Identification of a Noxo1 inhibitor by addition of a polyethylene glycol chain.

Reactive oxygen species (ROS) are a heterogeneous group of highly reactive ions and molecules derived from molecular oxygen (O2) which can cause DNA damage and lead to skin cancer. NADPH oxidase 1 (Nox1) is a major producer of ROS in the skin upon exposure to ultraviolet light. Functionally, Nox1 forms a holoenzyme complex that generates two superoxide molecules and reduces NADPH. The signaling activation occurs when the organizer subunit Noxo1 translocates to the plasma membrane bringing a cytochrome p450, through interaction with Cyba. We propose to design inhibitors that prevent Cyba-Noxo1 binding as a topical application to reduce UV-generated ROS in human skin cells. Design started from an apocynin backbone structure to generate a small molecule to serve as an anchor point. The initial compound was then modified by addition of a polyethylene glycol linked biotin. Both inhibitors were found to be non-toxic in human keratinocyte cells. Further in vitro experiments using isothermal calorimetric binding quantification showed the modified biotinylated compound bound Noxo1 peptide with a KD of 2 nM. Both using isothermal calorimetric binding and MALDI (TOF) MS showed that binding of a Cyba peptide to Noxo1 was blocked. In vivo experiments were performed using donated skin explants with topical application of the two inhibitors. Experiments show that ultraviolet light exposure of with the lead compound was able to reduce the amount of cyclobutene pyrimidine dimers in DNA, a molecule known to lead to carcinogenesis. Further synthesis showed that the polyethylene glycol but not the biotin was essential for inhibition.

The prevalence of sarcopenia in Parkinson's disease and related disorders- a systematic review.

BACKGROUND: The prevalence of sarcopenia (reduced skeletal muscle strength and mass), Parkinson's disease (PD) and Parkinson's related disorders (PRD) all increase with age. They also share risk factors and pathogenetic features. An increased prevalence of sarcopenia in PD and PRD than the general population was thus postulated. METHODS: Four databases were searched using predefined literature search strategies. Studies conducted in participants with PD or PRD reporting the prevalence of sarcopenia and those providing data to compute the prevalence were included. Pre-sarcopenia, probable/possible sarcopenia and confirmed sarcopenia were defined according to the main sarcopenia working groups. Risk of bias was assessed using the AXIS tool. RESULTS: 1978 studies were identified; 97 assessed in full; 14 met inclusion criteria. The median study quality score was 15/20. The range of probable sarcopenia was 23.9 to 66.7%, and it did not change after excluding PRD participants. The prevalence of confirmed sarcopenia in participants with any parkinsonian disorder ranged from 2 to 31.4%. Including just PD participants, the range was 10.9 to 31.4%. In studies with controls, sarcopenia was more prevalent in PD and PRD. There was a positive non-significant trend between severity of motor symptoms and prevalence of sarcopenia or components of sarcopenia. High heterogeneity precluded meta-analysis, therefore there was insufficient evidence to conclude whether sarcopenia is more prevalent in PD or PRD. CONCLUSIONS: Probable and confirmed sarcopenia are common in PD and PRD and they may be associated with disease severity. This co-occurrence supports the value of screening for sarcopenia in parkinsonian populations.

A novel CD34-specific T-cell engager efficiently depletes acute myeloid leukemia and leukemic stem cells in vitro and in vivo.

