12 research outputs found
Persistent humoral and CD4 + T H cell immunity after mild SARS-COV-2 infection—The CoNAN long-term study
Understanding persistent cellular and humoral immune responses to SARS-CoV-2 will be of major importance to terminate the ongoing pandemic. Here, we assessed long-term immunity in individuals with mild COVID-19 up to 1 year after a localized SARS-CoV-2 outbreak. CoNAN was a longitudinal population-based cohort study performed 1.5 months, 6 months, and 12 months after a SARS-CoV-2 outbreak in a rural German community. We performed a time series of five different IgG immunoassays assessing SARS-CoV-2 antibody responses on serum samples from individuals that had been tested positive after a SARS-CoV-2 outbreak and in control individuals who had a negative PCR result. These analyses were complemented with the determination of spike-antigen specific TH cell responses in the same individuals. All infected participants were presented as asymptomatic or mild cases. Participants initially tested positive for SARS-CoV-2 infection either with PCR, antibody testing, or both had a rapid initial decline in the serum antibody levels in all serological tests but showed a persisting T H cell immunity as assessed by the detection of SARS-CoV-2 specificity of T H cells for up to 1 year after infection. Our data support the notion of a persistent T-cell immunity in mild and asymptomatic cases of SARS-CoV-2 up to 1 year after infection. We show that antibody titers decline over 1 year, but considering several test results, complete seroreversion is rare. Trial registration German Clinical Trials Register DRKS00022416
Marathon-Induced Cardiac Strain as Model for the Evaluation of Diagnostic microRNAs for Acute Myocardial Infarction
Background: The current gold standard biomarker for myocardial infarction (MI), cardiac
troponin (cTn), is recognized for its high sensitivity and organ specificity; however, it lacks diagnostic
specificity. Numerous studies have introduced circulating microRNAs as potential biomarkers for
MI. This study investigates the MI-specificity of these serum microRNAs by investigating myocardial
stress/injury due to strenuous exercise. Methods: MicroRNA biomarkers were retrieved by compre hensive review of 109 publications on diagnostic serum microRNAs for MI. MicroRNA levels were
first measured by next-generation sequencing in pooled sera from runners (n = 46) before and after
conducting a full competitive marathon. Hereafter, reverse transcription quantitative real-time PCR
(qPCR) of 10 selected serum microRNAs in 210 marathon runners was performed (>10,000 qPCR
measurements). Results: 27 potential diagnostic microRNA for MI were retrieved by the literature
review. Eight microRNAs (miR-1-3p, miR-21-5p, miR-26a-5p, miR-122-5p, miR-133a-3p, miR-142-5p,
miR-191-5p, miR-486-3p) showed positive correlations with cTnT in marathon runners, whereas
two miRNAs (miR-134-5p and miR-499a-5p) showed no correlations. Upregulation of miR-133a-3p
(p = 0.03) and miR-142-5p (p = 0.01) went along with elevated cTnT after marathon. Conclusion: Some
MI-associated microRNAs (e.g., miR-133a-3p and miR-142-5p) have similar kinetics under strenuous
exercise and MI as compared to cTnT, which suggests that their diagnostic specificity could be lim ited. In contrast, several MI-associated microRNAs (miR-26a-5p, miR-134-5p, miR-191-5p) showed
different release behavior; hence, combining cTnT with these microRNAs within a multi-marker
strategy may add diagnostic accuracy in MI
Marathon-Induced Cardiac Strain as Model for the Evaluation of Diagnostic microRNAs for Acute Myocardial Infarction
Background: The current gold standard biomarker for myocardial infarction (MI), cardiac troponin (cTn), is recognized for its high sensitivity and organ specificity; however, it lacks diagnostic specificity. Numerous studies have introduced circulating microRNAs as potential biomarkers for MI. This study investigates the MI-specificity of these serum microRNAs by investigating myocardial stress/injury due to strenuous exercise. Methods: MicroRNA biomarkers were retrieved by comprehensive review of 109 publications on diagnostic serum microRNAs for MI. MicroRNA levels were first measured by next-generation sequencing in pooled sera from runners (n = 46) before and after conducting a full competitive marathon. Hereafter, reverse transcription quantitative real-time PCR (qPCR) of 10 selected serum microRNAs in 210 marathon runners was performed (>10,000 qPCR measurements). Results: 27 potential diagnostic microRNA for MI were retrieved by the literature review. Eight microRNAs (miR-1-3p, miR-21-5p, miR-26a-5p, miR-122-5p, miR-133a-3p, miR-142-5p, miR-191-5p, miR-486-3p) showed positive correlations with cTnT in marathon runners, whereas two miRNAs (miR-134-5p and miR-499a-5p) showed no correlations. Upregulation of miR-133a-3p (p = 0.03) and miR-142-5p (p = 0.01) went along with elevated cTnT after marathon. Conclusion: Some MI-associated microRNAs (e.g., miR-133a-3p and miR-142-5p) have similar kinetics under strenuous exercise and MI as compared to cTnT, which suggests that their diagnostic specificity could be limited. In contrast, several MI-associated microRNAs (miR-26a-5p, miR-134-5p, miR-191-5p) showed different release behavior; hence, combining cTnT with these microRNAs within a multi-marker strategy may add diagnostic accuracy in MI
Persistent T-Cell Reactivity in a Seronegative Patient after SARS-CoV-2 Infection and One Vaccination
