Glycolysis: An early marker for vancomycin-specific T-cell activation.

BACKGROUND: Vancomycin, a glycopeptide antibiotic used for Gram-positive bacterial infections, has been linked with drug reaction with eosinophilia and systemic symptoms (DRESS) in HLA-A*32:01-expressing individuals. This is associated with activation of T lymphocytes, for which glycolysis has been isolated as a fuel pathway following antigenic stimulation. However, the metabolic processes that underpin drug-reactive T-cell activation are currently undefined and may shed light on the energetic conditions needed for the elicitation of drug hypersensitivity or tolerogenic pathways. Here, we sought to characterise the immunological and metabolic pathways involved in drug-specific T-cell activation within the context of DRESS pathogenesis using vancomycin as model compound and drug-reactive T-cell clones (TCCs) generated from healthy donors and vancomycin-hypersensitive patients. METHODS: CD4+ and CD8+ vancomycin-responsive TCCs were generated by serial dilution. The Seahorse XFe96 Analyzer was used to measure the extracellular acidification rate (ECAR) as an indicator of glycolytic function. Additionally, T-cell proliferation and cytokine release (IFN-γ) assay were utilised to correlate the bioenergetic characteristics of T-cell activation with in vitro assays. RESULTS: Model T-cell stimulants induced non-specific T-cell activation, characterised by immediate augmentation of ECAR and rate of ATP production (JATPglyc). There was a dose-dependent and drug-specific glycolytic shift when vancomycin-reactive TCCs were exposed to the drug. Vancomycin-reactive TCCs did not exhibit T-cell cross-reactivity with structurally similar compounds within proliferative and cytokine readouts. However, cross-reactivity was observed when analysing energetic responses; TCCs with prior specificity for vancomycin were also found to exhibit glycolytic switching after exposure to teicoplanin. Glycolytic activation of TCC was HLA restricted, as exposure to HLA blockade attenuated the glycolytic induction. CONCLUSION: These studies describe the glycolytic shift of CD4+ and CD8+ T cells following vancomycin exposure. Since similar glycolytic switching is observed with teicoplanin, which did not activate T cells, it is possible the master switch for T-cell activation is located upstream of metabolic signalling.

Production and transport of plasma-generated hydrogen peroxide from gas to liquid.

In this work, the transport of hydroxyl radicals and hydrogen peroxide from a humid atmospheric pressure plasma jet into plasma-treated liquids is analysed. The concentration of H2O2 was measured by a spectrophotometric approach using the reagent ammonium metavanadate. OH was measured by the terephthalic acid dosimeter and the chemiluminescence of luminol. The plasma jet used is based on the design of the well-investigated COST reference jet and is extended by a capillary between the two electrodes. In addition to the experiments, the 0-dimensional plasma-chemical kinetics code GlobalKin was used to analyse the plasma chemistry in the gas phase in more detail. After 5 min plasma treatment, a maximum H2O2 concentration of 1 mM was found in the liquid, while the OH concentration was a factor 50 lower. The concentrations of both species in the liquid increased with plasma power, and the H2O2 concentration also increased with the humidity concentration of the feed gas, while the OH concentration first increased with humidity admixture and then decreased. The transport of both species could be controlled by the treatment distance, the gas flow rate and low frequency pulsing of the RF jet in such a way that the selectivity towards the long-lived species H2O2 was increased. Qualitative trends in the simulated number densities of gas phase H2O2 and OH at the location of the gas-liquid interface fit relatively well to the experimental measurements in the liquid.

Using data-driven approaches to improve delivery of animal health care interventions for public health.

Rabies kills ∼60,000 people per year. Annual vaccination of at least 70% of dogs has been shown to eliminate rabies in both human and canine populations. However, delivery of large-scale mass dog vaccination campaigns remains a challenge in many rabies-endemic countries. In sub-Saharan Africa, where the vast majority of dogs are owned, mass vaccination campaigns have typically depended on a combination of static point (SP) and door-to-door (D2D) approaches since SP-only campaigns often fail to achieve 70% vaccination coverage. However, D2D approaches are expensive, labor-intensive, and logistically challenging, raising the need to develop approaches that increase attendance at SPs. Here, we report a real-time, data-driven approach to improve efficiency of an urban dog vaccination campaign. Historically, we vaccinated ∼35,000 dogs in Blantyre city, Malawi, every year over a 20-d period each year using combined fixed SP (FSP) and D2D approaches. To enhance cost effectiveness, we used our historical vaccination dataset to define the barriers to FSP attendance. Guided by these insights, we redesigned our vaccination campaign by increasing the number of FSPs and eliminating the expensive and labor-intensive D2D component. Combined with roaming SPs, whose locations were defined through the real-time analysis of vaccination coverage data, this approach resulted in the vaccination of near-identical numbers of dogs in only 11 d. This approach has the potential to act as a template for successful and sustainable future urban SP-only dog vaccination campaigns.

