Production of extracellular vesicles from equine embryo-derived mesenchymal stromal cells

In brief

Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have shown promise as off-the-shelf therapeutics; however, producing them in sufficient quantities can be challenging. In this study, MSCs were isolated from preimplantation equine embryos and used to produce EVs in two commercially available bioreactor designs.

Abstract

Mesenchymal stromal cells (MSC) have recently been explored for their potential use as therapeutics in human and veterinary medicine applications, such as the treatment of endometrial inflammation and infertility. Allogeneic MSC-derived extracellular vesicles (EVs) may also provide therapeutic benefits with advantage of being an 'off-the-shelf' solution, provided they can be produced in large enough quantities, without contamination from bovine EVs contained in fetal bovine serum that is a common component of cell culture media. Toward this aim, we demonstrated the successful isolation and characterization of equine MSCs from preimplantation embryos. We also demonstrate that many of these lines can be propagated long-term in culture while retaining their differentiation potential and conducted a head-to-head comparison of two bioreactor systems for scalable EV production including in serum-free conditions. Based on our findings, the CELLine AD 1000 flasks enabled higher cell density cultures and significantly more EV production than the FiberCell system or conventional culture flasks. These findings will enable future isolation of equine MSCs and the scalable culture of their EVs for a wide range of applications in this rapidly growing field.

Keyworker mediated enhancement of physical health in patients with first episode psychosis: A feasibility/acceptability study

AIM

Early intervention for people experiencing first episode psychosis is a priority, and keyworkers are vital to such services. However, keyworkers' roles in addressing first episode psychosis patients' physical health are under researched. This study addresses this knowledge gap by evaluating a keyworker-mediated intervention promoting physical health among first episode psychosis patients.

METHODS

The study was informed by the Medical Research Council's Framework for Complex Interventions to Improve Health. First episode psychosis participants were recruited from three Irish mental health services. The intervention was evaluated in terms of its feasibility/acceptability.

RESULTS

Feasibility outcomes were mixed (recruitment rate = 24/68 [35.3%]; retention rate = 18/24 [75%]). The baseline sample was predominantly male (M:F ratio = 13:6; Med age = 25 y; IQR = 23-42 y). Common health issues among participants included overweightness/obesity (n = 11) and substance use (smoking/alcohol consumption [n = 19]). Participants' initial health priorities included exercising more (n = 10), improving diet (n = 6), weight loss (n = 7) and using various health/healthcare services. The intervention's acceptability was evidenced by the appreciation participants had for physical health keyworkers' support, as well as the healthy lifestyle, which the intervention promoted. Acceptability was somewhat compromised by a low-recruitment rate, variable linkages between keyworkers and general practitioners (GPs) and COVID-19 restrictions.

CONCLUSIONS

Physical health-oriented keyworker interventions for first episode psychosis patients show promise and further evaluation of such initiatives is warranted. Future interventions should be mindful of participant recruitment challenges, strategies to enhance relationships between keyworkers and GPs, and if necessary, they should mitigate COVID-19 restrictions' impacts on care.

Plasma Neurofilament Light for Prediction of Disease Progression in Familial Frontotemporal Lobar Degeneration

OBJECTIVE

We tested the hypothesis that plasma neurofilament light chain (NfL) identifies asymptomatic carriers of familial frontotemporal lobar degeneration (FTLD)-causing mutations at risk of disease progression.

METHODS

Baseline plasma NfL concentrations were measured with single-molecule array in original (n = 277) and validation (n = 297) cohorts. C9orf72, GRN, and MAPT mutation carriers and noncarriers from the same families were classified by disease severity (asymptomatic, prodromal, and full phenotype) using the CDR Dementia Staging Instrument plus behavior and language domains from the National Alzheimer's Disease Coordinating Center FTLD module (CDR+NACC-FTLD). Linear mixed-effect models related NfL to clinical variables.

RESULTS

In both cohorts, baseline NfL was higher in asymptomatic mutation carriers who showed phenoconversion or disease progression compared to nonprogressors (original: 11.4 ± 7 pg/mL vs 6.7 ± 5 pg/mL, p = 0.002; validation: 14.1 ± 12 pg/mL vs 8.7 ± 6 pg/mL, p = 0.035). Plasma NfL discriminated symptomatic from asymptomatic mutation carriers or those with prodromal disease (original cutoff: 13.6 pg/mL, 87.5% sensitivity, 82.7% specificity; validation cutoff: 19.8 pg/mL, 87.4% sensitivity, 84.3% specificity). Higher baseline NfL correlated with worse longitudinal CDR+NACC-FTLD sum of boxes scores, neuropsychological function, and atrophy, regardless of genotype or disease severity, including asymptomatic mutation carriers.

CONCLUSIONS

Plasma NfL identifies asymptomatic carriers of FTLD-causing mutations at short-term risk of disease progression and is a potential tool to select participants for prevention clinical trials.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02372773 and NCT02365922.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in carriers of FTLD-causing mutations, elevation of plasma NfL predicts short-term risk of clinical progression.

