Activation of Human CD8+ T Cells with Nitroso Dapsone-Modified HLA-B*13:01-Binding Peptides

Previous studies have shown that cysteine-reactive drug metabolites bind covalently with protein to activate patient T cells. However, the nature of the antigenic determinants that interact with HLA and whether T cell stimulatory peptides contain the bound drug metabolite has not been defined. Because susceptibility to dapsone hypersensitivity is associated with the expression of HLA-B*13:01, we have designed and synthesized nitroso dapsone-modified, HLA-B*13:01 binding peptides and explored their immunogenicity using T cells from hypersensitive human patients. Cysteine-containing 9-mer peptides with high binding affinity to HLA-B*13:01 were designed (AQDCEAAAL [Pep1], AQDACEAAL [Pep2], and AQDAEACAL [Pep3]), and the cysteine residue was modified with nitroso dapsone. CD8+ T cell clones were generated and characterized in terms of phenotype, function, and cross-reactivity. Autologous APCs and C1R cells expressing HLA-B*13:01 were used to determine HLA restriction. Mass spectrometry confirmed that nitroso dapsone-peptides were modified at the appropriate site and were free of soluble dapsone and nitroso dapsone. APC HLA-B*13:01-restricted nitroso dapsone-modified Pep1- (n = 124) and Pep3-responsive (n = 48) CD8+ clones were generated. Clones proliferated and secreted effector molecules with graded concentrations of nitroso dapsone-modified Pep1 or Pep3. They also displayed reactivity against soluble nitroso dapsone, which forms adducts in situ, but not with the unmodified peptide or dapsone. Cross-reactivity was observed between nitroso dapsone-modified peptides with cysteine residues in different positions in the peptide sequence. These data characterize a drug metabolite hapten CD8+ T cell response in an HLA risk allele-restricted form of drug hypersensitivity and provide a framework for structural analysis of hapten HLA binding interactions.

Evaluation of wind power generation projects to reduce air pollution using multi-criteria decision-making methods in Saudi Arabia

Currently, Saudi Arabia has very limited renewable energy generation capacity, as most of the country's electricity sector is dependent on cheap fossil fuels. However, in recent years, the Saudi government has announced a national development program called "the Saudi Vision 2030," whereby the country intends to increase the share of renewable energies in its total power generation to 20% by 2030. This research is aimed on the possibility of developing wind farms in Saudi Arabia's Al-Jawf area, which is known to be rich in wind sources. The potential of wind energy in the region was examined in the first phase of the research, which focused at the environmental, economic, and technical aspects. For this goal, the two-parameter Weibull function was used to model wind energy in the area. The economic assessment was performed in terms of the Levelized Cost of Energy and payback period. Multi-criteria decision-making approaches were employed in the second phase of the study to determine the most proper sites for harvesting wind energy in the study region based on eight factors including technical, economic, environmental, and social aspects. The most proper site for wind farms was identified by the combined use of Stepwise Weight Assessment Ratio Analysis and Weighted Aggregated Sum Product Assessment. The results showed that the most proper site for locating wind farms in the study area is the city of Al-Qurrayyat, where, using 1 MW turbines, it will be possible to produce 2357 MWh/year of electricity at a cost of 0.092 $/kWh, resulting in a payback period of 8.1 years. From the environmental perspective, wind power generation in Al-Qurrayyat will result in 1124.15 ton/year of CO₂ emissions reduction.

Transformational leadership and project success: The mediating role of trust and job satisfaction

Transformational leadership (TFL) impacts on project and organizational success are well established. However, many underlying factors that make TFL effective are still missing. Therefore, we formulated hypotheses and tested the mediating role of trust (TS) and job satisfaction (JS) in linking TFL to project success (PS). A time-lagged methodology was used to collect quantitative data using a structured questionnaire from 326 project manager-team member dyads working in Pakistan’s public sector. Our results showed that TS, JS, and TFL significantly impacted project success. Moreover, we found that TS and JS mediate the relationship between TFL and PS. These findings highlight the importance of trust and job satisfaction as mechanisms that translate TFL into the success of projects for organizations.