Data-driven acoustic control of a spherical bubble using a Koopman linear quadratic regulator.

Koopman operator theory has gained interest as a framework for transforming nonlinear dynamics on the state space into linear dynamics on abstract function spaces, which preserves the underlying nonlinear dynamics of the system. These spaces can be approximated through data-driven methodologies, which enables the application of classical linear control strategies to nonlinear systems. Here, a Koopman linear quadratic regulator (KLQR) was used to acoustically control the nonlinear dynamics of a single spherical bubble, as described by the well-known Rayleigh-Plesset equation, with several objectives: (1) simple harmonic oscillation at amplitudes large enough to incite nonlinearities, (2) stabilization of the bubble at a nonequilibrium radius, and (3) periodic and quasiperiodic oscillation with multiple frequency components of arbitrary amplitude. The results demonstrate that the KLQR controller can effectively drive a spherical bubble to radially oscillate according to prescribed trajectories using both broadband and single-frequency acoustic driving. This approach has several advantages over previous efforts to acoustically control bubbles, including the ability to track arbitrary trajectories, robustness, and the use of linear control methods, which do not depend on initial guesses.

Updates on the immunopathology and genomics of severe cutaneous adverse drug reactions.

Severe cutaneous adverse reactions (SCARs) such as Stevens-Johnson syndrome, toxic epidermal necrolysis (SJS/TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS) cause significant morbidity and mortality and impede new drug development. HLA class I associations with SJS/TEN and drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome have aided preventive efforts and provided insights into immunopathogenesis. In SJS/TEN, HLA class I-restricted oligoclonal CD8+ T-cell responses occur at the tissue level. However, specific HLA risk allele(s) and antigens driving this response have not been identified for most drugs. HLA risk alleles also have incomplete positive and negative predictive values, making truly comprehensive screening currently challenging. Although, there have been key paradigm shifts in knowledge regarding drug hypersensitivity, there are still many open and unanswered questions about SCAR immunopathogenesis, as well as genetic and environmental risk. In addition to understanding the cellular and molecular basis of SCAR at the single-cell level, identification of the MHC-restricted drug-reactive self- or viral peptides driving the hypersensitivity reaction will also be critical to advancing premarketing strategies to predict risk at an individual and drug level. This will also enable identification of biologic markers for earlier diagnosis and accurate prognosis, as well as drug causality and targeted therapeutics.

Chronic anti-coagulation therapy reduced mortality in patients with high cardiovascular risk early in COVID-19 pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with provoked thrombo-inflammatory responses. Early in the COVID-19 pandemic this was thought to contribute to hypercoagulability and multi-organ system complications in infected patients. Limited studies have evaluated the impact of therapeutic anti-coagulation therapy (AC) in alleviating these risks in COVID-19 positive patients. Our study aimed to investigate whether long-term therapeutic AC can decrease the risk of multi-organ system complications (MOSC) including stroke, limb ischemia, gastrointestinal (GI) bleeding, in-hospital and intensive care unit death in COVID-19 positive patients hospitalized during the early phase of the pandemic in the United States. METHODS: A retrospective analysis was conducted of all COVID-19 positive United States Veterans between March 2020 and October 2020. Patients receiving continuous outpatient therapeutic AC for a least 90 days prior to their initial COVID-19 positive test were assigned to the AC group. Patients who did not receive AC were included in a control group. We analyzed the primary study outcome of MOSC between the AC and control groups using binary logistic regression analysis (Odd-Ratio; OR). RESULTS: We identified 48,066 COVID-19 patients, of them 879 (1.8%) were receiving continuous therapeutic AC. The AC cohort had significantly worse comorbidities than the control group. On the adjusted binary logistic regression model, therapeutic AC significantly decreased in-hospital mortality rate (OR; 0.67, p = 0.04), despite a higher incidence of GI bleeding (OR; 4.00, p = 0.02). However, therapeutic AC did not significantly reduce other adverse events. CONCLUSION: AC therapy reduced in-hospital death early in the COVID-19 pandemic among patients who were hospitalized with the infection. However, it did not decrease the risk of MOSC. Additional trials are needed to determine the effectiveness of AC in preventing complications associated with ongoing emerging strains of the COVID-19 virus.

