Intraventricular murine Aß infusion elicits hippocampal inflammation and disrupts the consolidation, but not retrieval, of conditioned fear in C57BL6/J mice.

Although one of the defining characteristics of Alzheimer's disease is the presence of amyloid-beta (Aß) plaques, the early accumulation of soluble Aß oligomers (AßOs) may disrupt synaptic function and trigger cognitive impairments long before the appearance of plaques. Furthermore, murine models aimed at understanding how AßOs alter formation and retrieval of associative memories are conducted using human Aß species, which are more neurotoxic in the mouse brain than the native murine species. Unfortunately, there is currently a lack of attention in the literature as to what the murine version of the peptide (mAß) does to synaptic function and how it impacts the consolidation and retrieval of associative memories. In the current study, adult mice were infused with mAß 0, 2, 6, or 46 h after contextual-fear conditioning, and were tested 2-48 h later. Interestingly, only mAß infusions within 2 h of training reduced freezing behavior at test, indicating that mAß disrupted the consolidation, but not retrieval of fear memory. This consolidation deficit coincided with increased IL-1ß and reduced synaptophysin mRNA levels, without disrupting other synaptic signaling-related genes here examined. Despite differences between murine and human Aß, the deleterious functional outcomes of early-stage synaptic oligomer presence are similar. Thus, models utilizing or inducing the production of mAß in non-transgenic animals are useful in exploring the role of dysregulated synaptic plasticity and resultant learning deficits induced by Aß oligomers.

Prolonged isolation stress accelerates the onset of Alzheimer's disease-related pathology in 5xFAD mice despite running wheels and environmental enrichment.

Research has demonstrated that stress can exacerbate AD pathology in transgenic mouse models of AD. The purpose of the present studies was to extend this work by determining whether a social stressor, isolation stress, would increase the number of Aß plaques in 5xFAD + transgenic mice in comparison to group-housed controls, and accelerate the onset of cognitive deficits in contextual fear-conditioning. Additionally, we aimed to determine whether the pathological impact of isolation stress could be prevented through exposure to exercise alone or to exercise and an enriched environment throughout the isolation period. Two-month-old 5xFAD + and 5xFAD- animals were isolated or group-housed for two and three months. An additional subset of 5xFAD + mice were housed in isolation, housed in isolation with an exercise wheel, or housed in isolation with an exercise wheel and an enriched environment. Both two and three months of isolation stress significantly increased the number of plaques in the hippocampus of 5xFAD + mice, and three months of isolation increased hippocampal BACE1 expression. Isolated animals also displayed a significant cognitive deficit in contextual fear-conditioning, independent of genotype. Furthermore, neither exercise nor an enriched environment were able to prevent these isolation-induced effects. Understanding how stress impacts the onset and progression of AD is critical, as many individuals endure significant stress over their lifespan, including prolonged social isolation, a societal trend likely to worsen with time.

The α5-GABAAR inverse agonist MRK-016 upregulates hippocampal BDNF expression and prevents cognitive deficits in LPS-treated mice, despite elevations in hippocampal Aß.

Alzheimer's disease is marked by the presence of amyloid-beta (Aß) plaques, elevated central cytokine levels, dysregulation of BDNF-related gene expression, and cognitive decline. Previously, our laboratory has demonstrated that repeated administration of peripheral LPS is sufficient to significantly increase the presence of central Aß in the hippocampus, and that this upregulation corresponds with deficits in learning and memory. We have also previously demonstrated that the inverse benzodiazepine agonist MRK-016 (MRK) can protect against memory acquisition and consolidation errors in mice. To extend these findings, the current study explored the protective effects of MRK in the context of LPS-induced hippocampal Aß accumulation. Hippocampal Aß was significantly elevated, relative to saline-treated animals, following seven days of peripheral LPS injections. Animals were then trained in a contextual fear conditioning paradigm and were immediately treated with MRK or saline once training was complete. Behavioral testing occurred the day after training. Results from this study demonstrate that repeated injections of LPS significantly elevate hippocampal Aß, and inhibit acquisition of contextual fear. Post-training treatment with MRK restored behavioral expression of fear in LPS-treated animals, despite elevated hippocampal Aß, an effect that may be attributed to increased BDNF mRNA expression. Therefore, our data indicate that MRK can prevent LPS- induced cognitive deficits associated with elevated Aß, and restore hippocampal BDNF expression.