The role of key workers in improving physical health in first episode psychosis: A scoping review

AIM

Studies have demonstrated that a majority of the decline in health status and functioning emerges during the first few years following the onset of psychosis. This knowledge led to the development of specialized early intervention services (EIS) targeting patients experiencing their first episode of psychosis (FEP). The central component of EIS is often assertive case management delivered by a multidisciplinary team, where an appointed key worker is responsible for coordinating treatment and delivering various psychosocial interventions to service users. The aim of this scoping review was to examine how key workers can enhance the physical health outcomes in people with FEP by addressing the factors associated with increased mortality in this population.

METHODS

The scoping review framework comprised a five-stage process developed by Arksey and O'Malley. The search process was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

A total of 27 studies conducted across 10 countries were analysed. These studies discussed the various ways in which key workers can mediate enhancements in the various factors contributing to the increased mortality rates in FEP patients.

CONCLUSIONS

A broad range of key worker-mediated outcomes was identified, which were broadly classified into three themes: influences on lifestyle, influences on effects of psychosis and influences on organizational barriers. Our findings suggest that key workers primarily mediated the amelioration of psychosis-induced effects and the reduction of organizational barriers. Further trials of key worker interventions to enhance physical health outcomes in this cohort are warranted.

Validation of JEFF-3.3 and ENDF/B-VIII.0 nuclear data libraries in ANSWERS codes

The JEFF-3.3 and ENDF/B-VIII.0 evaluated nuclear data libraries were released in December 2017 and February 2018 respectively. Both evaluations represent a comprehensive update to their predecessor evaluations. The ANSWERS Software Service produces the MONK® and MCBEND Monte Carlo codes, and the WIMS deterministic code for nuclear criticality, shielding and reactor physics applications. MONK and MCBEND can utilise continuous energy nuclear data provided by the BINGO nuclear data library and MONK and WIMS can utilise broad energy group data (172 group XMAS scheme) via the WIMS nuclear data library. To produce the BINGO library, the BINGO Pre-Processor code is used to process ENDF-6 format evaluations. This utilises the RECONR-BROADR-PURR sequence of NJOY2016 to reconstruct and Doppler broaden the free gas neutron cross sections together with bespoke routines to generate cumulative distributions for the S(α,β) tabulations and equi-probable bins or probability functions for the secondary angle and energy data.

To produce the WIMS library, NJOY2016 is again used to reconstruct and Doppler broaden the cross sections. The THERMR module is used to process the thermal scattering data. Preparation of data for system-dependent resonance shielding of some nuclides is performed. GROUPR is then used to produce the group averaged data before all the data are transformed into the specific WIMS library format.

The MONK validation includes analyses based on around 800 configurations for a range of fuel and moderator types. The WIMS validation includes analyses of zero-energy critical and sub-critical, commissioning, operational and post-irradiation experiments for a range of fuel and moderator types. This paper presents and discusses the results of MONK and WIMS validation benchmark calculations using the JEFF-3.3 and ENDF/B-VIII.0 based BINGO and WIMS nuclear data libraries.

Processing and application of nuclear data for low temperature criticality assessment

Until recently, criticality safety assessment codes had a minimum temperature at which calculations can be performed. Where criticality assessment has been required for lower temperatures, indirect methods, including reasoned argument or extrapolation, have been required to assess reactivity changes associated with these temperatures.

The ANSWERS Software Service MONK® version 10B Monte Carlo criticality code, is capable of performing criticality calculations at any temperature, within the temperature limits of the underlying nuclear data in the BINGO continuous energy library. The temperature range of the nuclear data has been extended below the traditional lower limit of 293.6 K to 193 K in a prototype BINGO library, primarily based on JEFF-3.1.2 data. The temperature range of the thermal bound scattering data of the key moderator materials was extended by reprocessing the NJOY LEAPR inputs used to produce bound data for JEFF-3.1.2 and ENDF/B-VIII.0. To give confidence in the low temperature nuclear data, a series of MONK and MCBEND calculations have been performed and results compared against external data sources. MCBEND is a Monte Carlo code for shielding and dosimetry and shares commonalities to its sister code MONK including the BINGO nuclear data library. Good agreement has been achieved between calculated and experimental cross sections for ice, k-effective results for low temperature criticality benchmarks and calculated and experimentally determined eigenvalues for thermal neutron diffusion in ice.

To quantify the differences between ice and water bound scattering data a number of MONK criticality calculations were performed for nuclear fuel transport flask configurations. The results obtained demonstrate good agreement with extrapolation methods. There is a discernible difference in the use of ice and water data.

Detection of mycobacterial lipoarabinomannan in serum for diagnosis of active tuberculosis

Urinary detection of Mycobacterium tuberculosis lipoarabinomannan (LAM) for tuberculosis (TB) diagnosis is well characterized, but the utility of serum LAM detection remains unclear. We developed an assay for serum LAM detection using single-molecule array (Simoa), purified M. tuberculosis LAM, and anti-LAM monoclonal antibodies and evaluated performance on diluted/heat-treated serum samples from patients with and without active TB and/or HIV. The Simoa assay had a limit of detection of 0.35 pg/mL and lower limit of quantification of 0.942 pg/mL. Corrected serum LAM concentrations ranged from 0 to 132.0 pg/mL [median 1.71, interquartile range (IQR) 0.94-6.80] in 90 TB+ patients and from 0 to 2.29 pg/mL (median 1.03, IQR 0.47-1.69) in 55 TB- patients. Using a cutoff of 2.3 pg/mL for 100% specificity, assay sensitivity was 37% in all TB+ subjects (33/90; 95% CI 0.27-0.48), 47% in TB+/HIV+ subjects (26/55; 0.34-0.61), and 60% in TB+/HIV+/smear+ subjects (21/35; 0.42-0.76). Mycobacterial LAM is detectable in serum with high specificity and reasonable sensitivity using Simoa.