Combined central serous chorioretinopathy, hypermetropia, short axial length, chorioretinal folds, enlarged/thickened ocular coats, with varying association of scleral changes (CHAFES).

PURPOSE: To describe a condition with the following features: chronic central serous chorioretinopathy (CCSC), chorioretinal folds, scleral changes (including any of the following flattened or 'squared off' posterior pole, 'T sign', or thickened ocular coats), accompanied by a short axial length and hypermetropia in a series of 7 patients. METHODS: The case notes of 7 patients presenting with a combination of CSC, choroidal folds scleral changes and hypermetropia were reviewed as part of a retrospective case series. Corrected visual acuities, serial refraction, colour imaging, fluorescein and indocyanine green angiography findings, together with B-ultrasound scan features were recorded, with axial length measurements as available (< 23.3 mm was defined as short). RESULTS: The study included 14 eyes of 7 subjects (2 females and 5 males) with a primary presentation of central vision disturbance. All patients showed signs of previous or current episodes of the following features in at least one eye: CSC (5/7 bilateral); choroidal folds (6/7 bilateral), thickening of ocular coats in the 5 in whom this was measured, at least one scleral abnormality on ultrasound in at least one eye. A short axial length at final appointment was recorded in 13/14 eyes. CONCLUSIONS AND RELEVANCE: The combination of CCSC with choroidal folds, hypermetropia with apparent shortening of the eyeball associated with one or more scleral abnormalities such as a flattened or 'squared off 'appearance of the B ultrasound may be a specific ocular condition. The aetiology of this particular combination of posterior segment manifestations is unknown; the choroid could be the primary focus of disease with secondary involvement of the sclera. Alternatively, the features observed may result from a chronic inflammatory process affecting the sclera with secondary effects on the choroid, retinal pigment epithelium and retina. In our case series, the final vision was not significantly different from vision at presentation.

Evaluating the benefit of early patient and public involvement for product development and testing with small companies.

INTRODUCTION: There is a growing understanding of the benefits of patient and public involvement (PPI), and its evaluation, in research. An online version of the CUBE PPI evaluation framework has been developed. We sought to use the CUBE to evaluate the value of early PPI with two small healthcare companies during product development. METHODS: Contributors were recruited online and had lived experience of either type 1 diabetes or obesity. Two 1-h sessions were run with a company developing a smartphone application to manage diabetes (DEE-EM): one with young people (YP; n = 5) and one with parents (n = 7). Two 1-h sessions were run with a company developing a weight-loss product, both with adults (n = 7 in each session). Sessions were facilitated by an independent University researcher and attended by company representatives, who presented their product. One facilitator led the evaluation of the session by giving a demonstration of the CUBE and asking simple questions in the YP session. RESULTS: A high proportion of contributors completed the CUBE (80.5% DEE-EM; 93% Oxford Medical Products). Responses were positive to all four CUBE dimensions (in italics). Contributors felt there were diverse ways to contribute to the sessions, and that they had a strong voice to add to the discussion. Balance was achieved regarding whose concerns (public or company) led the agenda, and contributors felt that both companies would make changes based on the discussion. The supportive attitude of both companies resulted in most contributors feeling comfortable participating in PPI sessions with the industry, while recognising the profit-making aspect of their work. CONCLUSIONS: PPI with small healthcare companies is both feasible and worthwhile. The CUBE framework facilitated the evaluation of the interaction between experts in different knowledge spaces. We provide recommendations for future projects, including considerations of who should participate and the level of implicit endorsement of the product that participation implies. PATIENT OR PUBLIC CONTRIBUTION: People with lived experience of type 1 diabetes or obesity were invited to contribute to one of four PPI sessions, which they then evaluated. One contributor agreed to contribute to the analysis of the evaluation data and interpretation and preparation of the manuscript.

