Cultivation of the causative agent of human neoehrlichiosis from clinical isolates identifies vascular endothelium as a target of infection

ABSTRACTCandidatus (Ca.) Neoehrlichia mikurensis is the cause of neoehrlichiosis, an emerging tick-borne infectious disease characterized by fever and vascular events. The bacterium belongs to the Anaplasmataceae, a family of obligate intracellular pathogens, but has not previously been cultivated, and it is uncertain which cell types it infects. The goals of this study were to cultivate Ca. N. mikurensis in cell lines and to identify possible target cells for human infection. Blood components derived from infected patients were inoculated into cell lines of both tick and human origin. Bacterial growth in the cell cultures was monitored by real-time PCR and imaging flow cytometry. Ca. N. mikurensis was successfully propagated from the blood of immunocompromised neoehrlichiosis patients in two Ixodes spp. tick cell lines following incubation periods of 7–20 weeks. Human primary endothelial cells derived from skin microvasculature as well as pulmonary artery were also susceptible to infection with tick cell-derived bacteria. Finally, Ca. N. mikurensis was visualized within circulating endothelial cells of two neoehrlichiosis patients. To conclude, we report the first successful isolation and propagation of Ca. N. mikurensis from clinical isolates and identify human vascular endothelial cells as a target of infection

What can eye-tracking tell us?

Background: Early development of neurocognitive functions in infants can be compromised by poverty, malnutrition and lack of adequate stimulation. Optimal management of neurodevelopmental problems in infants requires assessment tools that can be used early in life, and are objective and applicable across economic, cultural and educational settings. Objective and design: The present study examined the feasibility of infrared eye tracking as a novel and highly automated technique for assessing visual-orienting and sequence-learning abilities as well as attention to facial expressions in young (9-month-old) infants. Techniques piloted in a high-resource laboratory setting in Finland (N=39) were subsequently field-tested in a community health centre in rural Malawi (N=40). Results: Parents' perception of the acceptability of the method (Finland 95%, Malawi 92%) and percentages of infants completing the whole eye-tracking test (Finland 95%, Malawi 90%) were high, and percentages of valid test trials (Finland 69-85%, Malawi 68-73%) satisfactory at both sites. Test completion rates were slightly higher for eye tracking (90%) than traditional observational tests (87%) in Malawi. The predicted response pattern indicative of specific cognitive function was replicated in Malawi, but Malawian infants exhibited lower response rates and slower processing speed across tasks. Conclusions: High test completion rates and the replication of the predicted test patterns in a novel environment in Malawi support the feasibility of eye tracking as a technique for assessing infant development in low-resource setting. Further research is needed to the test-retest stability and predictive validity of the eye-tracking scores in low-income settings

Training attention control of very preterm infants: protocol for a feasibility study of the Attention Control Training (ACT)

Background Children born preterm may display cognitive, learning, and behaviour difficulties as they grow up. In particular, very premature birth (gestation age between 28 and less than 32 weeks) may put infants at increased risk of intellectual deficits and attention deficit disorder. Evidence suggests that the basis of these problems may lie in difficulties in the development of executive functions. One of the earliest executive functions to emerge around 1 year of age is the ability to control attention. An eye-tracking-based cognitive training programme to support this emerging ability, the Attention Control Training (ACT), has been developed and tested with typically developing infants. The aim of this study is to investigate the feasibility of using the ACT with healthy very preterm (VP) infants when they are 12 months of age (corrected age). The ACT has the potential to address the need for supporting emerging cognitive abilities of VP infants with an early intervention, which may capitalise on infants’ neural plasticity. Methods/design The feasibility study is designed to investigate whether it is possible to recruit and retain VP infants and their families in a randomised trial that compares attention and social attention of trained infants against those that are exposed to a control procedure. Feasibility issues include the referral/recruitment pathway, attendance, and engagement with testing and training sessions, completion of tasks, retention in the study, acceptability of outcome measures, quality of data collected (particularly, eye-tracking data). The results of the study will inform the development of a larger randomised trial. Discussion Several lines of evidence emphasise the need to support emerging cognitive and learning abilities of preterm infants using early interventions. However, early interventions with preterm infants, and particularly very preterm ones, face difficulties in recruiting and retaining participants. These problems are also augmented by the health vulnerability of this population. This feasibility study will provide the basis for informing the implementation of an early cognitive intervention for very preterm infants. Trial registration Registered Registration ID: NCT03896490. Retrospectively registered at Clinical Trials Protocol Registration and Results System (clinicaltrials.gov)

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention

Serological reactivity to Anaplasma phagocytophilumin neoehrlichiosis patients

AbstractThe tick-borne bacterium Candidatus (Ca.) Neoehrlichia (N.) mikurensis is a cause of Bfever of unknown origin^ because thisstrict intracellular pathogen escapes detection by routine blood cultures. Case reports suggest that neoehrlichiosis patients maydisplay serological reactivity to Anaplasma (A.) phagocytophilum. Since Anaplasma serology is part of the diagnostic work-up ofundetermined fever in European tick-exposed patients, we wanted to investigate (1) the prevalence of A. phagocytophilumseropositivity among neoehrlichiosis patients, (2) the frequency of misdiagnosed neoehrlichiosis patients among A.phagocytophilum seropositive patients, and (3) the frequency of A. phagocytophilum and Ca. N. mikurensis co-infections.Neoehrlichiosis patients (n = 18) were analyzed for A. phagocytophilum IgM and IgG serum antibodies by indirect immunofluorescenceassay. Serum samples from suspected anaplasmosis patients (n = 101) were analyzed for bacterial DNA contents bysingleplex PCR specific for A. phagocytophilum and Ca. N. mikurensis, respectively. One fifth of the neoehrlichiosis patients (4/18) were seropositive for IgM and/or IgG to A. phagocytophilum at the time of diagnosis. Among the patients with suspectedanaplasmosis, 2% (2/101) were positive for Ca. N. mikurensis by PCR whereas none (0/101) had detectable A. phagocytophilumDNA in the serum. To conclude, patients with suspected anaplasmosis may in fact have neoehrlichiosis.We found no evidence ofA. phagocytophilum and Ca. N. mikurensis co-infections in humans with suspected anaplasmosis or confirmed neoehrlichiosis