Key Worker-Mediated Enhancement of Physical Health in First Episode Psychosis: Protocol For a Feasibility Study in Primary Care

BACKGROUND

Studies have demonstrated that, for patients with psychosis, a majority of the decline in health status and functioning emerges during the first few years after the onset of illness. This knowledge led to the development of specialized early intervention services (EISs) targeting patients experiencing their first episode of psychosis. The central component of EISs is often assertive case management delivered by a multidisciplinary team, where an appointed key worker is responsible for coordinating treatment and delivering various psychosocial interventions to service users.

OBJECTIVE

This paper outlines the protocol for a feasibility study examining how key workers may enhance physical health by supporting integration between primary and secondary care.

METHODS

Semistructured interviews were conducted with key stakeholder groups (General Practitioners and health care professionals working in mental health services). The interviews informed the development of the complex intervention involving a longitudinal pre-post intervention in 8 general practices in 2 regions in Ireland (one urban and one rural). Patients with first episode psychosis (FEP) will be identified from clinical records at general practices and mental health services.

RESULTS

Baseline and follow-up data (at 6 months) will be collected, examining measures of feasibility, acceptability, and intervention effect size.

CONCLUSIONS

Study findings will inform future practice by examining feasibility of key workers enhancing physical health through improved interaction between primary and secondary care. By identifying issues involved in enhancing recruitment and retention, as well as the likely effect size, the study will inform a future definitive intervention.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/13115.

The role of microglia in processing and spreading of bioactive tau seeds in Alzheimer's disease

Background

Misfolding of microtubule-associated protein tau (MAPT) within neurons into neurofibrillary tangles is an important pathological feature of Alzheimer’s disease (AD). Tau pathology correlates with cognitive decline in AD and follows a stereotypical anatomical course; several recent studies indicate that tau pathology spreads inter-neuronally via misfolded tau “seeds.” Previous research has focused on neurons as the source of these tau seeds. However, recent studies as well as the data contained herein suggest that microglia, the resident immune cells of the central nervous system, play a direct role in the spread of tau pathology.

Methods

Primary adult microglia were isolated from human AD cases and the rTg4510 tauopathy mouse model and used for analysis of gene expression, tau protein by Simoa technology, and quantification of tau seeding using a highly sensitive fluorescence resonance energy transfer (FRET) biosensing cell line for tau seeding and aggregation.

Results

Here, we show that microglia isolated from both human tauopathy and AD cases and the rTg4510 tauopathy mouse model stably contain tau seeds, despite not synthesizing any tau. Microglia releases these tau seeds in vitro into their conditioned media (CM). This suggests that microglia have taken up tau but are incapable of entirely neutralizing its seeding activity. Indeed, when in vitro microglia are given media containing tau seeds, they reduce (but do not eliminate) tau seeding. When microglia are treated with inflammagens such as lipopolysaccharide (LPS), interleukin-1β (IL1β), tumor necrosis factor α (TNFα), or amyloid-β, their ability to reduce tau seeding is unchanged and these factors do not induce seeding activity on their own.

Conclusions

Overall, these data suggest that microglia have a complex role: they are capable of taking up and breaking down seed competent tau, but do so inefficiently and could therefore potentially play a role in the spread of tau pathology.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1309-z) contains supplementary material, which is available to authorized users.

Glial fibrillary acidic protein elevations relate to neuroimaging abnormalities after mild TBI

OBJECTIVES

To determine whether a panel of blood-based biomarkers can discriminate between patients with suspected mild traumatic brain injury (mTBI) with and without neuroimaging findings (CT and MRI).

METHODS

Study participants presented to the emergency department with suspected mTBI (n = 277) with a CT and MRI scan and healthy controls (n = 49). Plasma concentrations of tau, glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal hydrolase L1, and neurofilament light chain (NFL) were measured using the single-molecule array technology.

RESULTS

Concentrations of GFAP, tau, and NFL were higher in patients with mTBI, compared with those of controls (p's < 0.01). GFAP yielded an area under the curve (AUC) of 0.93 (95% confidence interval [CI] 0.90-0.96), confirming its discriminatory power for distinguishing mTBI from controls. Levels of GFAP, tau, and NFL were higher in patients with trauma-related intracranial findings on CT compared with those with normal CT, with the only significant predictor being GFAP (AUC 0.77, 95% CI 0.70-0.84). Among patients with mTBI, tau, NFL, and GFAP differentiated subjects with and without MRI abnormalities with an AUC of 0.83, with GFAP being the strongest predictor. Combining tau, NFL, and GFAP showed a good discriminatory power (AUC 0.80, 95% CI 0.69-0.90) for detecting MRI abnormalities, even in patients with mTBI with a normal CT.