Skewed allelic expression on X chromosome associated with aberrant expression of XIST on systemic lupus erythematosus lymphocytes.

A common feature of autoimmune diseases, including systemic lupus erythematosus (SLE), is an increased prevalence in women. However, the molecular basis for sex disparity in SLE remains poorly understood. To examine the role of X-linked transcription in SLE adaptive immune cells, we performed RNA-seq in T cell and B cell subsets from either healthy donors or patients with SLE. Analyses of allelic expression (AE) profiles identified a pattern of increased allelic imbalance across the entire X chromosome in SLE lymphocytes. X-linked genes exhibiting AE in SLE had an extensive overlap with genes known to escape X chromosome inactivation (XCI). XIST RNA was overexpressed in SLE patients. Differential XIST expression correlated with AE profiles more positively at X-linked genes than the genome-wide background. Analysis of three independent RNA-seq data verified the XIST-associated skewed AE on X chromosome in SLE. Integrative analyses of DNA methylation profiles showed an increased variability of DNA methylation levels at these AE-related X-linked genes. In cultured lymphoblastic cells, knockdown of XIST specifically altered allelic imbalance patterns between X chromosomes. Our study provides genetic evidence that upregulation of XIST accompanied with more skewed allelic expression on X chromosome is associated with the pathogenesis of SLE and may provide mechanistic insights into the increased incidence of SLE in females.

HLA-B*07:02 and HLA-C*07:02 are associated with trimethoprim-sulfamethoxazole respiratory failure.

We have identified an underrecognized severe adverse drug reaction (ADR) of trimethoprim-sulfamethoxazole (TMP-SMX) associated respiratory failure in previously healthy children and young adults. We investigated potential genetic risk factors associated with TMP-SMX induced respiratory failure in a cohort of seven patients. We explored whole genome sequence among seven patients representing nearly half of all reported cases worldwide and 63 unrelated control individuals in two stages: (1) human leukocyte antigen (HLA) locus variation as several other ADRs have been associated HLA genetic variants and (2) coding variation to catalog and explore potential rare variants contributing to this devastating reaction. All cases were either heterozygous (carriers) or homozygous for the common HLA-B*07:02-HLA-C*07:02 haplotype. Despite the small sample size, this observation is statistically significant both in conservative comparison to maximum reported population frequencies (binomial P = 0.00017 for HLA-B and P = 0.00028 for HLA-C) and to our control population assessed by same HLA genotyping approach (binomial P = 0.000001 for HLA-B and P = 0.000018 for HLA-C). No gene elsewhere in the genome harnessed shared rare case enriched coding variation. Our results suggests that HLA-B*07:02 and HLA-C*07:02 are necessary for a patient to develop respiratory failure due to TMP-SMX.

Impact of Socioeconomic Status on Major Amputation in Patients with Peripheral Vascular Disease and Diabetes Mellitus.

BACKGROUND: Both peripheral vascular disease (PVD) and diabetes mellitus (DM) are leading causes of lower extremity amputation. The Area Deprivation Index (ADI) is a tool used to estimate socioeconomic status (SES) based off a person's 9-digit zip code, and this value has been shown to correlate with poor health outcomes. We sought to understand the effect of SES on major amputation in diabetic patients with PVD in a single healthcare system. METHODS: All patients presenting to a single healthcare system with dual diagnosis of PVD and DM from January 2012 to December 2017 were identified using International Classification of Diseases (ICD) 9/10 codes. Patients undergoing major amputation (below-knee and above-knee) were identified by Current Procedural Terminology (CPT) codes and compared to those who did not have amputation. The ADI score and comorbid disease processes were identified. The Mann-Whitney U-test was performed to compare ADI scores between the amputation and nonamputation groups. Categorical variables were analyzed using the Chi-squared or Fisher's exact test, and t-tests were used for continuous variables. A logistic regression was performed to test the association between SES and amputation status. RESULTS: A total of 2,009 patients were identified, of which 85 underwent major amputation. After adjusting for comorbidities, patients in the amputation group had higher ADI scores as compared to those who did not have amputation (median ADI score 8 vs. 6, P < 0.05). Logistic regression modeling demonstrated an Odds Ratio of 1.10 (95% confidence interval: 1.01-1.19), indicating the odds of being in the amputation group are increased by 10% for every 1-point increase in the ADI score. CONCLUSIONS: After controlling for comorbidities, patients with PVD and DM residing in neighborhoods with lower SES have increased odds of undergoing major lower-limb amputation than those from neighborhoods with higher SES despite receiving care at the same healthcare system. Further study is warranted to determine factors contributing to this difference.

