The Correlation of Endogenous Progesterone Concentration in Diestrus on Early Pregnancy Rate in Thoroughbred Mares.

The aim of this project was to test the hypothesis that progesterone concentration 5 days after ovulation did not differ between pregnant and nonpregnant Thoroughbred mares on stud farms located in the Waikato region of New Zealand. A prospective cohort study was performed involving five stud farms in the Waikato region of New Zealand during the 2018 breeding season. A total of 275 mares were enrolled in the study. Mares were served by 34 individual stallions. Blood samples were taken from each mare 5 days after ovulation (D0) and measured for progesterone concentration. Early pregnancy was confirmed at D14 by transrectal palpation and ultrasonography of the mares reproductive tract. Progesterone concentration at Day 5 post-ovulation was higher in mares determined to pregnant at Day 14 of gestation than in mares determined to be non-pregnant at Day 14 (6.4 ± 3.0 ng/ml vs. 5.5 ± 3.3 ng/ml respectively; P = .02). A negative association between increasing mare age and pregnancy rate was found but mare age had no effect on progesterone concentration at D5. In this study we found that although higher serum progesterone concentration at Day 5 post ovulation was associated with a higher pregnancy rate at Day 14, no predictive or definitive minimum required progesterone concentration could be identified. Additional studies are required to determine if a synthetic progestogens can serve to supplant natural progesterone to increase pregnancy rate in naturally bred mares.

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.

Disparities in Oral Nutritional Supplement Usage and Dispensing Patterns across Primary Care in Ireland: ONSPres Project.

When treating malnutrition, oral nutritional supplements (ONSs) are advised when optimising the diet is insufficient; however, ONS usage and user characteristics have not been previously analysed. A retrospective secondary analysis was performed on dispensed pharmacy claim data for 14,282 anonymised adult patients in primary care in Ireland in 2018. Patient sex, age, residential status, ONS volume (units) and ONS cost (EUR) were analysed. The categories of 'Moderate' (<75th centile), 'High' (75th-89th centile) and 'Very High' ONS users (≥90th centile) were created. The analyses among groups utilised t-tests, Mann-Whitney U tests and chi-squared tests. This cohort was 58.2% female, median age was 76 years, with 18.7% in residential care. The most frequently dispensed ONS type was very-high-energy sip feeds (45% of cohort). Younger males were dispensed more ONSs than females (<65 years: median units, 136 vs. 90; p < 0.01). Patients living independently were dispensed half the volume of those in residential care (112 vs. 240 units; p < 0.01). 'Moderate' ONS users were dispensed a yearly median of 84 ONS units (median cost, EUR 153), 'High' users were dispensed 420 units (EUR 806) and 'Very High' users 892 yearly units (EUR 2402; p < 0.01). Further analyses should focus on elucidating the reasons for high ONS usage in residential care patients and younger males.

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.

Blood Biomarkers of Sports-Related Concussion in Pediatric Athletes.

OBJECTIVE: To examine changes in blood biomarkers, serum neurofilament light (Nf-L), and plasma tau, as well as the relationship between blood biomarkers and symptom reports, in athletes with a sports-related concussion. DESIGN: Prospective cohort study. SETTING: Private community-based concussion clinic. PARTICIPANTS: Athletes aged 13 to 18 years old with a diagnosed sports-related concussion presenting to a concussion clinic within 7 days of injury and noninjured athletes with no history of concussion aged 13 to 23 years old. ASSESSMENT AND MAIN OUTCOME MEASURES: Injured athletes provided a blood sample at the initial clinical evaluation and again at least 6 months after injury. Noninjured athletes provided a single blood sample. All participants completed symptom reports during each visit. Statistical comparisons of biomarker concentrations and symptom reports were conducted. RESULTS: The mean rank for tau was significantly lower for concussed athletes compared with nonconcussed athletes. In contrast, the mean rank of Nf-L was higher for concussed athletes than for nonconcussed athletes, although the difference was nonsignificant. Plasma tau was significantly lower postinjury compared with 6 months after injury, whereas serum Nf-L was significantly higher postinjury. There was a weak but significant inverse relationship observed between tau and the number of symptoms reported, but no relationship was observed between Nf-L and the number of symptoms reported. CONCLUSIONS: These data indicate that in the days following a sports-related concussion, the blood biomarkers tau and Nf-L display contrasting patterns of change but may not be related to self-reported symptom scores.

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.

General practitioners' views on malnutrition management and oral nutritional supplementation prescription in the community: A qualitative study.