Healthful, Cultural Foods and Safety Net Use Among Cambodian and Brazilian Immigrant Communities in Massachusetts.

Declining health and food security status among low-income immigrants in the U.S. may result from limited access to healthful, cultural foods and safety net programs. We held focus group discussions with low-income Cambodian and Brazilian immigrants (11 groups, n = 84) living in Massachusetts. Cambodians and Brazilians valued healthful, cultural foods, emphasizing their beliefs that cultural foods are healthier and beneficial for weight management and aging. Although both groups could access these foods, some individuals had difficulty affording them. Cambodians reported that food quality decreased over the month due to inadequate resources. Cambodians relied on SNAP, WIC, families, and food pantries; however, Brazilians generally did not participate in safety net programs. Barriers to accessing and using safety nets appear to limit diet quality for some immigrant families. Targeted nutrition interventions should build on current knowledge of and desire for healthful, cultural foods in the context of available safety nets.

Design of a Virtual Reality System for Affect Analysis in Facial Expressions (VR-SAAFE); Application to Schizophrenia.

Schizophrenia is a life-long, debilitating psychotic disorder with poor outcome that affects about 1% of the population. Although pharmacotherapy can alleviate some of the acute psychotic symptoms, residual social impairments present a significant barrier that prevents successful rehabilitation. With limited resources and access to social skills training opportunities, innovative technology has emerged as a potentially powerful tool for intervention. In this paper, we present a novel virtual reality (VR)-based system for understanding facial emotion processing impairments that may lead to poor social outcome in schizophrenia. We henceforth call it a VR System for Affect Analysis in Facial Expressions (VR-SAAFE). This system integrates a VR-based task presentation platform that can minutely control facial expressions of an avatar with or without accompanying verbal interaction, with an eye-tracker to quantitatively measure a participants real-time gaze and a set of physiological sensors to infer his/her affective states to allow in-depth understanding of the emotion recognition mechanism of patients with schizophrenia based on quantitative metrics. A usability study with 12 patients with schizophrenia and 12 healthy controls was conducted to examine processing of the emotional faces. Preliminary results indicated that there were significant differences in the way patients with schizophrenia processed and responded towards the emotional faces presented in the VR environment compared with healthy control participants. The preliminary results underscore the utility of such a VR-based system that enables precise and quantitative assessment of social skill deficits in patients with schizophrenia.

Estimating Energy Expenditure using Individualized, Power-Specific Gross Efficiencies.

Our purpose was to determine if using an individual's power-specific gross efficiency improves the accuracy of estimating energy expenditure from cycling power. 30 subjects performed a graded cycling test to develop 4 gross efficiencies: individual power-specific gross efficiencies, a group mean power-specific gross efficiency, individual fixed gross efficiencies, and a group mean fixed gross efficiency. Energy expenditure was estimated from power using these different gross efficiencies and compared to measured energy expenditure during moderate- and hard-intensity constant-power and 2 variable-power cycling bouts. Estimated energy expenditures using individual or group mean power-specific gross efficiencies were not different from measured energy expenditure across all cycling bouts (p>0.05). To examine the intra-individual variability of the estimates, absolute difference scores (absolute value of estimated minus measured energy expenditure) were compared, where values closer to zero represent more accurate individual estimates. The absolute difference score using individual power-specific gross efficiencies was significantly lower compared to the other gross efficiencies across all cycling bouts (p<0.01). Significant and strong correlations (r≥0.97, p<0.001) were found across all cycling bouts between estimated and measured energy expenditures using individual power-specific gross efficiencies. In conclusion, using an individual's power-specific gross efficiency significantly improves their energy expenditure estimate across different power outputs.

Hippocampal Aß expression, but not phosphorylated tau, predicts cognitive deficits following repeated peripheral poly I:C administration.