Less than a third of patients with acute myeloid leukemia (AML) are cured by chemotherapy and/or hematopoietic stem cell transplantation, highlighting the need to develop more efficient drugs. The low efficacy of standard treatments is associated with inadequate depletion of CD34+ blasts and leukemic stem cells, the latter a drug-resistant subpopulation of leukemia cells characterized by the CD34+CD38- phenotype. To target these drug-resistant primitive leukemic cells better, we have designed a CD34/CD3 bi-specific T-cell engager (BTE) and characterized its anti-leukemia potential in vitro, ex vivo and in vivo. Our results show that this CD34-specific BTE induces CD34-dependent T-cell activation and subsequent leukemia cell killing in a dose-dependent manner, further corroborated by enhanced T-cell-mediated killing at the singlecell level. Additionally, the BTE triggered efficient T-cell-mediated depletion of CD34+ hematopoietic stem cells from peripheral blood stem cell grafts and CD34+ blasts from AML patients. Using a humanized AML xenograft model, we confirmed that the CD34-specific BTE had in vivo efficacy by depleting CD34+ blasts and leukemic stem cells without side effects. Taken together, these data demonstrate that the CD34-specific BTE has robust antitumor effects, supporting development of a novel treatment modality with the aim of improving outcomes of patients with AML and myelodysplastic syndromes.

Identification of Endothelial Proteins in Plasma Associated With Cardiovascular Risk Factors.

OBJECTIVE: Endothelial cell (EC) dysfunction is a well-established response to cardiovascular disease risk factors, such as smoking and obesity. Risk factor exposure can modify EC signaling and behavior, leading to arterial and venous disease development. Here, we aimed to identify biomarker panels for the assessment of EC dysfunction, which could be useful for risk stratification or to monitor treatment response. Approach and Results: We used affinity proteomics to identify EC proteins circulating in plasma that were associated with cardiovascular disease risk factor exposure. Two hundred sixteen proteins, which we previously predicted to be EC-enriched across vascular beds, were measured in plasma samples (N=1005) from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study) pilot. Thirty-eight of these proteins were associated with body mass index, total cholesterol, low-density lipoprotein, smoking, hypertension, or diabetes. Sex-specific analysis revealed that associations predominantly observed in female- or male-only samples were most frequently with the risk factors body mass index, or total cholesterol and smoking, respectively. We show a relationship between individual cardiovascular disease risk, calculated with the Framingham risk score, and the corresponding biomarker profiles. CONCLUSIONS: EC proteins in plasma could reflect vascular health status.

Identification of asthma phenotypes based on extrapulmonary treatable traits.

Asthma is a heterogeneous and complex disease, and a description of asthma phenotypes based on extrapulmonary treatable traits has not been previously reported.The objective of this study was to identify and characterise clusters based on clinical, functional, anthropometrical and psychological characteristics in participants with moderate-to-severe asthma.This was a cross-sectional multicentre study involving centres from Brazil and Australia. Participants (n=296) with moderate-to-severe asthma were consecutively recruited. Physical activity and sedentary time, clinical asthma control, anthropometric data, pulmonary function and psychological and health status were evaluated. Participants were classified by hierarchical cluster analysis and the clusters compared using ANOVA, Kruskal--Wallis and Chi-squared tests. Multiple logistic and linear regression models were performed to evaluate the association between variables.We identified four clusters: 1) participants with controlled asthma who were physically active; 2) participants with uncontrolled asthma who were physically inactive and more sedentary; 3) participants with uncontrolled asthma and low physical activity, who were also obese and experienced anxiety and/or depression symptoms; and 4) participants with very uncontrolled asthma who were physically inactive, more sedentary, obese and experienced anxiety and/or depression symptoms. Higher levels of sedentary time, female sex and anxiety symptoms were associated with increased odds of exacerbation risk, while being more active showed a protective factor for hospitalisation. Asthma control was associated with sex, the occurrence of exacerbation, physical activity and health status.Physical inactivity, obesity and symptoms of anxiety and/or depression were associated with worse asthma outcomes, and closely and inextricably associated with asthma control. This cluster analysis highlights the importance of assessing extrapulmonary traits to improve personalised management and outcomes for people with moderate and severe asthma.

Targeting treatable traits in severe asthma: a randomised controlled trial.