Incorporating CNN Features for Optimizing Performance of Ensemble Classifier for Cardiovascular Disease Prediction

Cardiovascular diseases (CVDs) have been regarded as the leading cause of death with 32% of the total deaths around the world. Owing to the large number of symptoms related to age, gender, demographics, and ethnicity, diagnosing CVDs is a challenging and complex task. Furthermore, the lack of experienced staff and medical experts, and the non-availability of appropriate testing equipment put the lives of millions of people at risk, especially in under-developed and developing countries. Electronic health records (EHRs) have been utilized for diagnosing several diseases recently and show the potential for CVDs diagnosis as well. However, the accuracy and efficacy of EHRs-based CVD diagnosis are limited by the lack of an appropriate feature set. Often, the feature set is very small and unable to provide enough features for machine learning models to obtain a good fit. This study solves this problem by proposing the novel use of feature extraction from a convolutional neural network (CNN). An ensemble model is designed where a CNN model is used to enlarge the feature set to train linear models including stochastic gradient descent classifier, logistic regression, and support vector machine that comprise the soft-voting based ensemble model. Extensive experiments are performed to analyze the performance of different ratios of feature sets to the training dataset. Performance analysis is carried out using four different datasets and results are compared with recent approaches used for CVDs. Results show the superior performance of the proposed model with 0.93 accuracy, and 0.92 scores each for precision, recall, and F1 score. Results indicate both the superiority of the proposed approach, as well as the generalization of the ensemble model using multiple datasets.

Analyses of Public Attention and Sentiments towards Different COVID-19 Vaccines Using Data Mining Techniques

COVID-19 is a widely spread disease, and in order to overcome its spread, vaccination is necessary. Different vaccines are available in the market and people have different sentiments about different vaccines. This study aims to identify variations and explore temporal trends in the sentiments of tweets related to different COVID-19 vaccines (Covaxin, Moderna, Pfizer, and Sinopharm). We used the Valence Aware Dictionary and Sentiment Reasoner (VADER) tool to analyze the public sentiments related to each vaccine separately and identify whether the sentiments are positive (compound ≥ 0.05), negative (compound ≤ −0.05), or neutral (−0.05 < compound < 0.05). Then, we analyzed tweets related to each vaccine further to find the time trends and geographical distribution of sentiments in different regions. According to our data, overall sentiments about each vaccine are neutral. Covaxin is associated with 28% positive sentiments and Moderna with 37% positive sentiments. In the temporal analysis, we found that tweets related to each vaccine increased in different time frames. Pfizer- and Sinopharm-related tweets increased in August 2021, whereas tweets related to Covaxin increased in July 2021. Geographically, the highest sentiment score (0.9682) is for Covaxin from India, while Moderna has the highest sentiment score (0.9638) from the USA. Overall, this study shows that public sentiments about COVID-19 vaccines have changed over time and geographically. The sentiment analysis can give insights into time trends that can help policymakers to develop their policies according to the requirements and enhance vaccination programs.

A novel state space reduction algorithm for team formation in social networks

Team formation (TF) in social networks exploits graphs (i.e., vertices = experts and edges = skills) to represent a possible collaboration between the experts. These networks lead us towards building cost-effective research teams irrespective of the geolocation of the experts and the size of the dataset. Previously, large datasets were not closely inspected for the large-scale distributions & relationships among the researchers, resulting in the algorithms failing to scale well on the data. Therefore, this paper presents a novel TF algorithm for expert team formation called SSR-TF based on two metrics; communication cost and graph reduction, that will become a basis for future TF's. In SSR-TF, communication cost finds the possibility of collaboration between researchers. The graph reduction scales the large data to only appropriate skills and the experts, resulting in real-time extraction of experts for collaboration. This approach is tested on five organic and benchmark datasets, i.e., UMP, DBLP, ACM, IMDB, and Bibsonomy. The SSR-TF algorithm is able to build cost-effective teams with the most appropriate experts-resulting in the formation of more communicative teams with high expertise levels.

HLA Class-II‒Restricted CD8+ T Cells Contribute to the Promiscuous Immune Response in Dapsone-Hypersensitive Patients

HLA-B∗13:01 is associated with dapsone (DDS)-induced hypersensitivity, and it has been shown that CD4+ and CD8+ T cells are activated by DDS and its nitroso metabolite (nitroso dapsone [DDS-NO]). However, there is a need to define the importance of the HLA association in the disease pathogenesis. Thus, DDS- and DDS-NO‒specific CD8+ T-cell clones (TCCs) were generated from hypersensitive patients expressing HLA-B∗13:01 and were assessed for phenotype and function, HLA allele restriction, and killing of target cells. CD8+ TCCs were stimulated to proliferate and secrete effector molecules when exposed to DDS and/or DDS-NO. DDS-responsive and several DDS-NO‒responsive TCCs expressing a variety of TCR sequences displayed HLA class-I restriction, with the drug (metabolite) interacting with multiple HLA-B alleles. However, activation of certain DDS-NO‒responsive CD8+ TCCs was inhibited with HLA class-II block, with DDS-NO binding to HLA-DQB1∗05:01. These TCCs were of different origin but expressed TCRs displaying the same amino acid sequences. They were activated through a hapten pathway; displayed CD45RO, CD28, PD-1, and CTLA-4 surface molecules; secreted the same panel of effector molecules as HLA class-I‒restricted TCCs; but displayed a lower capacity to lyse target cells. To conclude, DDS and DDS-NO interact with a number of HLA molecules to activate CD8+ TCCs, with HLA class-II‒restricted CD8+ TCCs that display hybrid CD4‒CD8 features also contributing to the promiscuous immune response that develops in patients.

