Molecularly imprinted nanogels as synthetic recognition materials for the ultrasensitive detection of periodontal disease biomarkers.

Periodontal disease affects supporting dental structures and ranks among one of the top most expensive conditions to treat in the world. Moreover, in recent years, the disease has also been linked to cardiovascular and Alzheimer's diseases. At present, there is a serious lack of accurate diagnostic tools to identify people at severe risk of periodontal disease progression. Porphyromonas gingivalis is often considered one of the most contributing factors towards disease progression. It produces the Arg- and Lys-specific proteases Rgp and Kgp, respectively. Within this work, a short epitope sequence of these proteases is immobilised onto a magnetic nanoparticle platform. These are then used as a template to produce high-affinity, selective molecularly imprinted nanogels, using the common monomers N-tert-butylacrylamide (TBAM), N-isopropyl acrylamide (NIPAM), and N-(3-aminopropyl) methacrylamide hydrochloride (APMA). N,N-Methylene bis(acrylamide) (BIS) was used as a crosslinking monomer to form the interconnected polymeric network. The produced nanogels were immobilised onto a planar gold surface and characterised using the optical technique of surface plasmon resonance. They showed high selectivity and affinity towards their template, with affinity constants of 79.4 and 89.7 nM for the Rgp and Kgp epitope nanogels, respectively. From their calibration curves, the theoretical limit of detection was determined to be 1.27 nM for the Rgp nanogels and 2.00 nM for the Kgp nanogels. Furthermore, they also showed excellent selectivity against bacterial culture supernatants E8 (Rgp knockout), K1A (Kgp knockout), and W50-d (wild-type) strains in complex medium of brain heart infusion (BHI).

Microcontact-Imprinted Optical Sensors for Virulence Factors of Periodontal Disease.

Periodontitis (gum disease) is a common biofilm-mediated oral condition, with around 7% of the adult population suffering from severe disease with risk for tooth loss. Moreover, periodontitis virulence markers have been found in atherosclerotic plaque and brain tissue, suggesting a link to cardiovascular and Alzheimer's diseases. The lack of accurate, fast, and sensitive clinical methods to identify patients at risk leads, on the one hand, to patients being undiagnosed until the onset of severe disease and, on the other hand, to overtreatment of individuals with mild disease, diverting resources from those patients most in need. The periodontitis-associated bacterium, Porphyromonas gingivalis, secrete gingipains which are highly active proteases recognized as key virulence factors during disease progression. This makes them interesting candidates as predictive biomarkers, but currently, there are no methods in clinical use for monitoring them. Quantifying the levels or proteolytic activity of gingipains in the periodontal pocket surrounding the teeth could enable early-stage disease diagnosis. Here, we report on a monitoring approach based on high-affinity microcontact imprinted polymer-based receptors for the Arg and Lys specific gingipains Rgp and Kgp and their combination with surface plasmon resonance (SPR)-based biosensor technology for quantifying gingipain levels in biofluids and patient samples. Therefore, Rgp and Kgp were immobilized on glass coverslips followed by microcontact imprinting of poly-acrylamide based films anchored to gold sensor chips. The monomers selected were N-isopropyl acrylamide (NIPAM), N-hydroxyethyl acrylamide (HEAA) and N-methacryloyl-4-aminobenzamidine hydrochloride (BAM), with N,N'-methylene bis(acrylamide) (BIS) as the crosslinker. This resulted in imprinted surfaces exhibiting selectivity towards their templates high affinity and selectivity for the templated proteins with dissociation constants (K d) of 159 and 299 nM for the Rgp- and Kgp-imprinted, surfaces respectively. The former surface displayed even higher affinity (K d = 71 nM) when tested in dilute cell culture supernatants. Calculated limits of detection for the sensors were 110 and 90 nM corresponding to levels below clinically relevant concentrations.

ERS International Congress 2021: highlights from the Allied Respiratory Professionals assembly.