RATIONALE: Treatable traits have been proposed as a new paradigm for airway disease management. OBJECTIVES: To characterise treatable traits in a severe asthma population and to determine the efficacy of targeting treatments to these treatable traits in severe asthma. METHODS: Participants (n=140) with severe asthma were recruited to a cross-sectional study and underwent a multidimensional assessment to characterise treatable traits. Eligible participants with severe asthma (n=55) participated in a 16-week parallel-group randomised controlled trial to determine the feasibility and efficacy of management targeted to predefined treatable traits, compared to usual care in a severe asthma clinic. The patient-reported outcome of health-related quality of life was the trial's primary end-point. MAIN RESULTS: Participants with severe asthma had a mean±sd of 10.44±3.03 traits per person, comprising 3.01±1.54 pulmonary and 4.85±1.86 extrapulmonary traits and 2.58±1.31 behavioural/risk factors. Individualised treatment that targeted the traits was feasible and led to significantly improved health-related quality of life (0.86 units, p<0.001) and asthma control (0.73, p=0.01). CONCLUSIONS: Multidimensional assessment enables detection of treatable traits and identifies a significant trait burden in severe asthma. Targeting these treatable traits using a personalised-medicine approach in severe asthma leads to improvements in health-related quality of life, asthma control and reduced primary care acute visits. Treatable traits may be an effective way to address the complexity of severe asthma.

Estimation of equilibrium times and maximum capacity of adsorption of heavy metals by E. crassipes (review).

Cellulose emerges as an alternative for the treatment of water contaminated with heavy metals due to its abundant biomass and its proven potential in the adsorption of pollutants. The aquatic plant Eichhornia crassipes is an option as raw material in the contribution of cellulose due to its enormous presence in contaminated wetlands, rivers, and lakes. The efficiency in the removal of heavy metals is due to the cation exchange between the hydroxyl groups and carboxyl groups present in the biomass of E. crassipes with heavy metals. Through different chemical and physical transformations of the biomass of E. crassipesThe objective of this review article is to provide a discussion on the different mechanisms of adsorption of the biomass of E. crassipes to retain heavy metals and dyes. In addition to estimating equilibrium, times through kinetic models of adsorption and maximum capacities of this biomass through equilibrium models with isotherms, in order to design one biofilter for treatment systems on a larger scale represented the effluents of a real industry.

Systematic Development of Sandwich Immunoassays for the Plasma Secretome.

The plasma proteome offers a clinically useful window into human health. Recent advances from highly multiplexed assays now call for appropriate pipelines to validate individual candidates. Here, a workflow is developed to build dual binder sandwich immunoassays (SIA) and for proteins predicted to be secreted into plasma. Utilizing suspension bead arrays, ≈1800 unique antibody pairs are first screened against 209 proteins with recombinant proteins as well as EDTA plasma. Employing 624 unique antibodies, dilution-dependent curves in plasma and concentration-dependent curves of full-length proteins for 102 (49%) of the targets are obtained. For 22 protein assays, the longitudinal, interindividual, and technical performance is determined in a set of plasma samples collected from 18 healthy subjects every third month over 1 year. Finally, 14 of these assays are compared with with SIAs composed of other binders, proximity extension assays, and affinity-free targeted mass spectrometry. The workflow provides a multiplexed approach to screen for SIA pairs that suggests using at least three antibodies per target. This design is applicable for a wider range of targets of the plasma proteome, and the assays can be applied for discovery but also to validate emerging candidates derived from other platforms.

Physical activity associates with disease characteristics of severe asthma, bronchiectasis and COPD.