The role of IL-6 and other mediators in the cytokine storm associated with SARS-CoV-2 infection.

The coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome coronavirus 2 presents with a spectrum of clinical manifestations from asymptomatic or mild, self-limited constitutional symptoms to a hyperinflammatory state ("cytokine storm") followed by acute respiratory distress syndrome and death. The objective of this study was to provide an evidence-based review of the associated pathways and potential treatment of the hyperinflammatory state associated with severe acute respiratory syndrome coronavirus 2 infection. Dysregulated immune responses have been reported to occur in a smaller subset of those infected with severe acute respiratory syndrome coronavirus 2, leading to clinical deterioration 7 to 10 days after initial presentation. A hyperinflammatory state referred to as cytokine storm in its severest form has been marked by elevation of IL-6, IL-10, TNF-α, and other cytokines and severe CD4+ and CD8+ T-cell lymphopenia and coagulopathy. Recognition of at-risk patients could permit early institution of aggressive intensive care and antiviral and immune treatment to reduce the complications related to this proinflammatory state. Several reports and ongoing clinical trials provide hope that available immunomodulatory therapies could have therapeutic potential in these severe cases. This review highlights our current state of knowledge of immune mechanisms and targeted immunomodulatory treatment options for the current coronavirus disease 2019 pandemic.

Immune dysregulation increases the incidence of delayed-type drug hypersensitivity reactions.

Delayed-type, T cell-mediated, drug hypersensitivity reactions are a serious unwanted manifestation of drug exposure that develops in a small percentage of the human population. Drugs and drug metabolites are known to interact directly and indirectly (through irreversible protein binding and processing to the derived adducts) with HLA proteins that present the drug-peptide complex to T cells. Multiple forms of drug hypersensitivity are strongly linked to expression of a single HLA allele, and there is increasing evidence that drugs and peptides interact selectively with the protein encoded by the HLA allele. Despite this, many individuals expressing HLA risk alleles do not develop hypersensitivity when exposed to culprit drugs suggesting a nonlinear, multifactorial relationship in which HLA risk alleles are one factor. This has prompted a search for additional susceptibility factors. Herein, we argue that immune regulatory pathways are one key determinant of susceptibility. As expression and activity of these pathways are influenced by disease, environmental and patient factors, it is currently impossible to predict whether drug exposure will result in a health benefit, hypersensitivity or both. Thus, a concerted effort is required to investigate how immune dysregulation influences susceptibility towards drug hypersensitivity.

Tolvaptan- and Tolvaptan-Metabolite-Responsive T Cells in Patients with Drug-Induced Liver Injury.

Tolvaptan is an effective drug for the treatment of autosomal dominant polycystic kidney disease, but its use is associated with a significant risk of liver injury in a small number of patients. Herein we describe the presence of tolvaptan- and tolvaptan-metabolite-responsive T cell clones within the peripheral circulation of patients with liver injury. Drug treatment of the clones resulted in a proliferative response and secretion of IFN-γ, IL-13, and the cytolytic molecule granzyme B. Future work should explore pathways of tolvaptan driven T cell activation and the role of T cells in the disease pathogenesis.

Evolving insights into the mechanisms of toxicity associated with immune checkpoint inhibitor therapy.

Immune checkpoint inhibitors have emerged as a revolutionary treatment option for patients with various types of malignancy. Although these agents afford a significant improvement in outcomes for melanoma and other previously untreatable malignancies, their novel mechanism of action may predispose patients to immune-related adverse effects (irAEs). In the tumour neoantigen environment, these irAEs are due to the activation of the immune system by the blockade of suppressive checkpoints, leading to increases in T-cell activation and proliferation. IrAEs have been reported in almost any organ and at any point in time, even months to years after discontinuation of therapy. Certain populations with distinct physiological changes, genetic risk factors, and specific antigen exposures may be more highly predisposed to develop irAEs. This review discusses the incidence and mechanisms of irAEs and the relationship between host factors and irAE occurrence.