This paper provides an overview of some of the most memorable sessions that were (co)organised by the Allied Respiratory Professionals Assembly during the 2021 European Respiratory Society International Congress, which was held online for the second consecutive year due to the COVID-19 pandemic. Early Career Members from Assembly 9 summarised the content of the sessions (three oral communication sessions, two symposia and one Expert View) with the support of the chairs from the four Assembly groups: Respiratory Function Technologists and Scientists (Group 9.01); Physiotherapists (Group 9.02); Nurses (Group 9.03); and Psychologists and Behavioural Scientists (Group 9.04). The sessions covered the following topics: impact of COVID-19 on lung function and healthcare services, and the importance of quality assurance and technology in lung function assessment; diagnosis and management of sarcopenia in patients with chronic respiratory disease; maintenance of the effects of pulmonary rehabilitation; solutions outside the hospital for the management of patients with COVID-19 in need of health care; the nursing perspective during the COVID-19 pandemic; and psychological and behavioural issues in respiratory care. This highlights article provides valuable insight into the latest scientific data and emerging areas affecting clinical practice of allied respiratory professionals.

Subcortical gray matter volumes in asthma: associations with asthma duration, control, and anxiety.

Asthma as a chronic inflammatory disease can be expected to affect central nervous system structures but little is known about subcortical structures in asthma and their potential association with illness-specific outcomes and anxiety. A total of 40 young adults (20 with asthma and 20 gender- and age-matched controls) underwent high-resolution T1-weighted MRI scan, viewed short distressing film clips, and filled in questionnaires about anxious and depressed mood, as well as asthma history, control, and catastrophizing thoughts about asthma, for those with asthma. The structural scans were processed in FSL's FIRST program to delineate subcortical structures of interest: amygdala, hippocampus, putamen, pallidum, caudate nucleus, nucleus accumbens, and thalamus. Findings showed no general reduction in subcortical gray matter volumes in asthma compared to controls. Asthma duration, asthma control, and catastrophizing of asthma and asthma attacks were negatively associated with volumes of putamen and pallidum, and to a weaker extent thalamus and amygdala, while controlling for gender, age, and corticosteroid inhaler use. In addition, stronger anxiety in response to distressing films was associated with lower volume of the pallidum, whereas general anxious and depressed mood was unrelated to subcortical structures. Thus, although there are no subcortical structural differences between young adults with asthma and healthy controls, longer asthma history, suboptimal management, and illness-related anxiety are reflected in lower gray matter volumes of subcortical structures, further emphasizing the importance of maintaining optimal asthma control.

Acquisition and generalization of cough trigger beliefs in allergic rhinitis.

In allergic conditions, trigger identification is often inaccurate, and may be influenced by pre-existing beliefs. In this study, we investigated the acquisition and generalization of symptom trigger beliefs in individuals with allergic rhinitis (n = 24) and control participants (n = 24). In a lab-based trigger acquisition task, unique exemplars of two trigger categories were either paired with saline inhalation (CS- category) or citric acid inhalation (CS+ category). The next day, we tested recognition and symptom expectancy for CS category exemplars and exemplars of novel trigger categories. Participants acquired differential symptom expectancies for CS+ compared to CS- exemplars, with faster acquisition in participants with rhinitis. Differential symptom expectancies persisted the next day, and generalized to novel trigger categories, with stronger generalization in rhinitis vs. control participants. These patterns of acquisition and generalization suggest that overgeneralization of trigger beliefs may complicate trigger identification in participants with allergic conditions.

In the spotlight: first ERS Early Career Member Award winner, the ERS Lung Science Conference 2020 and new ECMC members.

All you need to know about @LiesLahousse, first ECM to be granted the Early Career Member Award; #LSC2020; the newly elected assembly representatives for @EarlyCareerERS; and new @EuroRespSoc fellowship opportunities http://bit.ly/2OTgQlo.

Placebo and nocebo effects and operant pain-related avoidance learning.