BACKGROUND & AIMS: Malnutrition or undernutrition, arising from a deficiency of energy and protein intake, occurs commonly among community-dwelling individuals in developed countries. Once identified, malnutrition can be effectively treated in the majority of cases with dietary advice and the prescription of oral nutritional supplements (ONS) for patients who can eat and drink orally. However, previous research has reported inadequate screening and treatment of malnutrition in the community. The aim of this qualitative study was to explore general practitioners' (GPs) experiences and opinions on the management of malnutrition and the prescription of ONS in the primary care/community setting in Ireland. METHODS: Sixteen semi-structured interviews including chart stimulated recalls (CSR) were conducted with GPs. The interviews and CSRs explored, among others, the following domains; barriers and facilitators in the management of malnutrition, ONS prescribing in the primary care/community setting, and future directions in the management of malnutrition and ONS prescribing. Recorded interviews were transcribed and analysed following a generic qualitative approach with inductive thematic analysis using NVIVO 12 to facilitate data management. RESULTS: Three main themes were identified. Theme 1: 'Malnutrition is a secondary concern', encapsulating the idea that the identification of malnutrition is usually secondary to other clinical issues or disease rather than an independent clinical outcome. This theme also includes the idea that obesity is viewed as a dominant nutritional issue for GPs. Theme 2: 'Responsibility for malnutrition and ONS management in the community', highlighting that GPs feel they do not know who is responsible for the management of malnutrition in the community setting and expressed their need for more support from other healthcare professionals (HCPs) to effectively monitor and treat malnutrition. Theme 3: 'Reluctance to prescribe ONS', emerging from the GPs reported lack of knowledge to prescribe the appropriate ONS, their concern that ONS will replace the patient's meals and the costs associated with the prescription of ONS. CONCLUSIONS: GPs in Ireland do not routinely screen for malnutrition in their clinics as they feel unsupported in treating and managing malnutrition in the community due to limited or no dietetic service availability and time constraints. GPs also view malnutrition as a secondary concern to disease management and prioritise referral to dietetic services for patients with overweight and obesity. GPs reported that they have insufficient knowledge to change or discontinue ONS prescriptions. This study demonstrates that there is a clear need for primary care training in malnutrition identification, treatment and management and more community dietetic services are needed in order to support GPs and deliver high quality care to patients.

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-1ß (IL1ß), tumor necrosis factor α (TNFα), or amyloid-ß, 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.

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.

Treatment of Retained Fetal Membranes in the Mare-A Practitioner Survey.

Retained fetal membranes (RFM) is a common post-partum problem in mares for which the treatment is highly variable. The aim of this study was (i) to investigate the different treatments used by equine practitioners for RFM and (ii) to determine if there is a difference between treatments used by reproductive specialists and general equine practitioners. Information regarding treatment of RFM was sought from veterinary practitioners via a survey and this was compared to recommendations in the current literature. The survey was sent out to equine veterinarians and mixed practitioners with a high equine case load. Most treatments of RFM were in line with current recommendations, while some obsolete practices are still routinely performed by a small number of practitioners. Treatment recommendations for RFM have changed over the last few decades, but there are no universally accepted guidelines. The vast variety of treatments reported by practitioners in the present survey reflect this lack of guidance. More extensive research is needed in this area to establish evidence-based, uniformly agreed upon protocols.

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

Glial fibrillary acidic protein (GFAP), microtubule-associated protein tau, and amyloid ß peptide (Aß42) 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 Aß42 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 Aß42 (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 Aß42. 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 Aß42 correlated with GOSE (standardized ß -0.486, p = 0.042). GFAP, tau and Aß42 were increased up to 90 days after TBI compared with controls. Total tau levels correlated with clinical and radiological variables of TBI severity. Plasma Aß42 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.

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

BACKGROUND: Amyloid-ß 1-42 peptide (Aß1-42) 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 Aß1-42 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 Aß1-42 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 Aß1-42 in clinical samples from patients treated with the ß-site amyloid precursor protein cleaving enzyme 1 inhibitor LY2886721. RESULTS: The prototype assay measured Aß1-42 with an LOD of 0.3 pg/ml and an LLOQ of 2.8 pg/ml in plasma, calibrated using an Aß1-42 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 Aß1-42 in all of the 84 clinical samples tested. A rapid reduction in levels of Aß1-42 was detected within 1 h after drug treatment, and a dose-dependent decrease of Aß1-42 levels was also observed over the time course of sample collection. CONCLUSIONS: This digital ELISA has potential utility in clinical applications for quantification of Aß1-42 in plasma where high sensitivity and precision are required.

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 ß-amyloid [Aß] 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 Aß42, 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.

An analytic observational study on complaints management in the general practice out of hours care setting: who complains, why, and what can we do about it?

