The effect of prolonged spaceflight on cerebrospinal fluid and perivascular spaces of astronauts and cosmonauts.

Long-duration spaceflight induces changes to the brain and cerebrospinal fluid compartments and visual acuity problems known as spaceflight-associated neuro-ocular syndrome (SANS). The clinical relevance of these changes and whether they equally affect crews of different space agencies remain unknown. We used MRI to analyze the alterations occurring in the perivascular spaces (PVS) in NASA and European Space Agency astronauts and Roscosmos cosmonauts after a 6-mo spaceflight on the International Space Station (ISS). We found increased volume of basal ganglia PVS and white matter PVS (WM-PVS) after spaceflight, which was more prominent in the NASA crew than the Roscosmos crew. Moreover, both crews demonstrated a similar degree of lateral ventricle enlargement and decreased subarachnoid space at the vertex, which was correlated with WM-PVS enlargement. As all crews experienced the same environment aboard the ISS, the differences in WM-PVS enlargement may have been due to, among other factors, differences in the use of countermeasures and high-resistive exercise regimes, which can influence brain fluid redistribution. Moreover, NASA astronauts who developed SANS had greater pre- and postflight WM-PVS volumes than those unaffected. These results provide evidence for a potential link between WM-PVS fluid and SANS.

Endothelial neuropilin-2 influences angiogenesis by regulating actin pattern development and α5-integrin-p-FAK complex recruitment to assembling adhesion sites.

The ability to form a variety of cell-matrix connections is crucial for angiogenesis to take place. Without stable anchorage to the extracellular matrix (ECM), endothelial cells (ECs) are unable to sense, integrate and disseminate growth factor stimulated responses that drive growth of a vascular bed. Neuropilin-2 (NRP2) is a widely expressed membrane-bound multifunctional non-tyrosine kinase receptor, which has previously been implicated in influencing cell adhesion and migration by interacting with α5-integrin and regulating adhesion turnover. α5-integrin, and its ECM ligand fibronectin (FN) are both known to be upregulated during the formation of neo-vasculature. Despite being descriptively annotated as a candidate biomarker for aggressive cancer phenotypes, the EC-specific roles for NRP2 during developmental and pathological angiogenesis remain unexplored. The data reported here support a model whereby NRP2 actively promotes EC adhesion and migration by regulating dynamic cytoskeletal remodeling and by stimulating Rab11-dependent recycling of α5-integrin-p-FAK complexes to newly assembling adhesion sites. Furthermore, temporal depletion of EC-NRP2 in vivo impairs primary tumor growth by disrupting vessel formation. We also demonstrate that EC-NRP2 is required for normal postnatal retinal vascular development, specifically by regulating cell-matrix adhesion. Upon loss of endothelial NRP2, vascular outgrowth from the optic nerve during superficial plexus formation is disrupted, likely due to reduced FAK phosphorylation within sprouting tip cells.

Fiber ball white matter modeling in focal epilepsy.

Multicompartment diffusion magnetic resonance imaging (MRI) approaches are increasingly being applied to estimate intra-axonal and extra-axonal diffusion characteristics in the human brain. Fiber ball imaging (FBI) and its extension fiber ball white matter modeling (FBWM) are such recently described multicompartment approaches. However, these particular approaches have yet to be applied in clinical cohorts. The modeling of several diffusion parameters with interpretable biological meaning may offer the development of new, noninvasive biomarkers of pharmacoresistance in epilepsy. In the present study, we used FBI and FBWM to evaluate intra-axonal and extra-axonal diffusion properties of white matter tracts in patients with longstanding focal epilepsy. FBI/FBWM diffusion parameters were calculated along the length of 50 white matter tract bundles and statistically compared between patients with refractory epilepsy, nonrefractory epilepsy and controls. We report that patients with chronic epilepsy had a widespread distribution of extra-axonal diffusivity relative to controls, particularly in circumscribed regions along white matter tracts projecting to cerebral cortex from thalamic, striatal, brainstem, and peduncular regions. Patients with refractory epilepsy had significantly greater markers of extra-axonal diffusivity compared to those with nonrefractory epilepsy. The extra-axonal diffusivity alterations in patients with epilepsy observed in the present study could be markers of neuroinflammatory processes or a reflection of reduced axonal density, both of which have been histologically demonstrated in focal epilepsy. FBI is a clinically feasible MRI approach that provides the basis for more interpretive conclusions about the microstructural environment of the brain and may represent a unique biomarker of pharmacoresistance in epilepsy.