CONCLUSION

Our study confirms GFAP as a promising marker of brain injury in patients with acute mTBI. A combination of various biomarkers linked to different pathophysiologic mechanisms increases diagnostic subgroup accuracy. This multimarker strategy may guide medical decision making, facilitate the use of MRI scanning, and prove valuable in the stratification of patients with brain injuries in future clinical trials.

CLASSIFICATION OF EVIDENCE

Class I evidence that blood concentrations of GFAP, tau, and NFL discriminate patients with mTBI with and without neuroimaging findings.

Comparison of two platforms for the measurement of fg/mL concentrations of protein biomarkers using single molecule arrays and digital ELISA: the benchtop reader Quanterix SR-X™, and the fully automated analyzer HD-1™

Digital ELISA (Enzyme Linked Immunosorbent Assay) based on single molecule arrays (Simoa) has improved sensitivity of traditional ELISA from picomolar (10−12M) to femtomolar (10−15M), increasing the quality and quantity of biomarkers that can be measured for health and disease. Digital ELISA counts signal generated from single immunocomplexes formed on superparamagnetic beads confined in arrays of femtoliter-sized wells in which fluorescent molecules are highly concentrated.

Quanterix has developed digital ELISA assays in a fully-automated instrument (Simoa HD-1 Analyzer), ideal for use in pharmaceutical companies, drug discovery, clinical research and other areas necessitating full automation and high throughput. Recent advancements in the Simoa technology and workflow have been integrated into the new SR-X benchtop reader, with a smaller footprint and more flexible workflow. Operators prepare assays in microtiter plates at the bench in a semi-automated format similar to traditional ELISA, with the notable exception that plates are preserved by drying after assay completion, and can be read immediately or the next day.

We present results comparing performance of the following Simoa assays on SR-X to HD-1: PSA; HIV p24; Tau; Neurofilament-light; PD-L1; TNFa; IL-10; IL-17A; IL-6 and a neurology multiplex panel consisting of NF-L, tau, GFAP and UCH-L1. Measured sample levels correlated with R2 values from 0.96 to 1.00, with average LOD and LLOQ within 1.4 and 1.5 fold of HD-1, respectively. Inter-assay precision ranged from 4.0 to 11.2% CV across assays. Operators tested full-plates from start to finish within 1 – 2 hours (1/2 hour hands on time) and a read time of 2 hours (5 minutes hands on time).

Measuring total IFNα at fg/mL concentrations in human blood

Total IFNα has been challenging to quantify in normal human plasma and serum due to its low abundance and variety of subtypes. Here we describe the development of a digital immunoassay capable of measuring all 12 subtypes of human IFNα in plasma and serum using Quanterix’s Simoa technology. The Simoa digital ELISA technology counts signal generated from single immunocomplexes formed on superparamagnetic beads confined in arrays of femtoliter-sized wells in which fluorescent molecules are highly concentrated. The Simoa IFNα multi-subtype assay has a dynamic range of approximately 3.5 orders of magnitude and a sensitivity below 100 fg/mL. The median LOD (2.5 SD) over 12 runs was approximately 30 fg/mL and the LOQ was approximately 80 fg/mL. This represents a significant improvement over commercial ELISAs, which claim IFNα sensitivities in the pg/mL range. In repeated screens of 30 normal samples, up to 60% measured above LOD and testing of serum from Lupus patients and stimulated PBMCs resulted in concentrations within the dynamic range of the assay. Depletion experiments conducted by incubating unlabeled capture or detection antibody with these same samples demonstrated that the assay is specific for IFNα. IFNα has been useful in several applications including as a therapeutic agent, as a biomarker for monitoring response to immunotherapy, and as a marker of disease progression in human clinical and preclinical studies. In each example, increased sensitivity for detection of all subtypes of IFNα provides researchers and clinicians with the ability to measure the biomarker in both normal and acute samples with robustness required to advance precision medicine programs.

Development of an Ultra-Sensitive Multiplex (6-plex) Cytokine Digital Immunoassay with fg/ml Sensitivity

The future of immuno-oncology treatment and autoimmune diagnostics will involve the detection and quantification of inflammatory biomarkers. As immunotherapy becomes a more common approach for treating cancer and inflammatory disease, cytokines will not only play a role in determining a patient’s disease diagnosis, prognosis, and potential treatment options, but also may serve as a primary index of a therapy’s effectiveness.

Incorporating these biomarkers into clinical practice, however, has been a challenge. Only a few cytokines have been studied in relation to inflammatory disease and immunotherapy, mainly because the biomarkers for these conditions are typically present in very small concentrations, and current research methods aren’t sensitive enough to detect them. It is critical that physicians have the ability to quantify these cytokines to track disease progression before and after treatment.

We present development and characterization of a multiplex digital immunoassay to simultaneously detect and quantify six inflammatory biomarkers (IL-10, IL-12p70, IL-17A, IL-6, TNFa, IFNg) with fg/ml sensitivity. This advanced approach reduces assay volume requirements for multiple sample types and may be sensitive enough to detect circulating disease biomarkers before symptoms appear. As a result, it could potentially provide physicians with a new capability to track disease progression, and the effectiveness of treatments against diseases, which they previously could not monitor with such precision.