Dapsone- and nitroso dapsone-specific activation of T cells from hypersensitive patients expressing the risk allele HLA-B*13:01.

BACKGROUND: Research into drug hypersensitivity associated with the expression of specific HLA alleles has focussed on the interaction between parent drug and the HLA with no attention given to reactive metabolites. For this reason, we have studied HLA-B*13:01-linked dapsone hypersensitivity to (a) explore whether the parent drug and/or nitroso metabolite activate T cells and (b) determine whether HLA-B*13:01 is involved in the response. METHODS: Peripheral blood mononuclear cells (PBMC) from six patients were cultured with dapsone and nitroso dapsone, and proliferative responses and IFN-γ release were measured. Dapsone- and nitroso dapsone-specific T-cell clones were generated and phenotype, function, HLA allele restriction, and cross-reactivity assessed. Dapsone intermediates were characterized by mass spectrometry. RESULTS: Peripheral blood mononuclear cells from six patients and cloned T cells proliferated and secreted Th1/2/22 cytokines when stimulated with dapsone (clones: n = 395; 80% CD4+ CXCR3hi CCR4hi , 20% CD8+CXCR3hi CCR4hi CCR6hi CCR9hi CCR10hi ) and nitroso dapsone (clones: n = 399; 78% CD4+, 22% CD8+ with same chemokine receptor profile). CD4+ and CD8+ clones were HLA class II and class I restricted, respectively, and displayed three patterns of reactivity: compound specific, weakly cross-reactive, and strongly cross-reactive. Nitroso dapsone formed dimers in culture and was reduced to dapsone, providing a rationale for the cross-reactivity. T-cell responses to nitroso dapsone were dependent on the formation of a cysteine-modified protein adduct, while dapsone interacted in a labile manner with antigen-presenting cells. CD8+ clones displayed an HLA-B*13:01-restricted pattern of activation. CONCLUSION: These studies describe the phenotype and function of dapsone- and nitroso dapsone-responsive CD4+ and CD8+ T cells from hypersensitive patients. Discovery of HLA-B*13:01-restricted CD8+ T-cell responses indicates that drugs and their reactive metabolites participate in HLA allele-linked forms of hypersensitivity.

Impaired behavioural flexibility related to white matter microgliosis in the TgAPP21 rat model of Alzheimer disease.

Executive dysfunction and white matter inflammation continue to be relatively understudied in rodent models of Alzheimer's disease (AD). Behavioural inflexibility is an important component of executive dysfunction that can be further categorized as perseverative or regressive, which respectively specify whether maladaptive persistence occurs early or late during a behavioural change. Previous studies of the TgAPP21 rat model of AD (expressing pathogenic hAPP) suggested a potentially spontaneous increase of regressive behavioral inflexibility. In this study, 7-8-month-old male TgAPP21 rats were tested for behavioral flexibility, learning, and memory using an operant conditioning chamber and the Morris Water Maze (MWM). TgAPP21 rats demonstrated a regressive behavioral inflexibility during set shifting in an operant conditioning chamber (regressive errors η2 = 0.32 and number of errors after criterion η2 = 0.33). Regressive behavior was also demonstrated in the MWM probe test, wherein TgAPP21 rats significantly increased their swim time in the target quadrant during the last third of the probe test (43% vs 33% in the first 2 thirds of the probe test or the Wt rats' 29%-32%); this behavioral phenotype has not been previously described in the MWM. TgAPP21 demonstrated further impairment of behavioural inflexibility as they committed a greater number of reversal errors in the operant conditioning chamber (η2 = 0.30). Diffuse microglia activation was increased in the white matter tracts of TgAPP21 (corpus callosum, cingulum, and internal capsule; η2 = 0.59-0.62), which was found to correlate with the number of reversal errors in the operant conditioning chamber (R2 = 0.42). As TgAPP21 rats do not spontaneously develop amyloid plaques but have been shown in previous studies to be vulnerable to the development of plaques, these rats demonstrate an important onset of cognitive change and inflammation in the pre-plaque phase of AD. TgAPP21 rats are also an instrumental model for studying the role and mechanism of white matter microglial activation in executive functioning. This is pertinent to clinical research of prodromal AD which has suggested that white matter inflammation may underlie impairment of executive functions such as behavioral flexibility.