INTRODUCTION: Research on learning in placebo and nocebo has relied predominantly on Pavlovian conditioning procedures. Operant learning procedures may more accurately model learning in real-life situations in which placebo and nocebo effects occur. OBJECTIVES: To investigate the development and persistence of placebo and nocebo effects using an operant avoidance learning task. METHODS: Pain-free participants (n = 58) could learn to avoid pain by performing movements that differed in difficulty and intensity of painful stimulation. Participants performed movements in 2 contexts. In the high cost of avoidance context, pain stimulus intensity reduced with increasing movement difficulty. In the low cost of avoidance context, contingencies were reversed. Participants rated pain expectations and pain intensity. During test, movement difficulties were unchanged, but participants always received a medium-intensity pain stimulus. Placebo and nocebo effects were defined as lower/higher pain intensity ratings for trajectories that previously resulted in low/high-intensity compared with medium-intensity stimulation. RESULTS: As expected, participants acquired differential movement-pain expectations and differential movement choices. Testing with a medium-intensity pain stimulus quickly erased differences in movement choice across contexts, but differences in pain expectations were maintained. Pain modulation across context was in line with movement-pain expectations. However, we only observed placebo effects within the low cost of avoidance context and found no evidence of nocebo effects. CONCLUSION: Operant learning can change pain expectations, pain modulation, and pain-related avoidance behavior. Persisting pain expectations suggest that acquired pain beliefs may be resistant to disconfirmation, despite self-initiated experience with novel pain-movement contingencies.

Impact of Disease-Specific Fears on Pulmonary Rehabilitation Trajectories in Patients with COPD.

Disease-specific fears predict health status in chronic obstructive pulmonary disease (COPD), but their role in pulmonary rehabilitation (PR) remains poorly understood and especially longer-term evaluations are lacking. We therefore investigated changes in disease-specific fears over the course of PR and six months after PR, and investigated associations with PR outcomes (COPD assessment test (CAT) and St. Georges respiratory questionnaire (SGRQ)) in a subset of patients with COPD (n = 146) undergoing a 3-week inpatient PR program as part of the STAR study (Clinicaltrials.gov, ID: NCT02966561). Disease-specific fears as measured with the COPD anxiety questionnaire improved after PR. For fear of dyspnea, fear of physical activity and fear of disease progression, improvements remained significant at six-month follow-up. Patients with higher disease-specific fears at baseline showed elevated symptom burden (CAT and SGRQ Symptom scores), which persisted after PR and at follow-up. Elevated disease-specific fears also resulted in reduced improvements in Quality of Life (SGRQ activity and impact scales) after PR and at follow-up. Finally, improvement in disease-specific fears was associated with improvement in symptom burden and quality of life. Adjustment for potential confounding variables (sex, smoking status, age, lung function, and depressive symptoms) resulted in comparable effects. These findings show the role of disease-specific fears in patients with COPD during PR and highlight the need to target disease-specific fears to further improve the effects of PR.

Assessment of Anterior Cruciate Ligament Graft Maturity With Conventional Magnetic Resonance Imaging: A Systematic Literature Review.

BACKGROUND: Magnetic resonance imaging (MRI) signal intensity (SI) measurements are being used increasingly in both clinical and research studies to assess the maturity of anterior cruciate ligament (ACL) grafts in humans. However, SI in conventional MRI with weighted images is a nonquantitative measure dependent on hardware and software. PURPOSE: To conduct a systematic review of studies that have used MRI SI as a proxy for ACL graft maturity and to identify potential confounding factors in assessing the ACL graft in conventional MRI studies. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was conducted by searching the MEDLINE/PubMed, Scopus, and Cochrane Library electronic databases according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify studies that examined the healing of the intra-articular portion of the ACL graft by assessing SI on MRIs. RESULTS: A total of 34 studies were selected for inclusion in this systematic review. The MRI acquisition techniques and methods to evaluate the ACL graft SI differed greatly across the studies. No agreement was found regarding the time frames of SI changes in MRI reflecting normal healing of the ACL tendon graft, and the graft SI and clinical outcomes after ACL reconstruction were found to be poorly correlated. CONCLUSION: The MRI acquisition and evaluation methods used to assess ACL grafts are very heterogeneous, impeding comparisons of SI between successive scans and between independent studies. Therefore, quantitative MRI-based biomarkers of ACL graft healing are greatly needed to guide the appropriate time of returning to sports after ACL reconstruction.

In Vivo Identification of Thick, Thin, and Pale Stripes of Macaque Area V2 Using Submillimeter Resolution (f)MRI at 3 T.