Altered cerebral perfusion in response to chronic mild hypercapnia and head-down tilt Bed rest as an analog for Spaceflight.

PURPOSE: Following prolonged stays on the International Space Station (ISS), some astronauts exhibit visual acuity changes, ophthalmological findings, and mildly elevated intracranial pressures as part of a novel process called spaceflight-associated neuro-ocular syndrome (SANS). To determine the pathophysiology of SANS, NASA conducted a multi-investigator study in which 11 healthy participants underwent head-down tilt bed rest, mimicking microgravity-induced cephalad fluid shifts, combined with elevated ambient CO2 levels similar to those on the ISS (HDT+CO2). As part of that study, we examined the effects of HDT+CO2 on cerebral perfusion. METHODS: Using arterial spin labeling, we compared cerebral perfusion before, during, and after HDT+CO2 in participants who developed SANS (n = 5) with those who did not (n = 6). RESULTS: All participants demonstrated a decrease in perfusion during HDT+CO2 (mean decrease of 25.1% at HDT7 and 16.2% at HDT29); however, the timing and degree of change varied between the groups. At day 7 of HDT+CO2, the SANS group experienced a greater reduction in perfusion than the non-SANS group (p =.05, 95% CI:-0.19 to 16.11, d=.94, large effect). Conversely, by day 29 of HDT+CO2, the SANS group had significantly higher perfusion (approaching their baseline) than the non-SANS group (p = .04, 95% CI:0.33 to 13.07, d=1.01, large effect). CONCLUSION: Compared with baseline and recovery, HDT+CO2 resulted in reduced cerebral perfusion which varied based on SANS status. Further studies are needed to unravel the relative role of HDT vs hypercapnia, to determine if these perfusion changes are clinically relevant, and whether perfusion changes contribute to the development of SANS during spaceflight.

A Prospective Study of the Causes of Bruises in Premobile Infants.

OBJECTIVE: This study had 2 objectives. First, to determine the behavior of physicians evaluating premobile infants with bruises. Second, and most importantly, to learn whether infants with unexplained bruising who had been initially evaluated by primary care and emergency department (ED) physicians are as likely to have their bruises attributed to child abuse as those children evaluated by child abuse physicians. METHODS: Primary care, ED, and child abuse pediatricians (CAPs) in King County, Washington, San Mateo, Calif, Albuquerque, NM, La Crosse, Wis, and Torrance, Calif prospectively identified and studied infants younger than 6 months with less than 6 bruises, which were judged by the evaluating clinician to be explained or unexplained after their initial clinical examination. RESULTS: Between March 1, 2010, and March 1, 2017, 63 infants with initially explained and 46 infants with initially unexplained bruises were identified. Infants with unexplained bruises had complete coagulation and abuse evaluations less frequently if they were initially identified by primary care pediatricians or ED providers than by CAPs. After imaging, laboratory, and follow-up, 54.2% (26) of the infants with initially unexplained bruises, including 2 who had been initially diagnosed with accidental injuries, were diagnosed as abused. Three (6.2%) infants had accidental bruising, 6 (12.4%) abuse mimics, 1 (2.5%) self-injury, 1 (2.5%) medical injury, and 11 (22.9%) remained of unknown causation. None had causal coagulation disorders. A total of 65.4% of the 26 abused infants had occult injuries detected by their imaging and laboratory evaluations. Six (23.1%) abused infants were not diagnosed until after they sustained subsequent injuries. Three (11.5%) were recognized abused by police investigation alone. Thirty-eight percent of the abused, bruised infants had a single bruise. Clinicians' estimates of abuse likelihood based on their initial clinical evaluation were inaccurate. Primary care, ED, and child abuse physicians identified abused infants at similar rates. CONCLUSIONS: More than half of premobile infants with initially unexplained bruises were found to be abused. Abuse was as likely for infants identified by primary care and ED providers as for those identified by CAPs. Currently, physicians often do not obtain full abuse evaluations in premobile infants with unexplained bruising. Their initial clinical judgment about abuse likelihood was inadequate. Bruised infants often have clinically occult abusive injuries or will sustain subsequent serious abuse. Bruised infants should have full abuse evaluations and referral for Protective Services and police assessments.