BACKGROUND AND OBJECTIVE: Physical activity (PA) in obstructive airway diseases (OAD) is likely to be impaired but this has not been extensively studied outside of chronic obstructive pulmonary disease (COPD). We describe PA levels in severe asthma and bronchiectasis compared to moderate-severe COPD and to controls, and tested the cross-sectional associations of PA (steps/day) with shared disease characteristics in the OAD group. METHODS: Adults with OAD (severe asthma = 62, COPD = 67, bronchiectasis = 60) and controls (n = 63) underwent a multidimensional assessment, including device-measured PA levels. RESULTS: The OAD group included 189 participants (58.7% females), with median (interquartile range) age of 67 (58-72) years and mean forced expiratory volume in the first second (FEV1 ) % predicted of 69.4%. Demographic characteristics differed between groups. Compared to controls (52.4% females, aged 55 (34-64) years, median 7640 steps/day), those with severe asthma, bronchiectasis and COPD accumulated less steps/day: median difference of -2255, -2289, and -4782, respectively (P ≤ 0.001). Compared to COPD, severe asthma and bronchiectasis participants accumulated more steps/day: median difference of 2375 and 2341, respectively (P ≤ 0.001). No significant differences were found between the severe asthma and bronchiectasis group. Exercise capacity, FEV1 % predicted, dyspnoea and systemic inflammation differed between groups, but were each significantly associated with steps/day in OAD. In the multivariable model adjusted for all disease characteristics, exercise capacity and FEV1 % predicted remained significantly associated. CONCLUSION: PA impairment is common in OAD. The activity level was associated with shared characteristics of these diseases. Interventions to improve PA should be multifactorial and consider the level of impairment and the associated characteristics.

PDGFB, a new candidate plasma biomarker for venous thromboembolism: results from the VEREMA affinity proteomics study.

There is a clear clinical need for high-specificity plasma biomarkers for predicting risk of venous thromboembolism (VTE), but thus far, such markers have remained elusive. Utilizing affinity reagents from the Human Protein Atlas project and multiplexed immuoassays, we extensively analyzed plasma samples from 2 individual studies to identify candidate protein markers associated with VTE risk. We screened plasma samples from 88 VTE cases and 85 matched controls, collected as part of the Swedish "Venous Thromboembolism Biomarker Study," using suspension bead arrays composed of 755 antibodies targeting 408 candidate proteins. We identified significant associations between VTE occurrence and plasma levels of human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1), von Willebrand factor (VWF), glutathione peroxidase 3 (GPX3), and platelet-derived growth factor ß (PDGFB). For replication, we profiled plasma samples of 580 cases and 589 controls from the French FARIVE study. These results confirmed the association of VWF and PDGFB with VTE after correction for multiple testing, whereas only weak trends were observed for HIVEP1 and GPX3. Although plasma levels of VWF and PDGFB correlated modestly (ρ ∼ 0.30) with each other, they were independently associated with VTE risk in a joint model in FARIVE (VWF P < .001; PDGFB P = .002). PDGFΒ was verified as the target of the capture antibody by immunocapture mass spectrometry and sandwich enzyme-linked immunosorbent assay. In conclusion, we demonstrate that high-throughput affinity plasma proteomic profiling is a valuable research strategy to identify potential candidate biomarkers for thrombosis-related disorders, and our study suggests a novel association of PDGFB plasma levels with VTE.

Evaluation of the ability of standardized supports to improve public health response to syndromic surveillance for respiratory diseases in Canada.

BACKGROUND: Despite widespread implementation of syndromic surveillance systems within public health agencies, previous studies of the implementation and use of these systems have indicated that the functions and responses taken in response to syndromic surveillance data vary widely according to local context and preferences. The objective of the Syndromic Surveillance Evaluation Study was to develop and implement standardized supports in local public health agencies in Ontario, Canada, and evaluate the ability of these supports to affect actions taken as part of public health communicable disease control programs. METHODS: Local public health agencies (LPHA) in Ontario, which used syndromic surveillance based on emergency department visits for respiratory disease, were recruited and randomly allocated to the study intervention or control group. The intervention group health agencies received standardized supports in terms of a standardized aberrant event detection algorithm and a response protocol dictating steps to investigate and assess the public health significance of syndromic surveillance alerts. The control group continued with their pre-existing syndromic surveillance infrastructure and processes. Outcomes were assessed using logbooks, which collected quantitative and qualitative information about alerts received, investigation steps taken, and public health responses. The study was conducted prospectively for 15 months (October 2013 to February 2015). RESULTS: Fifteen LPHAs participated in the study (n = 9 intervention group, n = 6 control group). A total of 1,969 syndromic surveillance alerts were received by all LPHAs. Variations in the types and amount of responses varied by LPHA, in particularly differences were noted by the size of the health unit. Smaller health units had more challenges to both detect and mount a response to any alerts. LPHAs in the control group were more likely to declare alerts to have public health significance and to initiate any action. Regression models using repeated measures showed an interaction between the year (Year 1 versus Year 2) and the intervention as well as an interaction between year and sustained nature of the alert. Both of these were linked to the control health units reporting more "watchful waiting". CONCLUSIONS: This study raises questions about the effectiveness of using standardized protocols to improve the performance of syndromic surveillance in a decentralized public health system. Despite efforts to create standardized protocols and engage public health agencies in the process, no significant differences in the effective use of syndromic alerts were observed beyond year 1. It also raises questions about the minimum capacity of the agency and minimum population size that are required for an effective response.

