parasite to move and invade host cells, as well as decreased secretion of effectors important for these processes. Together the findings demonstrate the importance of the structural integrity of the apical polar ring and the microtubule array in the Toxoplasma lytic cycle, which is responsible for massive tissue destruction in acute toxoplasmosis.

Surface attachment, promoted by the actomyosin system of Toxoplasma gondii is important for efficient gliding motility and invasion

Background

Apicomplexan parasites employ a unique form of movement, termed gliding motility, in order to invade the host cell. This movement depends on the parasite’s actomyosin system, which is thought to generate the force during gliding. However, recent evidence questions the exact molecular role of this system, since mutants for core components of the gliding machinery, such as parasite actin or subunits of the MyoA-motor complex (the glideosome), remain motile and invasive, albeit at significantly reduced efficiencies. While compensatory mechanisms and unusual polymerisation kinetics of parasite actin have been evoked to explain these findings, the actomyosin system could also play a role distinct from force production during parasite movement.

Results

In this study, we compared the phenotypes of different mutants for core components of the actomyosin system in Toxoplasma gondii to decipher their exact role during gliding motility and invasion. We found that, while some phenotypes (apicoplast segregation, host cell egress, dense granule motility) appeared early after induction of the act1 knockout and went to completion, a small percentage of the parasites remained capable of motility and invasion well past the point at which actin levels were undetectable. Those act1 conditional knockout (cKO) and mlc1 cKO that continue to move in 3D do so at speeds similar to wildtype parasites. However, these mutants are virtually unable to attach to a collagen-coated substrate under flow conditions, indicating an important role for the actomyosin system of T. gondii in the formation of attachment sites.

Conclusion

We demonstrate that parasite actin is essential during the lytic cycle and cannot be compensated by other molecules. Our data suggest a conventional polymerisation mechanism in vivo that depends on a critical concentration of G-actin. Importantly, we demonstrate that the actomyosin system of the parasite functions in attachment to the surface substrate, and not necessarily as force generator.

Electronic supplementary material

The online version of this article (doi:10.1186/s12915-016-0343-5) contains supplementary material, which is available to authorized users.

Perioperative cerebrospinal fluid and plasma inflammatory markers after orthopedic surgery

Background

Postoperative delirium is prevalent in older patients and associated with worse outcomes. Recent data in animal studies demonstrate increases in inflammatory markers in plasma and cerebrospinal fluid (CSF) even after aseptic surgery, suggesting that inflammation of the central nervous system may be part of the pathogenesis of postoperative cognitive changes. We investigated the hypothesis that neuroinflammation was an important cause for postoperative delirium and cognitive dysfunction after major non-cardiac surgery.

Methods

After Institutional Review Board approval and informed consent, we recruited patients undergoing major knee surgery who received spinal anesthesia and femoral nerve block with intravenous sedation. All patients had an indwelling spinal catheter placed at the time of spinal anesthesia that was left in place for up to 24 h. Plasma and CSF samples were collected preoperatively and at 3, 6, and 18 h postoperatively. Cytokine levels were measured using ELISA and Luminex. Postoperative delirium was determined using the confusion assessment method, and cognitive dysfunction was measured using validated cognitive tests (word list, verbal fluency test, digit symbol test).

Results

Ten patients with complete datasets were included. One patient developed postoperative delirium, and six patients developed postoperative cognitive dysfunction. Postoperatively, at different time points, statistically significant changes compared to baseline were present in IL-5, IL-6, I-8, IL-10, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, IL-6/IL-10, and receptor for advanced glycation end products in plasma and in IFN-γ, IL-6, IL-8, IL-10, MCP-1, MIP-1α, MIP-1β, IL-8/IL-10, and TNF-α in CSF.

Conclusions

Substantial pro- and anti-inflammatory activity in the central neural system after surgery was found. If confirmed by larger studies, persistent changes in cytokine levels may serve as biomarkers for novel clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0681-9) contains supplementary material, which is available to authorized users.

Simultaneous multiview capture and fusion improves spatial resolution in wide-field and light-sheet microscopy

Most fluorescence microscopes are inefficient, collecting only a small fraction of the emitted light at any instant. Besides wasting valuable signal, this inefficiency also reduces spatial resolution and causes imaging volumes to exhibit significant resolution anisotropy. We describe microscopic and computational techniques that address these problems by simultaneously capturing and subsequently fusing and deconvolving multiple specimen views. Unlike previous methods that serially capture multiple views, our approach improves spatial resolution without introducing any additional illumination dose or compromising temporal resolution relative to conventional imaging. When applying our methods to single-view wide-field or dual-view light-sheet microscopy, we achieve a twofold improvement in volumetric resolution (~235 nm × 235 nm × 340 nm) as demonstrated on a variety of samples including microtubules in Toxoplasma gondii, SpoVM in sporulating Bacillus subtilis, and multiple protein distributions and organelles in eukaryotic cells. In every case, spatial resolution is improved with no drawback by harnessing previously unused fluorescence.