Primate area V2 contains a repetitive pattern of thick, thin and pale cytochrome oxidase stripes that are characterized by largely discrete in- and output channels, as well as differences in function, and myelo- and cytoarchitecture. Stripes have been identified mainly using microscope-based imaging of tiny portions of superficially located V2, or by postmortem methods, hence, the quest for (quasi) noninvasive tools to study these mesoscale functional units. Only recently, stripe-like V2 patterns have been demonstrated in humans with high-field (functional) magnetic resonance imaging (f)MRI, but in both such studies only 2 stripe compartments could be identified. Although interstripe distances in monkeys are ~half of those in humans, we show that all 3 V2 stripe classes can be reliably separated using submillimeter (f)MRI (0.6 mm isotropic voxels) on regular 3 T scanners by combining contrast agents and implanted phased-array coils. Specifically, we show highly reproducible fMRI patterns, both within and across subjects, of color-selective thin and disparity-selective thick stripes. Furthermore, reliable MRI-based higher myelin-density was observed in pale stripes. Hence, this is the first study showing segregation of columns using (f)MRI-based methods in macaque cortex, which opens the possibility of studying these elementary building blocks of the visual system noninvasively on a large scale.

Towards an assessment of perceived COPD exacerbation triggers: Initial development and validation of a questionnaire.

BACKGROUND AND OBJECTIVE: Prevention of exacerbations in chronic obstructive pulmonary disease (COPD) is important to decrease overall declines in functioning and improve quality of life. The present study sought to develop a psychometrically valid measure of perceived triggers of exacerbations in COPD patients, the COPD Exacerbation Trigger Inventory (CETI). METHODS: Participants (n = 192) were recruited through local clinics and online to complete surveys of the CETI, demographic information, disease-specific information and the COPD Assessment Test (CAT). The CETI included a free response section on patients' individual top triggers, combined with ratings of their controllability. RESULTS: Exploratory principal component analyses identified a stable 5-factor structure (33 items), from which trigger subscales for weather/climate, air pollution/irritants, exercise, infection/illness and psychological factors were formed (internal consistency Cronbach's α = 0.90-0.94). Trigger factors were associated with COPD functional status, exacerbation frequency and healthcare utilization. Participants found personal triggers related to dust, air pollution, smoking and physical activity to be the most easily controlled, whereas those related to psychological factors, climate, infection, respiratory symptoms and sleep to be more difficult to control. Greater perceived controllability of triggers was associated with lower CAT scores, indicating better health status and less impact of the disease on functioning. CONCLUSION: The CETI is a psychometrically valid measure of perceived exacerbation triggers in patients with COPD. Perceived triggers are associated with clinical outcomes. Assessment of trigger classes and their controllability may prove useful in both research and clinical settings with COPD patients and to further our knowledge in prevention and disease management.

Learning to Detect Triggers of Airway Symptoms: The Role of Illness Beliefs, Conceptual Categories and Actual Experience with Allergic Symptoms.

Background: In asthma and allergic rhinitis, beliefs about what triggers allergic reactions often do not match objective allergy tests. This may be due to insensitivity for expectancy violations as a result of holding trigger beliefs based on conceptual relationships among triggers. In this laboratory experiment, we aimed to investigate how pre-existing beliefs and conceptual relationships among triggers interact with actual experience when learning differential symptom expectations. Methods: Healthy participants (N = 48) received information that allergic reactions were a result of specific sensitivities versus general allergic vulnerability. Next, they performed a trigger learning task using a differential conditioning paradigm: brief inhalation of CO2 enriched air was used to induce symptoms, while participants were led to believe that the symptoms came about as a result of inhaled allergens (conditioned stimuli, CS's; CS+ followed by symptoms, CS- not followed by symptoms). CS+ and CS- stimuli either shared (e.g., birds-mammals) or did not share (e.g. birds-fungi) category membership. During Acquisition, participants reported symptom expectancy and symptom intensity for all triggers. During a Test 1 day later, participants rated symptom expectancies for old CS+/CS- triggers, for novel triggers within categories, and for exemplars of novel trigger categories. Data were analyzed using multilevel models. Findings: Only a subgroup of participants (n = 22) showed differences between CO2 and room air symptoms. In this group of responders, analysis of symptom expectancies during acquisition did not result in significant differential symptom CS+/CS- acquisition. A retention test 1 day later showed differential CS+/CS- symptom expectancies: When CS categories did not share category membership, specific sensitivity beliefs improved retention of CS+/CS- differentiation. However, when CS categories shared category membership, general vulnerability beliefs improved retention of CS+/CS- differentiation. Furthermore, participants showed some selectivity in generalization of symptom expectancies to novel categories, as symptom expectancies did not generalize to novel categories that were unrelated to CS+ or CS- categories. Generalization to novel categories was not affected by information about general vulnerability or specific sensitivities. Discussion: Pre-existing vulnerability beliefs and conceptual relationships between trigger categories influence differential symptom expectancies to allergic triggers.