A digital enzyme-linked immunosorbent assay for ultrasensitive measurement of amyloid-β 1-42 peptide in human plasma with utility for studies of Alzheimer's disease therapeutics

Background

Amyloid-β 1–42 peptide (Aβ_1–42) is associated with plaque formation in the brain of patients with Alzheimer’s disease (AD). Pharmacodynamic studies of AD therapeutics that lower the concentrations of Aβ_1–42 in peripheral blood require highly sensitive assays for its measurement. A digital enzyme-linked immunosorbent assay (ELISA) using single molecule array (Simoa) technology has been developed that provides improved sensitivity compared with conventional ELISA methods using the same antibody reagents.

Methods

A sensitive digital ELISA for measurement of Aβ_1–42 using antibodies 3D6 and 21F12 was developed. Assay performance was evaluated by repeated testing of pooled human plasma and buffer diluent quality control samples to determine relative accuracy, intra- and inter-assay precision, limit of detection (LOD), lower limit of quantification (LLOQ), dilutional linearity, and spike recovery. The optimized assay was used to quantify Aβ_1–42 in clinical samples from patients treated with the β-site amyloid precursor protein cleaving enzyme 1 inhibitor LY2886721.

Results

The prototype assay measured Aβ_1–42 with an LOD of 0.3 pg/ml and an LLOQ of 2.8 pg/ml in plasma, calibrated using an Aβ_1–42 peptide standard from Fujirebio. Assay precision was acceptable with intra- and inter-assay coefficients of variation both being ≤10%. Dilutional linearity was demonstrated in sample diluent and immunodepleted human plasma. Analyte spike recovery ranged from 51% to 93% with a mean of 80%. This assay was able to quantify Aβ_1–42 in all of the 84 clinical samples tested. A rapid reduction in levels of Aβ_1–42 was detected within 1 h after drug treatment, and a dose-dependent decrease of Aβ_1–42 levels was also observed over the time course of sample collection.

Conclusions

This digital ELISA has potential utility in clinical applications for quantification of Aβ_1–42 in plasma where high sensitivity and precision are required.

Revealing the nature of excitons in liquid exfoliated monolayer tungsten disulphide

Transition metal dichalcogenides (TMD) hold promise for applications in novel optoelectronic devices. There is therefore a need for materials that can be obtained in large quantities and with well understood optical properties. In this report, we present thorough photoluminescence (PL) investigations of monolayer tungsten disulphide obtained via liquid phase exfoliation. As shown by microscopy studies, the exfoliated nanosheets have dimensions of tens of nanometers and thickness of 2.5 monolayers on average. The monolayer content is about 20%. Our studies show that at low temperature the PL is dominated by excitons localized on nanosheet edges. As a consequence, the PL is strongly sensitive to the environment and exhibits an enhanced splitting in magnetic field. As the temperature is increased, the excitons are thermally excited out of the defect states and the dominant transition is that of the negatively charged exciton. Furthermore, upon excitation with a circularly polarized light, the PL retains a degree of polarization reaching 50% and inherited from the valley polarized photoexcited excitons. The studies of PL dynamics reveal that the PL lifetime is on the order of 10 ps, which is probably limited by non-radiative processes. Our results underline the potential of liquid exfoliated TMD monolayers in large scale optoelectronic devices.

Plasma tau in Alzheimer disease

Objective:

To test whether plasma tau is altered in Alzheimer disease (AD) and whether it is related to changes in cognition, CSF biomarkers of AD pathology (including β-amyloid [Aβ] and tau), brain atrophy, and brain metabolism.

Methods:

This was a study of plasma tau in prospectively followed patients with AD (n = 179), patients with mild cognitive impairment (n = 195), and cognitive healthy controls (n = 189) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and cross-sectionally studied patients with AD (n = 61), mild cognitive impairment (n = 212), and subjective cognitive decline (n = 174) and controls (n = 274) from the Biomarkers for Identifying Neurodegenerative Disorders Early and Reliably (BioFINDER) study at Lund University, Sweden. A total of 1284 participants were studied. Associations were tested between plasma tau and diagnosis, CSF biomarkers, MRI measures, ¹⁸fluorodeoxyglucose-PET, and cognition.

Results:

Higher plasma tau was associated with AD dementia, higher CSF tau, and lower CSF Aβ₄₂, but the correlations were weak and differed between ADNI and BioFINDER. Longitudinal analysis in ADNI showed significant associations between plasma tau and worse cognition, more atrophy, and more hypometabolism during follow-up.

Conclusions:

Plasma tau partly reflects AD pathology, but the overlap between normal aging and AD is large, especially in patients without dementia. Despite group-level differences, these results do not support plasma tau as an AD biomarker in individual people. Future studies may test longitudinal plasma tau measurements in AD.