BACKGROUND: General Practice Co-Operatives provide most out of hours care in communities in Ireland. Limited data exists on patient complaints. This study reports on complaints at Kildare and West Wicklow Doctors on Call ('K Doc'), a GP Co-Operative in Ireland, examining the impact of a formal risk reduction strategy implemented (2010-2013). The aim of the study was to determine if it was possible to reduce the rate of written complaints per 1000 consultations through a formal approach encompassing evaluation of complaints, improved communication in relation to complaints, and more direct use of insights gained from complaints analysis in continuing professional development at the Co-Operative. METHODS: Initially, complaints submitted over an 18 month period (01.06.08 to 31.12.09) were analysed. Complaint rate (number of complaints per 1000 consultations), complainant demographics, aspects of complaint response at the Co-Operative, and nature of complaint were recorded. Based on analysis, a risk reduction strategy was undertaken, including procedural change, focused training and education. Areas selected for improvement during a second phase of data collection included complaints rate, timeliness of Co-Operative response to complaint, and rate of complaint notification to patient's GP. Further analysis was then carried out over a 45 month period (01.01.10 to 30.09.13). RESULTS: From 2008-2013, 216,716 patient consultations occurred. Complaints were received from 131 individuals, regarding 125 patients. Following introduction of risk reduction strategy, complaints rate reduced by 36 %, from 0.77 to 0.49 per 1000 consultations (p = 0.02) between the two periods of data collection. Timeliness of response from Co-Operative to the complainant improved from 63 % to 75 %. Notification of complaint to the patient's GP improved from 48 % to 96 %. Most complaints were not associated with medically significant events. The largest categories of complaint related to clinical care (55 % n = 69), cost (46 %, n = 58), communication (42 %, n = 53), and process of care (15 %, n = 19). Mothers of affluent paediatric patients were most likely to make formal complaints. CONCLUSIONS: This study reports a statistically significant reduction in complaints rate of 36 % following introduction of risk reduction strategies at a GP Co -Operative. Out of hours consulting is known to be an area of high medical risk. Findings are of interest where number and costs of complaints against GPs are elsewhere reported to be rising, contributing to medical inflation, and to public concern.

Plasma ß-amyloid in Alzheimer's disease and vascular disease.

Implementation of amyloid biomarkers in clinical practice would be accelerated if such biomarkers could be measured in blood. We analyzed plasma levels of Aß42 and Aß40 in a cohort of 719 individuals (the Swedish BioFINDER study), including patients with subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer's disease (AD) dementia and cognitively healthy elderly, using a ultrasensitive immunoassay (Simoa platform). There were weak positive correlations between plasma and cerebrospinal fluid (CSF) levels for both Aß42 and Aß40, and negative correlations between plasma Aß42 and neocortical amyloid deposition (measured with PET). Plasma levels of Aß42 and Aß40 were reduced in AD dementia compared with all other diagnostic groups. However, during the preclinical or prodromal AD stages (i.e. in amyloid positive controls, SCD and MCI) plasma concentration of Aß42 was just moderately decreased whereas Aß40 levels were unchanged. Higher plasma (but not CSF) levels of Aß were associated with white matter lesions, cerebral microbleeds, hypertension, diabetes and ischemic heart disease. In summary, plasma Aß is overtly decreased during the dementia stage of AD indicating that prominent changes in Aß metabolism occur later in the periphery compared to the brain. Further, increased levels of Aß in plasma are associated with vascular disease.

CSF and plasma amyloid-ß temporal profiles and relationships with neurological status and mortality after severe traumatic brain injury.

The role of amyloid-ß (Aß) neuropathology and its significant changes in biofluids after traumatic brain injury (TBI) is still debated. We used ultrasensitive digital ELISA approach to assess amyloid-ß1-42 (Aß42) concentrations and time-course in cerebrospinal fluid (CSF) and in plasma of patients with severe TBI and investigated their relationship to injury characteristics, neurological status and clinical outcome. We found decreased CSF Aß42 levels in TBI patients acutely after injury with lower levels in patients who died 6 months post-injury than in survivors. Conversely, plasma Aß42 levels were significantly increased in TBI with lower levels in patients who survived. A trend analysis showed that both CSF and plasma Aß42 levels strongly correlated with mortality. A positive correlation between changes in CSF Aß42 concentrations and neurological status as assessed by Glasgow Coma Scale (GCS) was identified. Our results suggest that determination of Aß42 may be valuable to obtain prognostic information in patients with severe TBI as well as in monitoring the response of the brain to injury.

Simple diffusion-constrained immunoassay for p24 protein with the sensitivity of nucleic acid amplification for detecting acute HIV infection.

Nucleic acid amplification techniques have become the mainstay for ultimate sensitivity for detecting low levels of virus, including human immunodeficiency virus (HIV). As a sophisticated technology with relative expensive reagents and instrumentation, adoption of nucleic acid testing (NAT) can be cost inhibited in settings in which access to extreme sensitivity could be clinically advantageous for detection of acute infection. A simple low cost digital immunoassay was developed for the p24 capsid protein of HIV based on trapping enzyme-labeled immunocomplexes in high-density arrays of femtoliter microwells and constraining the diffusion of the enzyme-substrate reaction. The digital immunoassay was evaluated for analytical sensitivity for HIV capsid protein p24, and compared with commercially available NAT methods and immunoassays for p24, including 4th-generation antibody/antigen combo assays, for early detection of HIV in infected individuals. The digital immunoassay was found to exhibit 2000-3000-fold greater analytical sensitivity than conventional immunoassays reactive for p24, and comparable sensitivity to NAT methods. Assaying serial samples from 10 HIV-infected individuals, the digital immunoassay detected acute HIV infection as early as NAT methods, and 7-10 days earlier than conventional immunoassays. Comparison of assay results between the digital immunoassay and a quantitative NAT method from HIV infected serum exhibited a linear correlation R(2)>0.99. The data indicate that by constraining diffusion of the signal generation step of a simple sandwich immunoassay and enabling the digital counting of immunocomplexes, dramatic improvements in sensitivity to virus can be obtained to match the sensitivity of NAT at a fraction of the cost.