A novel nucleoid-associated protein coordinates chromosome replication and chromosome partition.

We searched for regulators of chromosome replication in the cell cycle model Caulobacter crescentus and found a novel DNA-binding protein (GapR) that selectively aids the initiation of chromosome replication and the initial steps of chromosome partitioning. The protein binds the chromosome origin of replication (Cori) and has higher-affinity binding to mutated Cori-DNA that increases Cori-plasmid replication in vivo. gapR gene expression is essential for normal rapid growth and sufficient GapR levels are required for the correct timing of chromosome replication. Whole genome ChIP-seq identified dynamic DNA-binding distributions for GapR, with the strongest associations at the partitioning (parABS) locus near Cori. Using molecular-genetic and fluorescence microscopy experiments, we showed that GapR also promotes the first steps of chromosome partitioning, the initial separation of the duplicated parS loci following replication from Cori. This separation occurs before the parABS-dependent partitioning phase. Therefore, this early separation, whose mechanisms is not known, coincides with the poorly defined mechanism(s) that establishes chromosome asymmetry: C. crescentus chromosomes are partitioned to distinct cell-poles which develop into replicating and non-replicating cell-types. We propose that GapR coordinates chromosome replication with asymmetry-establishing chromosome separation, noting that both roles are consistent with the phylogenetic restriction of GapR to asymmetrically dividing bacteria.

Specific and non-specific interactions of ParB with DNA: implications for chromosome segregation.

The segregation of many bacterial chromosomes is dependent on the interactions of ParB proteins with centromere-like DNA sequences called parS that are located close to the origin of replication. In this work, we have investigated the binding of Bacillus subtilis ParB to DNA in vitro using a variety of biochemical and biophysical techniques. We observe tight and specific binding of a ParB homodimer to the parS sequence. Binding of ParB to non-specific DNA is more complex and displays apparent positive co-operativity that is associated with the formation of larger, poorly defined, nucleoprotein complexes. Experiments with magnetic tweezers demonstrate that non-specific binding leads to DNA condensation that is reversible by protein unbinding or force. The condensed DNA structure is not well ordered and we infer that it is formed by many looping interactions between neighbouring DNA segments. Consistent with this view, ParB is also able to stabilize writhe in single supercoiled DNA molecules and to bridge segments from two different DNA molecules in trans. The experiments provide no evidence for the promotion of non-specific DNA binding and/or condensation events by the presence of parS sequences. The implications of these observations for chromosome segregation are discussed.

The Influence of Provider Communication Behaviors on Parental Vaccine Acceptance and Visit Experience.