Increases of Plasma Levels of Glial Fibrillary Acidic Protein, Tau, and Amyloid β up to 90 Days after Traumatic Brain Injury

Glial fibrillary acidic protein (GFAP), microtubule-associated protein tau, and amyloid β peptide (Aβ42) have been proposed as diagnostic and prognostic biomarkers in traumatic brain injury (TBI). Single molecule array (Simoa) is a novel technology that employs highly sensitive immunoassays for accurate measurements of candidate biomarkers found at low concentration in biological fluids. Our objective was to trace the trajectory of tau, GFAP, and Aβ42 levels in plasma from the acute through subacute stages after TBI, compared with controls. Samples from 34 TBI subjects enrolled in the Citicoline Brain Injury Treatment Trial (COBRIT) were studied. Injury severity was assessed by Glasgow Coma Scale (GCS) and admission CT. Glasgow Outcome Scale Extended (GOSE) was assessed 6 months after injury. Plasma was collected within 24 h (Day 0), and 30 and 90 days after the TBI. Plasma collected from 69 healthy volunteers was used for comparison. At every time point, increases were noted in plasma GFAP (p < 0.0001 for all comparisons), tau (p < 0.0001, p < 0.0001, and p = 0.0044, at Days 0, 30, and 90, respectively), and Aβ42 (p < 0.001, p < 0.0001, and p = 0.0203, respectively) in TBI cases compared with controls. The levels were maximal at Day 0 for GFAP and tau and at Day 30 for Aβ42. Area under curve (AUC) analyses for Day 0 GFAP and tau were excellent for discrimination of complicated mild TBI (cmTBI) from controls (0.936 and 0.901, correspondingly). Discriminant component analysis (DCA) for all three biomarkers at Days 0 and 30 differentiated controls from cmTBI (91.1% and 89.7% correctly classified, at each time point). Duration of post-traumatic amnesia (PTA) correlated weakly with tau levels at 30 days (Spearman's r = 0.40; 95% CI 0.0003-0.60, p = 0.044). The Marshall CT Grade on admission correlated weakly with Day 30 tau levels (Spearman's r = 0.41; 95% CI 0.04-0.68, p = 0.027). Day 30 Aβ42 correlated with GOSE (standardized β -0.486, p = 0.042). GFAP, tau and Aβ42 were increased up to 90 days after TBI compared with controls. Total tau levels correlated with clinical and radiological variables of TBI severity. Plasma Aβ42 correlated with clinical outcome. Combination of all three biomarkers at Days 0 and 30 can be used to differentiate controls from cmTBI populations, and may be useful as biomarkers of TBI in both acute and subacute phases.

Functions of ectopically transplanted invasive horse trophoblast

The invasive and fully antigenic trophoblast of the chorionic girdle portion of the equine fetal membranes has the capacity to survive and differentiate after transplantation to ectopic sites. The objectives of this study were to determine i) the survival time of ectopically transplanted allogeneic trophoblast cells in non-pregnant recipient mares, ii) whether equine chorionic gonadotropin (eCG) can be delivered systemically by transplanted chorionic girdle cells, and iii) whether eCG delivered by the transplanted cells is biologically active and can suppress behavioral signs associated with estrus. Ectopically transplanted chorionic girdle survived for up to 105 days with a mean lifespan of 75 days (95% confidence interval 55-94) and secreted sufficient eCG for the hormone to be measurable in the recipients' circulation. Immunohistochemical labeling of serial biopsies of the transplant sites and measurement of eCG profiles demonstrated that graft survival was similar to the lifespan of equine endometrial cups in normal horse pregnancy. The eCG secreted by the transplanted cells induced corpora lutea formation and sustained systemic progesterone levels in the recipient mares, effects that are also observed during pregnancy. This in turn caused suppression of estrus behavior in the recipients for up to 3 months. Thus, ectopically transplanted equine trophoblast provides an unusual example of sustained viability and function of an immunogenic transplant in a recipient with an intact immune system. This model highlights the importance of innate immunoregulatory capabilities of invasive trophoblast cells and describes a new method to deliver sustained circulating concentrations of eCG in non-pregnant mares.

Dihydrostreptomycin or streptomycin in combination with penicillin G in dairy cattle therapeutics: A review and re-analysis of published data Part 2: Resistance and residues

Combination formulations of penicillin G salts and dihydrostreptomycin were developed during the 1960s and are currently marketed in New Zealand for parenteral and intramammary use in dairy cattle. In this paper, the second part of a two paper series, the mechanisms by which bacteria develop resistance to each of these drugs independently is reviewed and the impact of this resistance on potential for synergy is discussed. Further, the considerable potential for tissue drug residues with dihydrostreptomycin or streptomycin from these formulations is examined by re-analysis of literature data, demonstrating an urgent need to reassess the place for aminoglycoside-containing formulations in dairy cattle therapeutics.

Pertussis knowledge, attitude and practices among European health care professionals in charge of adult vaccination

Despite successful infant vaccination programmes, pertussis remains endemic in many countries. Waning immunity leaves adolescents and adults susceptible to disease and potential reservoirs of infection allowing transmission to vulnerable infants. Misdiagnosis leads to significant underestimation of disease burden and inappropriate treatment. This online survey of 517 European health care professionals (HCP) examined their knowledge, attitudes and practices regarding pertussis and adult vaccination. Compared with other vaccine-preventable diseases, HCPs did not perceive pertussis as a serious disease in adults and there was a low perceived need for adult vaccination; only 17% mentioned pertussis as a disease they would usually vaccinate adults against. Pertussis incidence was considered to be low. Although the majority of HCPs agreed that vaccination is useful to prevent pertussis transmission from adults to susceptible infants, respondents discussed pertussis vaccination with ≤5% of patients; 58% respondents had never prescribed a pertussis vaccine to adults. The perceived low incidence of pertussis in adults and the lack of official guidelines/ recommendations were cited as key reasons for not administering pertussis boosters. Despite only taking place in four countries, our results suggest that the incidence and burden of adult pertussis is not reflected in the attitudes of European HCPs to the disease. Awareness of adult pertussis, its diagnosis and guidance on pertussis boosters should be raised to protect adults and vulnerable infants and to manage the consequences of waning pertussis immunity.