Enhanced cognitive flexibility in reversal learning induced by removal of the extracellular matrix in auditory cortex.

During brain maturation, the occurrence of the extracellular matrix (ECM) terminates juvenile plasticity by mediating structural stability. Interestingly, enzymatic removal of the ECM restores juvenile forms of plasticity, as for instance demonstrated by topographical reconnectivity in sensory pathways. However, to which degree the mature ECM is a compromise between stability and flexibility in the adult brain impacting synaptic plasticity as a fundamental basis for learning, lifelong memory formation, and higher cognitive functions is largely unknown. In this study, we removed the ECM in the auditory cortex of adult Mongolian gerbils during specific phases of cortex-dependent auditory relearning, which was induced by the contingency reversal of a frequency-modulated tone discrimination, a task requiring high behavioral flexibility. We found that ECM removal promoted a significant increase in relearning performance, without erasing already established-that is, learned-capacities when continuing discrimination training. The cognitive flexibility required for reversal learning of previously acquired behavioral habits, commonly understood to mainly rely on frontostriatal circuits, was enhanced by promoting synaptic plasticity via ECM removal within the sensory cortex. Our findings further suggest experimental modulation of the cortical ECM as a tool to open short-term windows of enhanced activity-dependent reorganization allowing for guided neuroplasticity.

[Presence of lactoferrin (LF) in lymphocutaneous sporotrichosis. Yeast-bound antimicrobial peptide]. / Presencia de lactoferrina (LF) en la esporotricosis linfocutánea. Péptido antimicrobiano unido a levaduras.

Sporotrichosis is a common subcutaneous mycosis in Latin America, produced by dimorphic fungi belong to Sporothrix schenckii complex of cryptic species. Infection is acquired by traumatic inoculation with contaminated organic material. Host immune response includes polymorphonuclear neutrophils chemotaxis and release of granular components. Lactoferrin is a protein member of the transferrin family of iron-binding proteins, present inside polymorphonuclear granular structure, and has been reported to affect growth and development of infectious agents, including fungal organisms. Nevertheless, lactoferrin expression in sporotrichosis infections has not been reported yet. OBJECTIVE: To determine the expression of lactoferrin using immunohistochemical staining in sporotrichosis human infection. MATERIAL AND METHODS: The dermatology department's files during a period of five years were reviewed; cases with a diagnosis of sporotrichosis were selected and lactoferrin immunostaining was performed when enough biological material was available. RESULTS: Three cases with a diagnosis of sporotrichosis and adequate biological material on paraffin block were identified. In all cases, lactoferrin immunostaining was positive around yeast cell.

The influence of socioeconomic status on future risk for developing Type 2 diabetes in the Canadian population between 2011 and 2022: differential associations by sex.