OBJECTIVES: We investigated how provider vaccine communication behaviors influence parental vaccination acceptance and visit experience. METHODS: In a cross-sectional observational study, we videotaped provider-parent vaccine discussions (n = 111). We coded visits for the format providers used for initiating the vaccine discussion (participatory vs presumptive), parental verbal resistance to vaccines after provider initiation (yes vs no), and provider pursuit of recommendations in the face of parental resistance (pursuit vs mitigated or no pursuit). Main outcomes were parental verbal acceptance of recommended vaccines at visit's end (all vs ≥ 1 refusal) and parental visit experience (highly vs lower rated). RESULTS: In multivariable models, participatory (vs presumptive) initiation formats were associated with decreased odds of accepting all vaccines at visit's end (adjusted odds ratio [AOR] = 0.04; 95% confidence interval [CI] = 0.01, 0.15) and increased odds of a highly rated visit experience (AOR = 17.3; 95% CI = 1.5, 200.3). CONCLUSIONS: In the context of 2 general communication formats used by providers to initiate vaccine discussions, there appears to be an inverse relationship between parental acceptance of vaccines and visit experience. Further exploration of this inverse relationship in longitudinal studies is needed.

Communication practices and antibiotic use for acute respiratory tract infections in children.

PURPOSE: This study examined relationships between provider communication practices, antibiotic prescribing, and parent care ratings during pediatric visits for acute respiratory tract infection (ARTI). METHODS: A cross-sectional study was conducted of 1,285 pediatric visits motivated by ARTI symptoms. Children were seen by 1 of 28 pediatric providers representing 10 practices in Seattle, Washington, between December 2007 and April 2009. Providers completed post-visit surveys reporting on children's presenting symptoms, physical examination findings, assigned diagnoses, and treatments prescribed. Parents completed post-visit surveys reporting on provider communication practices and care ratings for the visit. Multivariate analyses identified key predictors of prescribing antibiotics for ARTI and of parent visit ratings. RESULTS: Suggesting actions parents could take to reduce their child's symptoms (providing positive treatment recommendations) was associated with decreased risk of antibiotic prescribing whether done alone or in combination with negative treatment recommendations (ruling out the need for antibiotics) [adjusted risk ratio (aRR) 0.48; 95% CI, 0.24-0.95; and aRR 0.15; 95% CI, 0.06-0.40, respectively]. Parents receiving combined positive and negative treatment recommendations were more likely to give the highest possible visit rating (aRR 1.16; 95% CI, 1.01-1.34). CONCLUSION: Combined use of positive and negative treatment recommendations may reduce the risk of antibiotic prescribing for children with viral ARTIs and at the same time improve visit ratings. With the growing threat of antibiotic resistance at the community and individual level, these communication techniques may assist frontline providers in helping to address this pervasive public health problem.

A proteomics approach to isolating neuropilin-dependent α5 integrin trafficking pathways: neuropilin 1 and 2 co-traffic α5 integrin through endosomal p120RasGAP to promote polarised fibronectin fibrillogenesis in endothelial cells.

Integrin trafficking to and from membrane adhesions is a crucial mechanism that dictates many aspects of a cell's behaviour, including motility, polarisation, and invasion. In endothelial cells (ECs), the intracellular traffic of α5 integrin is regulated by both neuropilin 1 (NRP1) and neuropilin 2 (NRP2), yet the redundancies in function between these co-receptors remain unclear. Moreover, the endocytic complexes that participate in NRP-directed traffic remain poorly annotated. Here we identify an important role for the GTPase-activating protein p120RasGAP in ECs, promoting the recycling of α5 integrin from early endosomes. Mechanistically, p120RasGAP enables transit of endocytosed α5 integrin-NRP1-NRP2 complexes to Rab11+ recycling endosomes, promoting cell polarisation and fibronectin (FN) fibrillogenesis. Silencing of both NRP receptors, or p120RasGAP, resulted in the accumulation of α5 integrin in early endosomes, a loss of α5 integrin from surface adhesions, and attenuated EC polarisation. Endothelial-specific deletion of both NRP1 and NRP2 in the postnatal retina recapitulated our in vitro findings, severely impairing FN fibrillogenesis and polarised sprouting. Our data assign an essential role for p120RasGAP during integrin traffic in ECs and support a hypothesis that NRP receptors co-traffic internalised cargoes. Importantly, we utilise comparative proteomics analyses to isolate a comprehensive map of NRP1-dependent and NRP2-dependent α5 integrin interactions in ECs.