Development of a high number, high coverage dog rabies vaccination programme in Sri Lanka.

BACKGROUND: Rabies is estimated to cause 59,000 deaths and economic losses of US$8.6 billion every year. Despite several years of rabies surveillance and awareness programmes, increased availability of post-exposure prophylaxis vaccinations and dog population control, the disease still remains prevalent in Sri Lanka. This study reports the roll-out of a high number, high coverage canine rabies vaccination campaign in Sri Lanka, providing estimates for the vaccination coverage achieved, analysing the local dog demographics, and identifying barriers of attendance to static vaccination clinics. METHODS: A mass dog vaccination campaign was undertaken in Negombo, Sri Lanka. The campaign was composed of static point and door-to-door vaccination stages, with a final survey of vaccination coverage. A large volume of data on the distribution, health, and signalment of vaccinated dogs was collected through a mobile phone application. A logistic regression model was developed to investigate which socio-spatial and dog-related factors influenced attendance of owners to static vaccination points. RESULTS: The campaign vaccinated over 7800 dogs achieving a vaccination coverage of 75.8%. A dog:human ratio of 1:17 was estimated. Most dogs were owned, and the dog population was mostly male, adult, and non-sterilized. Unawareness, unavailability and handling problems were the most common reasons given by owners to explain failure to attend a static vaccination point. The regression analysis showed that increasing distance to a static point, in addition to young age and poor health of the dog, were associated with a decrease in the likelihood of attendance to a static vaccination points. CONCLUSION: This study demonstrates the feasibility of high number, high coverage vaccination campaigns in Sri Lanka. The information on dog ecology and barriers of attendance to static point vaccination clinics will facilitate development of future vaccination campaigns.

The Effect of Inhibitory Signals on the Priming of Drug Hapten-Specific T Cells That Express Distinct Vß Receptors.

Drug hypersensitivity involves the activation of T cells in an HLA allele-restricted manner. Because the majority of individuals who carry HLA risk alleles do not develop hypersensitivity, other parameters must control development of the drug-specific T cell response. Thus, we have used a T cell-priming assay and nitroso sulfamethoxazole (SMX-NO) as a model Ag to investigate the activation of specific TCR Vß subtypes, the impact of programmed death -1 (PD-1), CTL-associated protein 4 (CTLA4), and T cell Ig and mucin domain protein-3 (TIM-3) coinhibitory signaling on activation of naive and memory T cells, and the ability of regulatory T cells (Tregs) to prevent responses. An expansion of the TCR repertoire was observed for nine Vß subtypes, whereas spectratyping revealed that SMX-NO-specific T cell responses are controlled by public TCRs present in all individuals alongside private TCR repertoires specific to each individual. We proceeded to evaluate the extent to which the activation of these TCR Vß-restricted Ag-specific T cell responses is governed by regulatory signals. Blockade of PD-L1/CTLA4 signaling dampened activation of SMX-NO-specific naive and memory T cells, whereas blockade of TIM-3 produced no effect. Programmed death-1, CTLA4, and TIM-3 displayed discrete expression profiles during drug-induced T cell activation, and expression of each receptor was enhanced on dividing T cells. Because these receptors are also expressed on Tregs, Treg-mediated suppression of SMX-NO-induced T cell activation was investigated. Tregs significantly dampened the priming of T cells. In conclusion, our findings demonstrate that distinct TCR Vß subtypes, dysregulation of coinhibitory signaling pathways, and dysfunctional Tregs may influence predisposition to hypersensitivity.

In situ XPS analysis of the atomic layer deposition of aluminium oxide on titanium dioxide.

Ultra-thin aluminium oxide was grown on a rutile titanium dioxide surface by atomic layer deposition using trimethylaluminium and water precursors. This process, carried out using realistic temperatures and pressures (1 mbar, 450 K), was monitored in situ using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS). This provides insight into the surface chemistry at the interface between the two oxide layers - specifically the reduction of titanium atoms from Ti4+ to Ti3+ upon dosing of trimethylaluminium. These defect states become locked into the heterojunction's interface, with implications to its electronic structure, and can act as an indicator as to when complete coverage of the rutile substrate is achieved.