P272 The need for vasodilators use prior to transradial cardiac catheterization in high volume cardiac center

Funding Acknowledgements

This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

Background

Radial artery spasm (RAS) is one of the most common complication encountered by operators while performing trans-radial artery cardiac catheterization. Due to the technological advances in recent years and the increase number of experts in high volume centers, the prophylactic use of vasodilators may be unnecessary. To date, there are no clear recommendations for using these vasodilators and when to be used in day to day practice. Basically, It depends on operators discretion and hospital protocol. Therefore, further research in this area is warranted due to the conflicting findings of the prior studies.

purpose

To evaluate the need of using prophylactic vasodilators prior to trans-radial approach in high volume cardiac center and to identify factors associated with the development of RAS.

Methods

It is a prospective, randomized, double blind and placebo-controlled trial conducted in a single high volume cardiac center in Saudi Arabia from July to November 2017. Patients who met the inclusion criteria were randomized to either a cocktail vasodilators (nitroglycerin and verapamil) or matching placebo (normal saline) in 1:1 ratio. Subjective definition of RAS was utilized, consistent with previous studies. The primary outcome is the development of RAS in both groups. The secondary outcome is identifying the factors associated with the development of RAS. The calculated sample size is 315 patients. Data analysis was performed using SPSS 20 and STATA 15 softwares. Multiple stepwise logistic regression was used to examine the association between the study variables and incidence of RAS.

Results

A total of 490 patients were randomized (244 in placebo and 246 in treatment groups). There were no differences in the baseline demographic and clinical characteristics between both groups. Significantly, higher proportion of patients on the placebo group had RAS compared to those on the treatment group (23% vs 11%; p = 0.001). After controlling for the other factors, patients on the treatment were less likely to develop RAS than those on the placebo (OR= 0.32; p &lt;0.001). The independent risk factors associated with the occurrence of RAS are: female gender (OR= 6.18; p &lt;0.001), multiple puncture attempts (OR= 2.83; p = 0.003), current smoking (OR= 3.02; p =0.03) and using dihydropyridine calcium channel blockers (OR= 4.60; p &lt;0.001). We did not find a significant relationship between operators’ level of experience and the occurrence of RAS.

Conclusion

The use of cocktail vasodilators reduces the incidence of RAS regardless to the hospital volume and operators experience. Further studies on factors associated with RAS is warranted.

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.

Knowledge of kindergarten and elementary schools’ teachers regarding attention deficit hyperactivity disorder

Background

Attention deficit hyperactivity disorder (ADHD) is one of the most common mental disorders that manifest among children. Despite the fact that the teacher's role is essential in the assessment and management of pupils with ADHD and the recommendation of participation of teachers for the success and efficiency of diagnoses and treatment, the vast majority of teachers have neither understanding nor knowledge of ADHD.

Objectives

The current study explores the kindergarten and elementary school teachers’ knowledge regarding early detection and management of ADHD.

Methods

Cross sectional survey using stratified random sampling technique was carried out in governmental and private elementary and kindergarten schools in four cities of Qassim region, Saudi Arabia.

Results

The study included 1095 teachers, 711 (59.3%) did not get information about ADHD during undergraduate studies. Teachers’ overall ADHD knowledge mean was 21.7 + 5.5 out of 38 marks. Teachers with high qualification degree and kindergarten specialty scored 56.4% and 60.2%, respectively. Teachers who attended conferences related to ADHD scored 64.5%, while teachers who read about ADHD or have been ever asked to diagnose/teach an ADHD student had 59.4% and 62.1%, respectively. The sources for those who got their information through reading were statistically significant in overall knowledge, general knowledge and treatment dimensions. As scientific studies and books were the highest with percentage of 24.6% and 23.3%, respectively, 4% and 3.6%, respectively, 3% and 3%, respectively. The level of ADHD knowledge perception showed that 76% of teachers were knowledgeable in relation to overall ADHD perception.

Conclusion

Teachers who have higher qualifications or training in identifying ADHD children scored higher in our study.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].