The Caulobacter crescentus chromosome replication origin evolved two classes of weak DnaA binding sites.

The Caulobacter crescentus replication initiator DnaA and essential response regulator CtrA compete to control chromosome replication. The C. crescentus replication origin (Cori) contains five strong CtrA binding sites but only two apparent DnaA boxes, termed G-boxes (with a conserved second position G, TGATCCACA). Since clusters of DnaA boxes typify bacterial replication origins, this discrepancy suggested that C. crescentus DnaA recognizes different DNA sequences or compensates with novel DNA-binding proteins. We searched for novel DNA sites by scanning mutagenesis of the most conserved Cori DNA. Autonomous replication assays showed that G-boxes and novel W-boxes (TCCCCA) are essential for replication. Further analyses showed that C. crescentus DnaA binds G-boxes with moderate and W-boxes with very weak affinities significantly below DnaA's capacity for high-affinity Escherichia coli-boxes (TTATCCACA). Cori has five conserved W-boxes. Increasing W-box affinities increases or decreases autonomous replication depending on their strategic positions between the G-boxes. In vitro, CtrA binding displaces DnaA from proximal G-boxes and from distal W-boxes implying CtrA-DnaA competition and DnaA-DnaA cooperation between G-boxes and W-boxes. Similarly, during cell cycle progression, CtrA proteolysis coincides with DnaA binding to Cori. We also observe highly conserved W-boxes in other replication origins lacking E. coli-boxes. Therefore, strategically weak DnaA binding can be a general means of replication control.

Using Immortalized Endothelial Cells to Study the Roles of Adhesion Molecules in VEGF-Induced Signaling.

The ability to study the role of specific genes in endothelial cell biology is made possible by our ability to modulate their expression through siRNA or knockout technologies. However, many in vitro protocols, particularly those of a biochemical nature, require large numbers of endothelial cells. These types of analyses are encumbered by the need to repeatedly produce and characterize primary endothelial cell cultures and can be greatly facilitated by the use of immortalized microvascular endothelial cells. However, we have found that the manipulation of gene expression in these cells is not always straight forward. Here we describe how we alter gene expression in polyoma middle T antigen immortalized microvascular endothelial cells isolated from wild-type and genetically modified mice to study the role of cell adhesion molecules in downstream assays.

Endothelial VEGFR Coreceptors Neuropilin-1 and Neuropilin-2 Are Essential for Tumor Angiogenesis.

Neuropilin (NRP) expression is highly correlated with poor outcome in multiple cancer subtypes. As known coreceptors for VEGFRs, core drivers of angiogenesis, past investigations have alluded to their functional roles in facilitating tumorigenesis by promoting invasive vessel growth. Despite this, it remains unclear as to whether NRP1 and NRP2 act in a synergistic manner to enhance pathologic angiogenesis. Here we demonstrate, using NRP1 ECKO , NRP2 ECKO , and NRP1/NRP2 ECKO mouse models, that maximum inhibition of primary tumor development and angiogenesis is achieved when both endothelial NRP1 and NRP2 are targeted simultaneously. Metastasis and secondary site angiogenesis were also significantly inhibited in NRP1/NRP2 ECKO animals. Mechanistic studies revealed that codepleting NRP1 and NRP2 in mouse-microvascular endothelial cells stimulates rapid shuttling of VEGFR-2 to Rab7+ endosomes for proteosomal degradation. Our results highlight the importance of targeting both NRP1 and NRP2 to modulate tumor angiogenesis. Significance: The findings presented in this study demonstrate that tumor angiogenesis and growth can be arrested completely by cotargeting endothelial NRP1 and NRP2. We provide new insight into the mechanisms of action regulating NRP-dependent tumor angiogenesis and signpost a novel approach to halt tumor progression.