Alzheimer's disease is marked by the accumulation of the amyloid-beta (Aß) peptide, and increases in phosphorylation of the microtubule associated protein, tau. Changes in these proteins are considered responsible, in part, for the progressive neuronal degeneration and cognitive deficits seen in AD. We examined the effect of repeated consecutive peripheral poly I:C injections on cognitive deficits, central Aß, and phosphorylated tau accumulation, following three treatment durations: 7, 14, and 21 days. Forty-eight hours after the final injection, animals were trained in a contextual fear-conditioning paradigm, and tested 24h later. Immediately after testing, the hippocampus was collected to quantify Aß and phosphorylated tau accumulation. Results showed that, although poly I:C-induced Aß was significantly elevated at all time points examined, poly I:C only disrupted cognition after 14 and 21 days of administration. Moreover, elevations in phosphorylated tau were not seen until the 14-day time point. Interestingly, phosphorylated tau expression then declined at the 21-day time point. Finally, we demonstrated that Aß levels are a stronger predictor of cognitive dysfunction, explaining 37% of the variance, whereas phosphorylated tau levels only accounted for 0.2%. Taken together, these results support the hypothesis that inflammation-induced elevation in Aß disrupts cognition, independently of phosphorylated tau, and suggest that long-term administration of poly I:C may provide a model to investigate the contribution of long-term inflammation toward the development of Alzheimer's-like pathology.

Extraction of social information from gait in schizophrenia.

BACKGROUND: The human face and body are rich sources of socio-emotional cues. Accurate recognition of these cues is central to adaptive social functioning. Past studies indicate that individuals with schizophrenia (SZ) show deficits in the perception of emotion from facial cues but the contribution of bodily cues to social perception in schizophrenia is undetermined. The present study examined the detection of social cues from human gait patterns presented by computer-generated volumetric walking figures. METHOD: A total of 22 SZ and 20 age-matched healthy control participants (CO) viewed 1 s movies of a 'digital' walker's gait and subsequently made a forced-choice decision on the emotional state (angry or happy) or the gender of the walker presented at three intensity levels. Overall sensitivity to the social cues and bias were computed. For SZ, symptom severity was assessed. RESULTS: SZ were less sensitive than CO on both emotion and gender discrimination, regardless of intensity. While impaired overall, greater signal intensity did improve performance of SZ. Neither group differed in their response bias in either condition. The discrimination sensitivity of SZ was unrelated to their social functioning or symptoms but a bias toward perceiving gait as happy was associated with better social functioning. CONCLUSIONS: These results suggest that SZ are impaired in extracting social information from gait but SZ benefited from increased signal intensity of social cues. Inaccurate perception of social cues in others may hinder adequate preparation for social interactions.

Exercise efficiency of low power output cycling.

Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations.

Door-to-balloon time: performance improvement in the multidisciplinary treatment of myocardial infarction.

The treatment of ST-elevation myocardial infarction with primary percutaneous coronary intervention is a time-sensitive process, with outcomes correlated with the speed with which the healthcare team can make the diagnosis, start preliminary treatment, and successfully perform the intervention. This requires multidisciplinary teamwork involving Emergency Medical Services, Emergency Medicine and Nursing, the cardiac catheterization laboratory team, and interventional cardiology. The success of effectively delivering treatment is enhanced through focused analysis of key steps within the care process to identify systems problems and implement quality improvement initiatives. This article reviews the process whereby our institution achieved top decile performance in this multidisciplinary treatment.

Development and validation of a fluorescent microsphere immunoassay for anti-IgA.

Anti-IgA may cause anaphylactic transfusion reactions in IgA-deficient individuals. Testing for IgG anti-IgA is useful to identify persons at risk. This report describes an immunoassay for anti-IgA that uses polyclonal IgA coupled to fluorescent microspheres as an immunosorbent. Anti-IgA is detected by phycoerythrin-labeled anti-IgG. The assay is calibrated in arbitrary units by use of a serum that contains anti-IgA. Dose-response studies with sera that contain anti-IgA showed positive responses at dilutions up to 32-fold greater than the dilution used to test patients' samples. Inhibition studies with purified IgA and IgA-deficient serum showed no inhibition with IgA-deficient serum and complete inhibition with soluble IgA. Clinical tests performed in more than 90 assays had a CV of 13.6 percent for measurements of an internal positive control. The fluorescent immunoassay method is rapid, reproducible, and sensitive to low concentrations of IgG anti-IgA.

Should physicians be allowed to use alcohol while on call?

Although physician alcohol use that leads to impairment has been extensively discussed, few statements address the issue of alcohol use of physicians who are on call. In this paper the authors review recent information on physicians' perceptions of alcohol use by themselves and their colleagues while on call. It is argued that conflicts in physicians' perceptions are due to the fact that the larger society has not addressed the question of whether drinking on call is public or private behaviour. The authors argue that when medicine is understood as a practice defined partly in terms of standards of excellence, the present approach of the American Medical Association to prohibit practicing medicine under the influence of alcohol requires a prohibition of drinking alcohol while on call, unless studies determine a clear threshold for drinking alcohol without placing patients at risk.

