184 research outputs found
DNA-like class R inhibitory oligonucleotides (INH-ODNs) preferentially block autoantigen-induced B-cell and dendritic cell activation in vitro and autoantibody production in lupus-prone MRL-Faslpr/lpr mice in vivo
INTRODUCTION. B cells have many different roles in systemic lupus erythematosus (SLE), ranging from autoantigen recognition and processing to effector functions (for example, autoantibody and cytokine secretion). Recent studies have shown that intracellular nucleic acid-sensing receptors, Toll-like receptor (TLR) 7 and TLR9, play an important role in the pathogenesis of SLE. Dual engagement of rheumatoid factor-specific AM14 B cells through the B-cell receptor (BCR) and TLR7/9 results in marked proliferation of autoimmune B cells. Thus, strategies to preferentially block innate activation through TLRs in autoimmune B cells may be preferred over non-selective B-cell depletion. METHODS. We have developed a new generation of DNA-like compounds named class R inhibitory oligonucleotides (INH-ODNs). We tested their effectiveness in autoimmune B cells and interferon-alpha-producing dendritic cells in vitro and in lupus-prone MRL-Faslpr/lpr mice in vivo. RESULTS. Class R INH-ODNs have 10- to 30-fold higher inhibitory potency when autoreactive B cells are synergistically activated through the BCR and associated TLR7 or 9 than when stimulation occurs via non-BCR-engaged TLR7/9. Inhibition of TLR9 requires the presence of both CCT and GGG triplets in an INH-ODN, whereas the inhibition of the TLR7 pathway appears to be sequence-independent but dependent on the phosphorothioate backbone. This difference was also observed in the MRL-Faslpr/lpr mice in vivo, where the prototypic class R INH-ODN was more effective in curtailing abnormal autoantibody secretion and prolonging survival. CONCLUSIONS. The increased potency of class R INH-ODNs for autoreactive B cells and dendritic cells may be beneficial for lupus patients by providing pathway-specific inhibition yet allowing them to generate protective immune response when needed.National Institutes of Health (AI047374, AI064736); Alliance for Lupus Researc
Identification of novel orthonairoviruses from rodents and shrews in Gabon, Central Africa
In Africa, several emerging zoonotic viruses have been transmitted from small mammals such as rodents and shrews to humans. Although no clinical cases of small mammal-borne viral diseases have been reported in Central Africa, potential zoonotic viruses have been identified in rodents in the region. Therefore, we hypothesized that there may be unrecognized zoonotic viruses circulating in small mammals in Central Africa. Here, we investigated viruses that have been maintained among wild small mammals in Gabon to understand their potential risks to humans. We identified novel orthonairoviruses in 24.6 % of captured rodents and shrews from their kidney total RNA samples. Phylogenetic analysis revealed that the novel viruses, Lamusara virus (LMSV) and Lamgora virus, were closely related to Erve virus, which was previously identified in shrews of the genus Crocidura and has been suspected to cause neuropathogenic diseases in humans. Moreover, we show that the LMSV ovarian tumour domain protease, one of the virulence determination factors of orthonairoviruses, suppressed interferon signalling in human cells, suggesting the possible human pathogenicity of this virus. Taken together, our study demonstrates the presence of novel orthonairoviruses that may pose unrecognized risks of viral disease transmission in Gabon
Energy applications of ionic liquids
Ionic liquids offer a unique suite of properties that make them important candidates for a number of energy related applications. Cation–anion combinations that exhibit low volatility coupled with high electrochemical and thermal stability, as well as ionic conductivity, create the possibility of designing ideal electrolytes for batteries, super-capacitors, actuators, dye sensitised solar cells and thermoelectrochemical cells. In the field of water splitting to produce hydrogen they have been used to synthesize some of the best performing water oxidation catalysts and some members of the protic ionic liquid family co-catalyse an unusual, very high energy efficiency water oxidation process. As fuel cell electrolytes, the high proton conductivity of some of the protic ionic liquid family offers the potential of fuel cells operating in the optimum temperature region above 100 °C. Beyond electrochemical applications, the low vapour pressure of these liquids, along with their ability to offer tuneable functionality, also makes them ideal as CO2 absorbents for post-combustion CO2 capture. Similarly, the tuneable phase properties of the many members of this large family of salts are also allowing the creation of phase-change thermal energy storage materials having melting points tuned to the application. This perspective article provides an overview of these developing energy related applications of ionic liquids and offers some thoughts on the emerging challenges and opportunities
A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.