Contaminating transfection complexes can masquerade as small extracellular vesicles and impair their delivery of RNA.

One of the functions of small extracellular vesicles (sEVs) which has received the most attention is their capacity to deliver RNA into the cytoplasm of target cells. These studies have often been performed by transfecting RNAs into sEV-producing cells, to later purify and study sEV delivery of RNA. Transfection complexes and other delivery vehicles accumulate in late endosomes where sEV are formed and over 50% of transfection complexes or delivery vehicles administered to cells are released again to the extracellular space by exocytosis. This raises the possibility that transfection complexes could alter sEVs and contaminate sEV preparations. We found that widely used transfection reagents including RNAiMax and INTERFERin accumulated in late endosomes. These transfection complexes had a size similar to sEV and were purified by ultracentrifugation like sEV. Focusing on the lipid-based transfection reagent RNAiMax, we found that preparations of sEV from transfected cells contained lipids from transfection complexes and transfected siRNA was predominantly in particles with the density of transfection complexes, rather than sEV. This suggests that transfection complexes, such as lipid-based RNAiMax, may frequently contaminate sEV preparations and could account for some reports of sEV-mediated delivery of nucleic acids. Transfection of cells also impaired the capacity of sEVs to deliver stably-expressed siRNAs, suggesting that transfection of cells may alter sEVs and prevent the study of their endogenous capacity to deliver RNA to target cells.

Prospective validation of smartphone-based heart rate and respiratory rate measurement algorithms.

Background: Measuring vital signs plays a key role in both patient care and wellness, but can be challenging outside of medical settings due to the lack of specialized equipment. Methods: In this study, we prospectively evaluated smartphone camera-based techniques for measuring heart rate (HR) and respiratory rate (RR) for consumer wellness use. HR was measured by placing the finger over the rear-facing camera, while RR was measured via a video of the participants sitting still in front of the front-facing camera. Results: In the HR study of 95 participants (with a protocol that included both measurements at rest and post exercise), the mean absolute percent error (MAPE) ± standard deviation of the measurement was 1.6% ± 4.3%, which was significantly lower than the pre-specified goal of 5%. No significant differences in the MAPE were present across colorimeter-measured skin-tone subgroups: 1.8% ± 4.5% for very light to intermediate, 1.3% ± 3.3% for tan and brown, and 1.8% ± 4.9% for dark. In the RR study of 50 participants, the mean absolute error (MAE) was 0.78 ± 0.61 breaths/min, which was significantly lower than the pre-specified goal of 3 breaths/min. The MAE was low in both healthy participants (0.70 ± 0.67 breaths/min), and participants with chronic respiratory conditions (0.80 ± 0.60 breaths/min). Conclusions: These results validate the accuracy of our smartphone camera-based techniques to measure HR and RR across a range of pre-defined subgroups.

A mobile-optimized artificial intelligence system for gestational age and fetal malpresentation assessment.

Background: Fetal ultrasound is an important component of antenatal care, but shortage of adequately trained healthcare workers has limited its adoption in low-to-middle-income countries. This study investigated the use of artificial intelligence for fetal ultrasound in under-resourced settings. Methods: Blind sweep ultrasounds, consisting of six freehand ultrasound sweeps, were collected by sonographers in the USA and Zambia, and novice operators in Zambia. We developed artificial intelligence (AI) models that used blind sweeps to predict gestational age (GA) and fetal malpresentation. AI GA estimates and standard fetal biometry estimates were compared to a previously established ground truth, and evaluated for difference in absolute error. Fetal malpresentation (non-cephalic vs cephalic) was compared to sonographer assessment. On-device AI model run-times were benchmarked on Android mobile phones. Results: Here we show that GA estimation accuracy of the AI model is non-inferior to standard fetal biometry estimates (error difference -1.4 ± 4.5 days, 95% CI -1.8, -0.9, n = 406). Non-inferiority is maintained when blind sweeps are acquired by novice operators performing only two of six sweep motion types. Fetal malpresentation AUC-ROC is 0.977 (95% CI, 0.949, 1.00, n = 613), sonographers and novices have similar AUC-ROC. Software run-times on mobile phones for both diagnostic models are less than 3 s after completion of a sweep. Conclusions: The gestational age model is non-inferior to the clinical standard and the fetal malpresentation model has high AUC-ROCs across operators and devices. Our AI models are able to run on-device, without internet connectivity, and provide feedback scores to assist in upleveling the capabilities of lightly trained ultrasound operators in low resource settings.