Intestinal mucosal immunoglobulins during human immunodeficiency virus type 1 infection.

In intestinal fluid samples from 39 human immunodeficiency virus type 1 (HIV-1)-infected patients, IgA and IgG levels were equivalent, whereas in 10 controls, IgA levels were significantly higher than those of IgG (P < .05). Intestinal IgA in patients contained predominantly monomeric IgA1, whereas IgA1 and IgA2 subclass levels in controls were nearly equivalent and primarily polymeric. The predominance of IgG and monomeric IgA1 in mucosal fluid samples from HIV-1-infected patients suggests exudation of serum immunoglobulins into the intestine. The decreased proportion of mucosal plasma cells producing IgA and IgA2 in the HIV-1-infected patients (P < .01) may also contribute to the abnormal intestinal immunoglobulin levels. Intestinal IgG reacted with most HIV-1 antigens, whereas specific IgA was present in only 10 of 17 patients and reacted with only envelope (gp120 and gp160) and, less often, core (p17 and p24) antigens. Aberrant mucosal antibody responses and decreased integrity of the mucosal barrier may contribute to the intestinal dysfunction and infections that characterize HIV-1 infection.

Epidermal growth factor receptor expression in squamous cell carcinoma of the hypopharynx.

Expression of the epidermal growth factor receptor (EGFR) has been demonstrated in normal and malignant squamous epithelia. Its presence has been suggested to be important in the pathophysiology and prognosis of epithelial cancers. Archival tumour specimens from 57 patients with squamous cell carcinoma of the hypopharynx were studied using OM-11-951, a new murine anti-EGFR monoclonal antibody which recognizes the receptor on deparaffinized tissue. By visual inspection, 28 (49%) tumours were EGFR negative; 29 (51%) tumours were EGFR positive. While patients whose tumours were EGFR positive were younger, there was no significant correlation with other clinical or pathological variables (including grade and stage). Patients whose tumours were EGFR negative had a median survival of 21 (95% CI 4.3-37.7) months compared with a median survival of 17 (95% CI 11.4-22) months for patients whose tumours were EGFR positive. The difference was not statistically significant. A multiple regression analysis did not demonstrate EGFR status to be important in predicting survival. These data cast doubt on the prognostic significance of EGFR expression in this neoplasm.

Selective elevation of monomeric IgA1 in IgA nephropathy patients with normal renal function.

The molecular form of the pathognomonic IgA in IgA nephropathy (IgAN) remains controversial. Because characterization of the molecular form of IgA molecules can lend insight into their origin (systemic v mucosal), we developed immunoassays to measure both total and J chain-containing (polymeric) IgA1 and IgA2. These assays were used to measure IgA in sera from two groups of IgAN patients (with normal or decreased renal function), as well as from a group of normal individuals. IgA1 levels were higher in both groups of patients with IgAN when compared with the controls. The elevation appeared to be restricted to non-J chain-containing (monomeric) IgA1 in patients with normal renal function, whereas polymeric IgA1 was also slightly elevated in patients whose renal function was diminished. While there were no significant differences between the groups in terms of the levels of total IgA2, the patient group with normal kidney function appeared to have lower levels of polymeric IgA2. The observation that the elevation in serum IgA appears to be restricted to the monomeric form of IgA1, at least when renal function is normal, implies a systemic origin of the pathognomonic IgA in IgAN and further suggests an abnormality in the regulation of IgA secretion by immunoglobulin-producing cells in bone marrow, the site of systemic IgA synthesis.

Electrochemiluminescence detection for development of immunoassays and DNA probe assays for clinical diagnostics.

Electrochemiluminescence (ECL) has been developed as a highly sensitive process in which reactive species are generated from stable precursors (i.e., the ECL-active label) at the surface of an electrode. This new technology has many distinct advantages over other detection systems: no radioisotopes are used; detection limits for label are extremely low (200 fmol/L); the dynamic range for label quantification extends over six orders of magnitude; the labels are extremely stable compared with those of most other chemiluminescent systems; the labels, small molecules (approximately 1000 Da), can be used to label haptens or large molecules, and multiple labels can be coupled to proteins or oligonucleotides without affecting immunoreactivity, solubility, or ability to hybridize; because the chemiluminescence is initiated electrochemically, selectivity of bound and unbound fractions can be based on the ability of labeled species to access the electrode surface, so that both separation and nonseparation assays can be set up; and measurement is simple and rapid, requiring only a few seconds. We illustrate ECL in nonseparation immunoassays for digoxin and thyrotropin and in separation immunoassays for carcinoembryonic antigen and alpha-fetoprotein. The application of ECL for detection of polymerase chain reaction products is described and exemplified by quantifying the HIV1 gag gene.