Immunohistochemical Profiling of Corneas With Fuchs Endothelial Corneal Dystrophy.

PURPOSE: Fuchs endothelial corneal dystrophy (FECD) is the leading indication for endothelial keratoplasty. Further insight into its pathophysiology is needed to develop alternative therapies. METHODS: Sixteen genes from a previous microarray expression experiment (FECD vs. normal) were validated using immunohistochemistry on paraffin-embedded corneas (n = 6 FECD, n = 6 normal). The results were quantified manually and semiautomatically. RESULTS: A higher percentage of corneal endothelial cells stained for alpha-smooth muscle actin (αSMA), cytokeratin 7, and superoxide dismutase 3 in FECD versus normal [odds ratios (ORs) of 60.90, 41.70, and 15.16, respectively, P < 0.001]. Dot-like staining for major histocompatibility complex, class II, DR alpha was present in FECD, but not in normal. Higher percentages of stromal cells in FECD versus normal stained for αSMA (OR = 864.26, P < 0.001), brain-derived neurotrophic factor (BDNF, OR = 6.34, P = 0.005), fibroblast growth factor 7 (FGF-7, OR = 2.76, P = 0.011), FGF-9 (OR = 5.97, P < 0.001), receptor FGFR-3 (OR = 13.90, P = < 0.001), and serum amyloid A1 (OR = 3.45, P = 0.023). Higher percentages of corneal epithelial cells stained for αSMA (OR = 2.20, P = 0.006) and BDNF (OR = 3.94, P < 0.001) in FECD versus normal. CONCLUSIONS: These results support a role for epithelial-mesenchymal transition (αSMA), oxidative stress (superoxide dismutase 3), and major histocompatibility complex, class II, DR alpha cells with dendritic morphology in the pathophysiology of FECD. Furthermore, corneal stromal cells express trophic molecules (BDNF and FGFs) and markers of chronic inflammation (serum amyloid A1) in FECD.

Airway reactivity in response to repeated emotional film clip presentation in asthma.

Emotional stimuli elicit airway constriction in individuals with asthma and in healthy individuals, but little is known about effects of repeated stimulation. We therefore explored the effect of repeated emotion induction on respiratory resistance (Rrs) using unpleasant, high-arousal surgery films and investigated effects of respiration and emotional reactivity. Twenty-six participants (13 with asthma) watched a series of 12 short, 45-s surgery films followed by 2-min recovery periods. Rrs assessed with impulse oscillometry was significantly elevated during films in both groups compared to baseline and recovered quickly after that. No habituation of airway responses occurred. Rrs was higher in participants who felt more aroused and less in control when watching the films. Changes in Rrs remained significant when controlling for changes in respiration or emotional experience. Thus, although unpleasant stimuli lead to elevated Rrs, airway obstruction is not exacerbated with repeated stimulation due to a fast return to baseline after stimulation.

Premorbid obesity, but not nutrition, prevents critical illness-induced muscle wasting and weakness.

BACKGROUND: The 'obesity paradox' of critical illness refers to better survival with a higher body mass index. We hypothesized that fat mobilized from excess adipose tissue during critical illness provides energy more efficiently than exogenous macronutrients and could prevent lean tissue wasting. METHODS: In lean and premorbidly obese mice, the effect of 5 days of sepsis-induced critical illness on body weight and composition, muscle wasting, and weakness was assessed, each with fasting and parenteral feeding. Also, in lean and overweight/obese prolonged critically ill patients, markers of muscle wasting and weakness were compared. RESULTS: In mice, sepsis reduced body weight similarly in the lean and obese, but in the obese with more fat loss and less loss of muscle mass, better preservation of myofibre size and muscle force, and less loss of ectopic lipids, irrespective of administered feeding. These differences between lean and obese septic mice coincided with signs of more effective hepatic fatty acid and glycerol metabolism, and ketogenesis in the obese. Also in humans, better preservation of myofibre size and muscle strength was observed in overweight/obese compared with lean prolonged critically ill patients. CONCLUSIONS: During critical illness premorbid obesity, but not nutrition, optimized utilization of stored lipids and attenuated muscle wasting and weakness.