We present here a 64-year-old male participant of the CoNAN study who experienced a PCR-confirmed mild SARS-CoV-2 infection but did not develop any measurable antibody response. Additionally, after vaccination with ChAdOx1 (AstraZeneca, Cambridge, UK) 11 months later, no antibodies were detected in six serological tests three weeks after the vaccination. When we assessed T-helper (Th) cell immunity, SARS-CoV-2-specific Th cells produced detectable amounts of IFNÎł and TNF six weeks after the infection. A robust T-cell immunity remained detectable at least until six months after the infection and was boosted by the vaccination thereafter. This case report points out that an assessment of a prior infection or a vaccine response based solely on antibody detection might have limitations in individual patients
Early processing of emotional faces in a Go/NoGo task: lack of N170 right-hemispheric specialisation in children with major depression
Emotionally biased information processing towards sad and away from happy information characterises individuals with major depression. To learn more about the nature of these dysfunctional modulations, developmental and neural aspects of emotional face processing have to be considered. By combining measures of performance (attention control, inhibition) in an emotional Go/NoGo task with an event-related potential (ERP) of early face processing (N170), we obtained a multifaceted picture of emotional face processing in a sample of children and adolescents (11-14 years) with major depression (MDD, n = 26) and healthy controls (CTRL, n = 26). Subjects had to respond to emotional faces (fearful, happy or sad) and withhold their response to calm faces or vice versa. Children of the MDD group displayed shorter N170 latencies than children of the CTRL group. Typical right lateralisation of the N170 was observed for all faces in the CTRL but not for happy and calm faces in the MDD group. However, the MDD group did not differ in their behavioural reaction to emotional faces, and effects of interference by emotional information on the reaction to calm faces in this group were notably mild. Although we could not find a typical pattern of emotional bias, the results suggest that alterations in face processing of children with major depression can be seen at early stages of face perception indexed by the N170. The findings call for longitudinal examinations considering effects of development in children with major depression as well as associations to later stages of processing
Comparison of InAs nanowire conductivity: influence of growth method and structure
The conductivity and crystal structure of nominally undoped InAs nanowires deposited by three different methods – 1. selective area metal organic vapor phase epitaxy (SA MOVPE), 2. gold assisted vapor liquid solid (VLS) MOVPE and 3. extrinsic catalyst free VLS molecular beam epitaxy (MBE) – is investigated. The influence on conductivity by stacking faults and different growth conditions is analyzed to determine the main impact. It is found that in terms of crystal structure, nanowires deposited by VLS MOVPE and VLS MBE behave similarly showing a zinc blende (ZB) phase while nanowires deposited by SA MOVPE feature a high density of stacking faults and a tendency to higher amounts of wurtzite (WZ) when grown with a decreased growth rate. However, the conductivity of wires deposited by VLS MOVPE is found to be much higher and statistically less dispersive compared to the other two wire types. An electrical similarity between nominally undoped wires in VLS MOVPE and previously reported intentionally doped wires in SA MOVPE is observed and discussed. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Early processing of emotional faces in a Go/NoGo task: lack of N170 right-hemispheric specialisation in children with major depression
Emotionally biased information processing towards sad and away from happy information characterises individuals with major depression. To learn more about the nature of these dysfunctional modulations, developmental and neural aspects of emotional face processing have to be considered. By combining measures of performance (attention control, inhibition) in an emotional Go/NoGo task with an event-related potential (ERP) of early face processing (N170), we obtained a multifaceted picture of emotional face processing in a sample of children and adolescents (11-14 years) with major depression (MDD, n = 26) and healthy controls (CTRL, n = 26). Subjects had to respond to emotional faces (fearful, happy or sad) and withhold their response to calm faces or vice versa. Children of the MDD group displayed shorter N170 latencies than children of the CTRL group. Typical right lateralisation of the N170 was observed for all faces in the CTRL but not for happy and calm faces in the MDD group. However, the MDD group did not differ in their behavioural reaction to emotional faces, and effects of interference by emotional information on the reaction to calm faces in this group were notably mild. Although we could not find a typical pattern of emotional bias, the results suggest that alterations in face processing of children with major depression can be seen at early stages of face perception indexed by the N170. The findings call for longitudinal examinations considering effects of development in children with major depression as well as associations to later stages of processing