Development of a survey to identify vaccine-hesitant parents: the parent attitudes about childhood vaccines survey.

OBJECTIVE: To develop a survey to accurately assess parental vaccine hesitancy. RESULTS: The initial survey contained 17 items in four content domains: (1) immunization behavior; (2) beliefs about vaccine safety and efficacy; (3) attitudes about vaccine mandates and exemptions; and (4) trust. Focus group data yielded an additional 10 survey items. Expert review of the survey resulted in the deletion of nine of 27 items and revisions to 11 of the remaining 18 survey items. Parent pretesting resulted in the deletion of one item, the addition of one item, the revision of four items, and formatting changes to enhance usability. The final survey contains 18 items in the original four content domains. METHODS: An iterative process was used to develop the survey. First, we reviewed previous studies and surveys on parental health beliefs regarding vaccination to develop content domains and draft initial survey items. Focus groups of parents and pediatricians generated additional themes and survey items. Six immunization experts reviewed the items in the resulting draft survey and ranked them on a 1-5 scale for significance in identifying vaccine-hesitant parents (5 indicative of a highly significant item). The lowest third of ranked items were dropped. The revised survey was pretested with 25 parents to assess face validity, usability and item understandability. CONCLUSIONS: The Parent Attitudes about Childhood Vaccines survey was constructed using qualitative methodology to identify vaccine-hesitant parents and has content and face validity. Further psychometric testing is needed.

Homeopathic ear drops as an adjunct to standard therapy in children with acute otitis media.

OBJECTIVE: To assess the effectiveness of a homeopathic ear drop for treatment of otalgia in children with acute otitis media (AOM). METHODS: Children with AOM were enrolled in the study at the time of diagnosis and randomized to receive either standard therapy alone or standard therapy plus a homeopathic ear drop solution that was to be used on as needed basis for up to 5 days. Parents of children in both treatment groups rated the severity of 5 AOM symptoms twice daily for 5 days in a symptom diary. A symptom score was computed for each assessment with lower scores denoting less severe symptoms. Parents of children randomized to receive ear drops also recorded information regarding symptoms being treated and response to treatment. RESULTS: A total of 119 eligible children were enrolled in the study; symptom diaries were received from 94 (79%). Symptom scores tended to be lower in the group of children receiving ear drops than in those receiving standard therapy alone; these differences were significant at the second and third assessments (P = 0.04 and P = 0.003, respectively). In addition, the rate of symptom improvement was faster in children in the ear drop group compared with children in standard therapy alone group (P = 0.002). The most common reason for administration of ear drops was ear pain, recorded for 93 doses; improvement was noted after 78.4% of doses for this indication. There were no significant side effects related to use of the ear drops. CONCLUSIONS: This study suggests that homeopathic ear drops were moderately effective in treating otalgia in children with AOM and may be most effective in the early period after a diagnosis of AOM. Pediatricians and other primary health care providers should consider homeopathic ear drops a useful adjunct to standard therapy.

CTP and parS coordinate ParB partition complex dynamics and ParA-ATPase activation for ParABS-mediated DNA partitioning.