Robustness and Precision : How Data Quality May Influence Key Dependent Variables in Infant Eye-Tracker Analyses

In recent years, eye-tracking has become a popular method for drawing conclusions about infant cognition. Relatively little attention has been paid, however, to methodological issues associated with infant eye-tracking. Here, we consider the possibility that systematic differences in the quality of raw eye-tracking data obtained from different populations and individuals might create the impression of differences in gaze behavior, without this actually being the case. First, we show that lower quality eye-tracking data are obtained from populations who are younger and populations who are more fidgety and that data quality declines during the testing session. Second, we assess how these differences in data quality might influence key dependent variables in eye-tracking analyses. We show that lower precision data can appear to suggest a reduced likelihood to look at the eyes in a face relative to the mouth. We also show that less robust tracking may manifest as slower reaction time latencies (e.g., time to first fixation). Finally, we show that less robust data can manifest as shorter first look/visit duration. We argue that data quality should be reported in all analyses of infant eye-tracking data and/or that steps should be taken to control for data quality before performing final analyses

Robustness and Precision : How Data Quality May Influence Key Dependent Variables in Infant Eye-Tracker Analyses

In recent years, eye-tracking has become a popular method for drawing conclusions about infant cognition. Relatively little attention has been paid, however, to methodological issues associated with infant eye-tracking. Here, we consider the possibility that systematic differences in the quality of raw eye-tracking data obtained from different populations and individuals might create the impression of differences in gaze behavior, without this actually being the case. First, we show that lower quality eye-tracking data are obtained from populations who are younger and populations who are more fidgety and that data quality declines during the testing session. Second, we assess how these differences in data quality might influence key dependent variables in eye-tracking analyses. We show that lower precision data can appear to suggest a reduced likelihood to look at the eyes in a face relative to the mouth. We also show that less robust tracking may manifest as slower reaction time latencies (e.g., time to first fixation). Finally, we show that less robust data can manifest as shorter first look/visit duration. We argue that data quality should be reported in all analyses of infant eye-tracking data and/or that steps should be taken to control for data quality before performing final analyses

Widely applicable MATLAB routines for automated analysis of saccadic reaction times

Saccadic reaction time (SRT) is a widely used dependent variable in eye-tracking studies of human cognition and its disorders. SRTs are also frequently measured in studies with special populations, such as infants and young children, who are limited in their ability to follow verbal instructions and remain in a stable position over time. In this article, we describe a library of MATLAB routines (Mathworks, Natick, MA) that are designed to (1) enable completely automated implementation of SRT analysis for multiple data sets and (2) cope with the unique challenges of analyzing SRTs from eye-tracking data collected from poorly cooperating participants. The library includes preprocessing and SRT analysis routines. The preprocessing routines (i.e., moving median filter and interpolation) are designed to remove technical artifacts and missing samples from raw eye-tracking data. The SRTs are detected by a simple algorithm that identifies the last point of gaze in the area of interest, but, critically, the extracted SRTs are further subjected to a number of postanalysis verification checks to exclude values contaminated by artifacts. Example analyses of data from 5- to 11-month-old infants demonstrated that SRTs extracted with the proposed routines were in high agreement with SRTs obtained manually from video records, robust against potential sources of artifact, and exhibited moderate to high test-retest stability. We propose that the present library has wide utility in standardizing and automating SRT-based cognitive testing in various populations. The MATLAB routines are open source and can be downloaded from http://www.uta.fi/med/icl/methods.html

Widely applicable MATLAB routines for automated analysis of saccadic reaction times

Saccadic reaction time (SRT) is a widely used dependent variable in eye-tracking studies of human cognition and its disorders. SRTs are also frequently measured in studies with special populations, such as infants and young children, who are limited in their ability to follow verbal instructions and remain in a stable position over time. In this article, we describe a library of MATLAB routines (Mathworks, Natick, MA) that are designed to (1) enable completely automated implementation of SRT analysis for multiple data sets and (2) cope with the unique challenges of analyzing SRTs from eye-tracking data collected from poorly cooperating participants. The library includes preprocessing and SRT analysis routines. The preprocessing routines (i.e., moving median filter and interpolation) are designed to remove technical artifacts and missing samples from raw eye-tracking data. The SRTs are detected by a simple algorithm that identifies the last point of gaze in the area of interest, but, critically, the extracted SRTs are further subjected to a number of postanalysis verification checks to exclude values contaminated by artifacts. Example analyses of data from 5- to 11-month-old infants demonstrated that SRTs extracted with the proposed routines were in high agreement with SRTs obtained manually from video records, robust against potential sources of artifact, and exhibited moderate to high test-retest stability. We propose that the present library has wide utility in standardizing and automating SRT-based cognitive testing in various populations. The MATLAB routines are open source and can be downloaded from http://www.uta.fi/med/icl/methods.html