The clonotypic T cell receptor is a source of tumor-associated antigens in cutaneous T cell lymphoma

To develop cancer vaccines for the treatment of cutaneous T cell lymphoma (CTCL), immunogenic peptides were identified by two approaches. First, through the use of "reverse immunology" the peptide sequence of the idiotypic region of the beta chain of the T cell receptor (TCR) was determined and a series of overlapping peptides synthesized and tested for CD8 T cell recognition. In two patients, the idiotypic CDR3 region provided immunogenic epitopes that were recognized in a class I-restricted fashion by autologous CD8 T cell lines. In a second strategy, peptides were isolated directly from class I MHC molecules on the CTCL surface and sequenced. A peptide with partial homology to sequences contained in the conserved variable portion of the clonotypic TCR beta chain was recognized as immunogenic by autologous CD8 T cells. Therefore, both approaches demonstrated that the clonotypic TCR in CTCL is a source of immunogenic tumor epitopes. To confirm that recognition of TCR-derived sequences provides immunoprotection against tumor growth, a murine model of T cell lymphoma was studied. The immunogenicity of a thymoma, which lacks cell surface TCR expression, was enhanced by transfection of the beta chain of the TCR. The studies reviewed in this paper demonstrate that the TCR can serve as one source for immunogenic tumor peptides in T cell lymphoma in vitro and in vivo. Presentation of TCR epitopes on dendritic cells that express high levels of MHC, costimulatory, and adhesion molecules may provide an effective means for immunization against T cell malignancy.

Induction of human tumor-loaded dendritic cells

A preferred anti-cancer vaccine would be tumor-specific, simple to rapidly construct and safe to administer. It would permit immunization against a spectrum of the tumor's distinctive antigens, without requiring their prior identification. Toward these goals, we describe a modification of standard extracorporeal photopheresis (ECP) which initiates, within a single day, both monocyte-to-dendritic cell (DC) differentiation and malignant cell apoptosis. The transition of monocytes to immature DCs was identified by the expression of cytoplasmic CD83 and membrane CD36 in the absence of membrane CD14 staining, as well as induction of membrane CD83 expression. Differentiating DCs were avidly phagocytic and engulfed apoptotic malignant T cells. Differentiating DCs were capable of stimulating significant proliferation of normal alloreactive lymphocyte responders, indicting increased expression of membrane MHC class II molecules. This approach provides a clinically practical means of developing tumor-loaded cells that have initiated the transition to DCs without the requirement of exogenous cytokines, excessive cellular manipulation or isolation. Construction of DC vaccines using this methodology can be generalized to other diseases and may offer a novel approach for improved cancer immunotherapy.

An integrated software suite for surface-based analyses of cerebral cortex

The authors describe and illustrate an integrated trio of software programs for carrying out surface-based analyses of cerebral cortex. The first component of this trio, SureFit (Surface Reconstruction by Filtering and Intensity Transformations), is used primarily for cortical segmentation, volume visualization, surface generation, and the mapping of functional neuroimaging data onto surfaces. The second component, Caret (Computerized Anatomical Reconstruction and Editing Tool Kit), provides a wide range of surface visualization and analysis options as well as capabilities for surface flattening, surface-based deformation, and other surface manipulations. The third component, SuMS (Surface Management System), is a database and associated user interface for surface-related data. It provides for efficient insertion, searching, and extraction of surface and volume data from the database.

A lymphocyte cell surface heat shock protein homologous to the endoplasmic reticulum chaperone, immunoglobulin heavy chain binding protein BIP

BE2 is a cell surface monomeric 78-kDa protein (BE2-78) expressed on the malignant lymphocytes of cutaneous T-cell lymphoma and adult T-cell leukemia, on some lymphocytes from patients with acquired immunodeficiency syndrome and on Epstein-Barr virus-transformed B cells. BE2-78 positivity of cutaneous T-cell lymphoma tumor cells is a useful diagnostic and prognostic determinant in evaluating patients with that disorder. The BE2-78 protein was isolated from Epstein Barr virus-transformed B cells, purified by 1- and 2-dimensional electrophoresis and then sequenced. The sequence of 4 isolated peptide fragments was highly homologous with the 78-kDa heat shock protein, BiP, an endoplasmic reticulum chaperone. The similarity between BiP and BE2-78 was supported by the demonstration that BE2-78, like BiP, avidly binds to ATP. However, polyclonal and monoclonal reagents that recognize cytoplasmic 70- and 78-kDa heat shock proteins do not detect the BE2-78 antigen on the cell surface of cutaneous T-cell lymphoma or Epstein Barr virus-transformed lymphocytes, and peptide mapping demonstrates sequence divergence, suggesting that either they are distinct or conformationally different molecules. Our results indicate that BE2-78 is a cell surface heat shock protein. The possibility that malignant or transformed lymphocytes may express cell surface molecules with the capacity to bind a spectrum of exogenous or endogenous peptides has potential implications for tumor immunology.