The impact of albendazole treatment on the incidence of viral- and bacterial-induced diarrhea in school children in southern Vietnam: study protocol for a randomized controlled trial

Background

Anthelmintics are one of the more commonly available classes of drugs to treat infections by parasitic helminths (especially nematodes) in the human intestinal tract. As a result of their cost-effectiveness, mass school-based deworming programs are becoming routine practice in developing countries. However, experimental and clinical evidence suggests that anthelmintic treatments may increase susceptibility to other gastrointestinal infections caused by bacteria, viruses, or protozoa. Hypothesizing that anthelmintics may increase diarrheal infections in treated children, we aim to evaluate the impact of anthelmintics on the incidence of diarrheal disease caused by viral and bacterial pathogens in school children in southern Vietnam.

Methods/design

This is a randomized, double-blinded, placebo-controlled trial to investigate the effects of albendazole treatment versus placebo on the incidence of viral- and bacterial-induced diarrhea in 350 helminth-infected and 350 helminth-uninfected Vietnamese school children aged 6–15 years. Four hundred milligrams of albendazole, or placebo treatment will be administered once every 3 months for 12 months. At the end of 12 months, all participants will receive albendazole treatment. The primary endpoint of this study is the incidence of diarrheal disease assessed by 12 months of weekly active and passive case surveillance. Secondary endpoints include the prevalence and intensities of helminth, viral, and bacterial infections, alterations in host immunity and the gut microbiota with helminth and pathogen clearance, changes in mean z scores of body weight indices over time, and the number and severity of adverse events.

Discussion

In order to reduce helminth burdens, anthelmintics are being routinely administered to children in developing countries. However, the effects of anthelmintic treatment on susceptibility to other diseases, including diarrheal pathogens, remain unknown. It is important to monitor for unintended consequences of drug treatments in co-infected populations. In this trial, we will examine how anthelmintic treatment impacts host susceptibility to diarrheal infections, with the aim of informing deworming programs of any indirect effects of mass anthelmintic administrations on co-infecting enteric pathogens.

Trial registration

ClinicalTrials.gov: NCT02597556. Registered on 3 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1406-1) contains supplementary material, which is available to authorized users.

Preoperative Sleep Disruption and Postoperative Delirium

STUDY OBJECTIVES

To describe preoperative and postoperative sleep disruption and its relationship to postoperative delirium.

DESIGN

Prospective cohort study with 6 time points (3 nights pre-hospitalization and 3 nights post-surgery).

SETTING

University medical center.

PATIENTS

The sample consisted of 50 English-speaking patients ≥ 40 years of age scheduled for major non-cardiac surgery, with an anticipated hospital stay ≥ 3 days.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Sleep was measured before and after surgery for a total of 6 days using a wrist actigraph to quantify movement in a continuous fashion. Postoperative delirium was measured by a structured interview using the Confusion Assessment Method. Sleep variables for patients with (n = 7) and without (n = 43) postoperative delirium were compared using the unpaired Student t-tests or χ(2) tests. Repeated measures analysis of variance for the 6 days was used to examine within-subject changes over time and between group differences. The mean age of the patients was 66 ± 11 years (range 43-91 years), and it was not associated with sleep variables or postoperative delirium. The incidence of postoperative delirium observed during any of the 3 postoperative days was 14%. For the 7 patients who subsequently developed postoperative delirium, wake after sleep onset (WASO) as a percentage of total sleep time was significantly higher (44% ± 22%) during the night before surgery compared to the patients who did not subsequently developed delirium (21% ± 20%, p = 0.012). This sleep disruption continued postoperatively, and to a greater extent, for the first 2 nights after surgery. Patients with WASO < 10% did not experience postoperative delirium. Self-reported sleep disturbance did not differ between patients with vs. without postoperative delirium.

CONCLUSIONS

In this pilot study of adults over 40 years of age, sleep disruption was more severe before surgery in the patients who experienced postoperative delirium. A future larger study is necessary to confirm our results and determine if poor sleep is associated with delirium in larger samples and what specific sleep problems best predict postoperative delirium in older surgical patients.