Humoral immunity in root caries in an elderly population. 1.

IgA, IgG and IgM antibody activity (ELISA Units/ml) to Streptococcus mutans, Actinomyces viscous and Escherichia coli CF8 in serum, parotid saliva and whole saliva was measured using the amplified ELISA (a-ELISA) while the concentration (microgram/ml) of each isotype of immunoglobulin as well as albumin and lactoferrin, was determined using sandwich ELISAs. Selection of suitable reagents from those commercially available was based on specificity tests using purified human immunoglobulin; most polyclonal reagents required further absorption to attain class specificity. Cross-absorption studies indicated the absence of patient antibodies that were cross-reactive among the bacteria studied, except for IgM in some cases. Expression of response in ELISA Units (E.U.) per microgram of immunoglobulin, i.e. specific activity, revealed that IgG specific activity was significantly higher in parotid saliva than in either whole saliva or serum for all bacteria studied; serum and whole saliva did not differ except for the higher specific activity in whole saliva to E. coli. The value of one E.U. was determined using the Comparative Antibody-immunoglobulin Capture Assay (CACA). Using this novel method, we estimated that about 0.05 percent of serum IgA was specific for Streptococcus mutans, 0.008 for Actinomyces viscosus and 0.004 for Escherichia coli CF8. The percentage of specific IgM antibodies was higher than for IgA and IgG. The concentration of IgA anti-Streptococcus mutans, Actinomyces viscosus and Escherichia coli levels are approximately 92 ng/ml, 25 ng/ml and 16 ng/ml in whole saliva and 46 ng/ml, 9.4 ng/ml and 6.3 ng/ml in parotid saliva.(ABSTRACT TRUNCATED AT 250 WORDS)

IgA subclasses of human colostral antibodies specific for microbial and food antigens.

The distribution of total and antigen-specific IgA1 and IgA2 antibodies in human colostrum was determined by ELISA using subclass-specific monoclonal reagents. In 18 samples of colostrum the mean ratio of total IgA1 to IgA2 was found to be 53:47, respectively, but significant individual variations were observed. In two samples we found unusually low levels of IgA1, while IgA2 was in the normal range. IgA1 and IgA2 antibody activities were determined against the following antigens: bovine gamma-globulin and beta-lactoglobulin, tetanus toxoid, protein antigen I/II of Streptococcus mutans, influenza virus vaccine, polysaccharides of pneumococcal, meningococcal and Haemophilus influenzae type b origin, and lipopolysaccharide (LPS) from Escherichia coli K235. The IgA antibody activity directed against the polysaccharides was almost equally distributed between the two subclasses. However, antibody activity specific for protein antigens was found predominantly in the IgA1 subclass while anti-LPS activity was mostly of the IgA2 subclass.

Application of theoretical considerations to the analysis of ELISA data.

Solid-phase immunoassays such as the ELISA are in routine use in many areas of biological research. Data from these assays are analyzed in a variety of ways, frequently without taking into account the immunochemical principles of the assay. The Reference Standard Method is often used and is suitable and convenient for obtaining concentration (or activity) values from the antigen-specific ELISA or spRIA, sandwich assays, and inhibition assays. The standard curve required for this method may be obtained by simple linear regression analysis of logarithmic or logitlogarithmic transformed data obtained from titration of the reference standard. The shape of the logarithmic plot of the reference standard provides information on the performance of the assay. Examining data from multiple dilutions of the samples is essential to assure that each titrates with the same slope as does the reference standard; the analysis routine must permit this comparison to be made. ELISANALYSIS is a program for the IBM PC which was developed to perform such analyses. It is presented here as a model, with sufficient information provided for the development of similar analytical routines by interested users. This approach to ELISA data analysis is presented as an alternative to complicated empirical curve-fitting systems and simple endpoint methods, which can be immunochemically misleading or, in some cases, even invalid. The consistent use of the described routines would encourage greater uniformity in the means of data interpretation and thereby enhance our understanding of immunobiology.