Aberrant retention of tyrosinase in the endoplasmic reticulum mediates accelerated degradation of the enzyme and contributes to the dedifferentiated phenotype of amelanotic melanoma cells

The loss of tyrosinase, the key enzyme in melanin synthesis, has been implicated in the dedifferentiation of malignant melanocytes. The presence of tyrosinase transcripts and antigenic peptides in melanoma tumors prompted us to investigate whether the basis for the loss of the enzyme was proteolytic degradation. Toward this aim, we followed the kinetics of synthesis, degradation, processing, chaperone binding, inhibitor sensitivity, and subcellular localization of tyrosinase in normal and malignant melanocytes. We found that, in amelanotic melanoma cell lines, tyrosinase failed to reach the melanosome, the organelle for melanin synthesis, because it was retained in the endoplasmic reticulum (ER) and then degraded. Tyrosinase appeared mostly as a 70-kDa core-glycosylated, endoglycosidase H-sensitive, immature form bound to the ER chaperone calnexin and had a life-span of only 25% of normal. Maturation and transit from the ER to the Golgi compartment was facilitated by lowering the temperature of incubation to 31 degrees C. Several proteasome inhibitors caused the accumulation of an approximately 60-kDa tyrosinase doublet that was more prominent in malignant than in normal melanocytes and promoted, to various degrees, the maturation of tyrosinase in melanoma cells and the translocation of the enzyme to melanosomes. The appearance of ubiquitinated tyrosinase after treatment of normal melanocytes with N-acetyl-L-leucinyl-L-leucinal-L-norleucinal reinforced our notion that some tyrosinase is normally degraded by proteasomes. Proteolysis of tyrosinase by proteasomes is consistent with the production of antigenic tyrosinase peptides that are presented to the immune system by major histocompatibility complex class I molecules.

Dihydrostreptomycin or streptomycin in combination with penicillin G in dairy cattle therapeutics: A review and re-analysis of published data Part 1: Clinical pharmacology

Combination formulations of penicillin G salts and dihydrostreptomycin were developed during the 1960s and are currently marketed in New Zealand for parenteral and intramammary use in dairy cattle. In this paper, the clinical indications and efficacy, pharmacokinetics and potential for antimicrobial synergy of penicillin and dihydrostreptomycin or streptomycin, when combined, are discussed.

The effects on the pharmacokinetics of intravenous ceftiofur sodium in dairy cattle of simultaneous intravenous acetyl salicylate (aspirin) or probenecid

Ceftiofur sodium is a third-generation cephalosporin antibiotic. It is possible that non-steroidal anti-inflammatory drugs such as acetyl salicylate (aspirin) may be used concomitantly with ceftiofur sodium in dairy cattle. Therefore this study evaluated potential pharmacokinetic interactions between ceftiofur sodium and aspirin. In addition, this study evaluated the potential for interaction between ceftiofur and its active metabolites and the organic anion transporter. The organic anion transporter substrate used in this evaluation was probenecid. Ten healthy, non-pregnant, non-lactating dairy cows were used in a randomized complete three-way crossover design. In repeated experiments all cows were administered: (1) 2 mg of ceftiofur sodium per kg body weight by intravenous bolus or (2) 10 mg of probenecid per kg body weight by intravenous bolus, followed immediately by 2 mg of ceftiofur sodium per kg body weight by intravenous bolus or (3) 26 mg of aspirin per kg body weight by intravenous bolus, followed immediately by 2 mg of ceftiofur sodium per kg body weight by intravenous bolus. For treatment with ceftiofur sodium alone, the mean volume of distribution at steady-state Vd(ss) was 0.2 +/- 0.06 L/kg, the mean volume of distribution by the area method Vd(area) was 0.38 +/- 0.22 L/kg, mean residence time (MRT) was 6.5 +/- 1.8 h, mean residence time in peripheral tissues (MRTp) was 2.6 +/- 1.0 h, total body clearance (Cl) was 0.032 +/- 0.013 L/kg/h and elimination rate constant (beta) was 0.097 +/- 0.044 h-1 (mean +/- standard deviation). No statistically significant changes were detected as a result of preceding treatment with aspirin.(ABSTRACT TRUNCATED AT 250 WORDS)

Unrecognized pathologic fractures of the cervical spine: two case reports and review of the literature

Two cases of undiagnosed pathologic fractures of the cervical spine are presented. A discussion of the pathogenesis, typical presentation, and the optimal emergency department evaluation of a possible pathologic fracture of the cervical spine follows the reports.

Dissections of the cervicocerebral arteries

We present four cases of cerebral ischemia secondary to dissections of cervicocerebal arteries. The majority of patients presented with transient ischemic attacks and strokes, although one patient presented with headache and focal seizure. In addition to history and physical examination, the diagnostic evaluation of these patients included computed tomography scan, carotid duplex studies, angiogram, and, in some cases, magnetic resonance imaging studies. Initially, the patients were anticoagulated with heparin and then with warfarin for a period of six to eight weeks. The emergency physician must consider such dissections in younger patients with sudden neurologic deficits and no or few risk factors for cerebrovascular disease. In our experience, these are not rare syndromes; with proper workup, prompt diagnosis, and therapy, the prognosis is usually excellent.