BACKGROUND: Articulating future risk of diabetes at the population level can inform prevention strategies. While previous studies have characterized diabetes burden according to socioeconomic status (SES), none have studied future risk. METHODS: We quantified the influence of multiple constructs of SES on future diabetes risk using the Diabetes Population Risk Tool (DPoRT), a validated risk prediction algorithm that generates 10-year rates of new diabetes cases. We applied DPoRT to adults aged 30-64 in the 2011-2012 Canadian Community Health Survey (n = 65,372) and calculated risk for 2021-22. A multi-category outcome was created classifying risk as low (≤5%), moderate (greater than 5% and less than 20%), and high (≥20%), then assessed the impact of individual-level SES indicators, and area-level measures of marginalization on being moderate or high risk using multinomial logistic regression, stratified by sex. RESULTS: We found nuanced profiles of social determinants by sex, where women are more sensitive to social context. Women living in households where highest educational attainment was less than secondary school were at greater risk [odds ratio (OR) of high compared to low diabetes risk 3.10, 95% confidence interval (CI) 2.19-4.40, p < 0.0001). The same relationship was less pronounced for males (OR 2.17, 95% CI 1.42-3.32, p = 0.0004). Lower household income and being food insecure predicted high future diabetes risk for women (OR 1.37, 95% CI 1.01-1.86, p = 0.0418 comparing quintile 1 to quintile 5; OR 2.64, 95% CI 1.78-3.92, p < 0.0001 comparing severely food insecure to food secure), but not men (OR 1.15, 95% CI 0.84-1.57, p = 0.3818 and OR 1.22, 95% CI 0.71-2.10, p = 0.4815). At the area-level, material deprivation was significantly associated with increased future risk comparing the most to the least deprived (OR females 2.39, 95% CI 1.77-3.23; OR males 1.61, 95% CI 1.22-2.14). Additionally, a strong protective effect was observed for women living in ethnically dense areas (OR 0.75, 95% CI 0.63-0.89, p = 0.0011) which was not as pronounced for men (OR 0.95, 95% CI 0.76-1.18, p = 0.6351). CONCLUSIONS: This study characterized socio-contextual predictors for future diabetes risk, showing sex-specific effects. Diabetes prevention must consider factors beyond individual-level behavioral lifestyle change and actively take steps to mitigate the adverse impacts of socio-contextual factors.

Frequency and Risk of Marijuana Use among Substance-Using Health Care Patients in Colorado with and without Access to State Legalized Medical Marijuana.

With increasing use of state legalized medical marijuana across the country, health care providers need accurate information on patterns of marijuana and other substance use for patients with access to medical marijuana. This study compared frequency and severity of marijuana use, and use of other substances, for patients with and without state legal access to medical marijuana. Data were collected from 2,030 patients who screened positive for marijuana use when seeking health care services in a large, urban safety-net medical center. Patients were screened as part of a federally funded screening, brief intervention, and referral to treatment (SBIRT) initiative. Patients were asked at screening whether they had a state-issued medical marijuana card and about risky use of tobacco, alcohol, and other illicit substances. A total of 17.4% of marijuana users had a medical marijuana card. Patients with cards had higher frequency of marijuana use and were more likely to screen at moderate than low or high risk from marijuana use. Patients with cards also had lower use of other substances than patients without cards. Findings can inform health care providers of both the specific risks of frequent, long-term use and the more limited risks of other substance use faced by legal medical marijuana users.

Binge drinking as a risk factor for violence among secondary school students in a nationally representative sample in Puerto Rico.

OBJECTIVE: The objective of this study was to determine the association between binge drinking and violence in a representative sample of secondary-school students in Puerto Rico. METHODS: Consulta Juvenil VII (a biennial survey of school-aged youths in Puerto Rico) has a representative sample of adolescent students in Puerto Rico. A multi-stage stratified cluster sampling design was used. The sampling frame of Consulta Juvenil VII includes all the public and private schools registered with the Department of Education and the Council of General Education in Puerto Rico. The study utilizes a self-administered questionnaire that was translated and adapted from the "Student Survey of Risk and Protective Factors and Prevalence of Alcohol, Tobacco, and Other Drug Use". "Binge drinking" was defined as having 5 or more alcoholic drinks in a row during the 30 days preceding the survey. RESULTS: Almost 20% of the sample members reported that at least 1 instance of binge drinking had taken place during the 2 weeks prior to the survey (17.7%). After controlling for gender, age, school level, the type of system, and the parents' educational levels, the odds of a given binge drinker reporting violent behaviors were 5 times greater than the odds among non-binge drinkers (OR: 5.6; 95% CI: 4.7-6.7). CONCLUSION: The study shows an association between binge drinking and violence in Puerto Rican adolescents, indicating that Hispanic youths who abuse alcohol may be at increased risk of violence. These findings suggest that violence prevention programs should be integrated with substance use prevention programs. [PR Health

Peptidomic study of Spanish blue cheese (Valdeón) and changes after simulated gastrointestinal digestion.