ParABS partition systems, comprising the centromere-like DNA sequence parS, the parS-binding ParB-CTPase, and the nucleoid-binding ParA-ATPase, ensure faithful segregation of bacterial chromosomes and low-copy-number plasmids. F-plasmid partition complexes containing ParBF and parSF move by generating and following a local concentration gradient of nucleoid-bound ParAF. However, the process through which ParBF activates ParAF-ATPase has not been defined. We studied CTP- and parSF-modulated ParAF-ParBF complex assembly, in which DNA-bound ParAF-ATP dimers are activated for ATP hydrolysis by interacting with two ParBF N-terminal domains. CTP or parSF enhances the ATPase rate without significantly accelerating ParAF-ParBF complex assembly. Together, parSF and CTP accelerate ParAF-ParBF assembly without further significant increase in ATPase rate. Magnetic-tweezers experiments showed that CTP promotes multiple ParBF loading onto parSF-containing DNA, generating condensed partition complex-like assemblies. We propose that ParBF in the partition complex adopts a conformation that enhances ParBF-ParBF and ParAF-ParBF interactions promoting efficient partitioning.

Comparison of Dural Venous Sinus Volumes Before and After Flight in Astronauts With and Without Spaceflight-Associated Neuro-Ocular Syndrome.

Importance: Spaceflight-associated neuro-ocular syndrome (SANS) occurs in 40% to 60% of National Aeronautics and Space Administration (NASA) International Space Station (ISS) astronauts who present postflight with ophthalmological findings and elevated intracranial pressure. The etiology of SANS is unknown; it is hypothesized that venous outflow congestion from the head and neck occurs because of microgravity, which is supported by the finding of internal jugular vein stagnant flow and thrombosis in some astronauts, but the impact on intracranial dural venous sinus structures remains unknown. Objectives: To clarify the potential risk of retrograde extension of clot intracranially among astronauts with internal jugular venous thrombosis by evaluating intracranial venous structures following spaceflight and to assess for any association between intracranial venous congestion and SANS. Design, Setting, and Participants: This retrospective cohort study of all NASA astronauts who had undergone magnetic resonance (MR) venography at the time of the study included quantitative and qualitative assessments of the intracranial venous system on preflight and postflight MR venograms. Data were collected a mean (SD) of 525.8 (187.5) days before spaceflight and 2.0 (1.5) days after return to Earth. A semiautomated segmentation of the venogram images was used, which was then compared with a neuroradiologist's assessment. Exposures: A mean (SD) 184.3 (66.0) days of ISS spaceflight missions. Main Outcomes and Measures: Dural venous sinus volumes before and after spaceflight. Results: A total of 12 astronauts (2 [16.67%] women; 10 [83.33%] men), with a mean (SD) age of 47.8 (5.8) years, were included. Overall, 4 astronauts (33.33%) met the diagnostic criteria for SANS. No dural venous sinus thrombosis was detected for any astronaut. Astronauts with SANS had significantly greater median (range) preflight to postflight increases in volume vs astronauts without SANS for all 3 venous sinus structures: superior sagittal sinus (13.40% [8.70% to 17.47%] vs -2.66% [-15.84% to 5.31%,]; P = .004), right transverse/sigmoid sinus (17.15% [7.63% to 30.08%] vs 0.77% [-14.98% to 15.12%]; P = .02), and left transverse/sigmoid sinus (9.40% [5.20% to 15.50%] vs -1.40% [-14.20% to 12.50%]; P = .03). There was a positive correlation between the neuroradiologist's evaluation and the semiautomated method for the superior sagittal sinus (rpb = 0.64; P = .02) and the right transverse/sigmoid sinus (rpb = 0.58; P = .050). Conclusions and Relevance: These findings, in conjunction with the growing body of evidence of abnormal blood flow dynamics during spaceflight, suggest an association between intracranial venous congestion and SANS. Thus, there is an implication that individuals with increased venous sinus compliance may be at increased risk of developing SANS. These findings should be confirmed in a larger astronaut population and may contribute to understanding disorders of intracranial venous outflow on Earth.