The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.
Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Effects of comorbid conditions on health-related quality of life in youth with Type 2 diabetes: the TODAY clinical trial.
AIM: To explore associations between health-related quality of life (HRQOL) and comorbidities in youth with Type 2 diabetes. PATIENTS & METHODS: Of 699 youth in the TODAY study, 685 (98%) had baseline HRQOL data, 649 (93%) at 6 months and 583 (83%) at 24 months. Comorbidities were defined by sustained abnormal values and treatment regimens. RESULTS: At baseline, 22.2% of participants demonstrated impaired HRQOL. Only depressive symptoms distinguished those with versus without impaired HRQOL and were significantly related to later impaired HRQOL (p < 0.0001). A significant correspondence between impaired HRQOL and number of comorbidities (p = 0.0003) was noted, but was driven by the presence of depressive symptoms. CONCLUSION: Results emphasize the need for evaluation of depressive symptoms. Other comorbidities did not have a significant impact on HRQOL in this cohort
Parental Characteristics Associated With Outcomes in Youth With Type 2 Diabetes: Results From the TODAY Clinical Trial.
OBJECTIVE: This study examined parental factors associated with outcomes of youth in the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial. RESEARCH DESIGN AND METHODS: Of 699 youth with type 2 diabetes in the TODAY cohort, 623 (89.1%) had a parent participate and provide data at baseline, including weight, HbA(1c), blood pressure, symptoms of depression, binge eating (BE), and medical history. Youth were followed 2–6.5 years. Data were analyzed using regression models and survival curve methods. RESULTS: Parental diabetes (43.6% of parents) was associated with higher baseline HbA(1c) (P < 0.0001) and failure of youths to maintain glycemic control on study treatment (53.6% vs. 38.2% failure rate among those without a diabetic parent, P = 0.0002). Parental hypertension (40.6% of parents) was associated with hypertension in youth during TODAY (40.4% vs. 27.4% of youth with and without parental hypertension had hypertension, P = 0.0008) and with higher youth baseline BMI z scores (P = 0.0038). Parents had a mean baseline BMI of 33.6 kg/m(2). Parental obesity (BMI >30 kg/m(2)) was associated with higher baseline BMI z scores in the youth (P < 0.0001). Depressive symptoms in parents (20.6% of parents) were related to youth depressive symptoms at baseline only (P = 0.0430); subclinical BE in parents was related to the presence of subclinical BE (P = 0.0354) and depressive symptoms (P = 0.0326) in youth throughout the study period. CONCLUSIONS: Parental diabetes and hypertension were associated with lack of glycemic control, hypertension, and higher BMI z scores in youth. Further research is needed to better understand and address parental biological and behavioral factors to improve youth health outcomes
Longitudinal Correlates of Health Risk Behaviors in Children and Adolescents with Type 2 Diabetes.
OBJECTIVES: To characterize, over a two-year period, the proportion of youth with type 2 diabetes (T2D) enrolled in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study that reported ever at least trying smoking cigarettes and/or drinking alcohol. STUDY DESIGN: Longitudinal data were examined for participants with T2D ages 10 to 18 years old at baseline. Youth psychosocial, parent/family, environmental, and biological correlates of trying health risk behaviors were tested via cross-sectional multivariate models at each time point. Longitudinal models were explored for selected factors. RESULTS: Data were obtained from the TODAY study’s ethnically diverse participants at baseline (N=644), 6-month (N=616), and 24-month (N=543) assessments. Percent of youth ever trying only smoking remained stable at 4%, only drinking alcohol increased from 17% to 26%, and both smoking and drinking increased from 10% to 18% over the two-year period. Factors related to trying health risk behaviors were older age, male sex, non-Hispanic White race-ethnicity, lower grades, more depressive symptoms and stressful life events. Depressive symptoms, stressful life events, and BMI Z-score (the latter with smoking only) were related to engagement in health risk behaviors over time. CONCLUSIONS: Youth with T2D who are already at risk for health complications and who reported engaging in activities that further increase the likelihood of life-threatening morbidities were characterized. Although most correlates of trying these risk behaviors are non-modifiable, intervention efforts may need to focus on potentially modifiable factors, such as depressive symptoms and lower grades
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