It is increasingly evident that digestion can affect the biological activity of cheese by the release of new active peptides from their precursors or, on the contrary, giving rise to fragments without activity. The characterization of the peptidome of a Spanish blue cheese, Valdeón, has been conducted before and after gastrointestinal digestion, and the digests have been compared to those obtained from pasteurized skimmed milk powder (SMP) using a bioinformatics platform. Peptidomic profiling of digests revealed several regions that are especially resistant to digestion (among them ß-casein 60-93, 128-140, and 193-209). Some of them correspond to well-conserved regions between species (human, cow, sheep, and goat) and include peptide sequences with reported bioactivity. The great peptide homology found between both digests, cheese and SMP, suggests that the gastrointestinal digestion could bring closer the profile of products with different proteolytic state. Although most of the biologically active peptides found in cheese after digestion were also present in SMP digest, there were some exceptions that can be attributed to the absence of the relevant precursor peptide before digestion.

Phthalocyanine tetrasulfonates bind to multiple sites on natively-folded prion protein.

The phthalocyanine tetrasulfonates (PcTS), a class of cyclic tetrapyrroles, bind to the mammalian prion protein, PrP. Remarkably, they can act as anti-scrapie agents to prevent the formation and spread of infectious, misfolded PrP. While the effects of phthalocyanines on the diseased state have been investigated, the interaction between PcTS and PrP has not yet been extensively characterized. Here we use multiple, complementary assays (surface plasmon resonance, isothermal titration calorimetry, fluorescence correlation spectroscopy, and tryptophan fluorescence quenching) to characterize the binding of PcTS to natively-folded hamster PrP(90-232), in order to determine binding constants, ligand stoichiometry, influence of buffer ionic strength, and the effects of chelated metal ions. We found that binding strength depends strongly on chelated metal ions, with Al(3+)-PcTS binding the weakest and free-base PcTS the strongest of the three types tested (Al(3+), Zn(2+), and free-base). Buffer ionic strength also affected the binding, with K(d) increasing along with salt concentration. The binding isotherms indicated the presence of at least two different binding sites with micromolar affinities and a total stoichiometry of ~4-5 PcTS molecules per PrP molecule.

Hemlock woolly adelgid (Adelges tsugae) infestation affects water and carbon relations of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana).

Hemlock woolly adelgid (HWA) is an exotic insect pest causing severe decimation of native hemlock trees. Extensive research has been conducted on the ecological impacts of HWA, but the exact physiological mechanisms that cause mortality are not known. Water relations, anatomy and gas exchange measurements were assessed on healthy and infested eastern (Tsuga canadensis) and Carolina (Tsuga caroliniana) hemlock trees. These data were then used in a mechanistic model to test whether the physiological responses to HWA infestation were sufficiently significant to induce changes in whole-plant water use and carbon uptake. The results indicated coordinated responses of functional traits governing water relations in infested relative to healthy trees. In response to HWA, leaf water potential, carbon isotope ratios, plant hydraulic properties and stomatal conductance were affected, inducing a reduction in tree water use by > 40% and gross primary productivity by 25%. Anatomical changes also appeared, including the activation of traumatic cells. HWA infestation had a direct effect on plant water relations. Despite some leaf compensatory mechanisms, such as an increase in leaf hydraulic conductance and nitrogen content, tree water use and carbon assimilation were diminished significantly in infested trees, which could contribute to tree mortality.