Effects of Symptom Perception Interventions on Trigger Identification and Quality of Life in Children with Asthma.

BACKGROUND: Management of individual triggers is suboptimal in practice. In this project, we investigated the impact of symptom perception interventions on asthma trigger identification and self-reported asthma quality of life. METHODS: Children with asthma (n=227) participated in three asthma education sessions and then were randomized first to one of three home monitoring conditions (symptom monitoring and peak flow training with feedback, peak flow training without feedback, or no peak flow training) and then subsequently to one of three resistive load discrimination training conditions (signal detection training with feedback, signal detection training without feedback, or no training). Triggers were reported at enrollment, following home monitoring, and following discrimination training; quality of life was measured after home monitoring and after resistive load testing. RESULTS: Symptom perception interventions resulted in increases in reported triggers, which increased reliably as a function of home monitoring, and increased further in participants who completed discrimination training with feedback. Increases in the number of reported asthma triggers were associated with decreases in quality of life. DISCUSSION: Patients may benefit from strategies that make trigger-symptom contingencies clear. Complementary strategies are needed to address changes in the perceived burden of asthma which comes from awareness of new asthma triggers.

Generalization of Respiratory Symptom Triggers.

Behavioral management of asthma and other chronic conditions depends upon the accurate identification of environmental factors that trigger symptom onset. In this study, we developed a lab-based conditioning method to study category-based acquisition and generalization of respiratory symptom triggers. During trigger acquisition, unique exemplars of two different categories were shown to a sample of healthy participants (n=48). CS+ exemplars were paired with CO2 inhalation on 50% of trials, while CS- exemplars were always paired with room air. Trigger categories differed in their conceptual similarity. In a generalization task, participants rated symptom expectancy for a set of triggers that included previously seen exemplars, novel exemplars, and exemplars from novel categories. Results show that participants acquired differential symptom expectancies based on category information, which generalized to novel CS+ exemplars and novel categories that shared similarity with the CS+ category. Greater similarity between CS+ and CS- categories increased differential effects for both old and novel exemplars of CS+ and CS- categories, and increased the proportion of novel CS+ exemplars that were remembered as being seen during acquisition. These findings suggest that a more narrowly defined contrast between triggers and nontriggers promotes category-based inference and could help to reduce uncertainty about potential triggers.

Covert shifts of spatial attention in the macaque monkey.

In the awake state, shifts of spatial attention alternate with periods of sustained attention at a fixed location or object. Human fMRI experiments revealed the critical role of the superior parietal lobule (SPL) in shifting spatial attention, a finding not predicted by human lesion studies and monkey electrophysiology. To investigate whether a potential homolog of the human SPL shifting region exists in monkeys (Macaca mulatta), we adopted an event-related fMRI paradigm that closely resembled a human experiment (Molenberghs et al., 2007). In this paradigm, a pair of relevant and irrelevant shapes was continuously present on the horizontal meridian. Subjects had to covertly detect a dimming of the relevant shape while ignoring the irrelevant dimmings. The events of interest consisted of the replacement of one stimulus pair by the next. During shift but not stay events, the relevant shape of the new pair appeared at the contralateral position relative to the previous one. Spatial shifting events activated parietal areas V6/V6A and medial intraparietal area, caudo-dorsal visual areas, the most posterior portion of the superior temporal sulcus, and several smaller frontal areas. These areas were not activated during passive stimulation with the same sensory stimuli. During stay events, strong direction-sensitive attention signals were observed in a distributed set of contralateral visual, temporal, parietal, and lateral prefrontal areas, the vast majority overlapping with the sensory stimulus representation. We suggest medial intraparietal area and V6/V6A as functional counterparts of human SPL because they contained the most widespread shift signals in the absence of contralateral stay activity, resembling the functional characteristics of the human SPL shifting area.