6 research outputs found
Interferon Gamma Release Assay Mitogen Responses in COVID-19
Background
Elevated cytokine release and T cell exhaustion have been associated with COVID-19 disease severity. T cell activity may be indirectly measured through interferon gamma release assays (IGRAs), which use mitogen stimulation of T lymphocytes as a positive control. In our institution, an unexpectedly high rate of indeterminate IGRAs was noted in COVID-19âpositive patients. We aimed to evaluate the clinical characteristics associated with indeterminate IGRA results and the difference in mitogen responses between COVID-19âpositive and COVID-19ânegative patients. Methods
We reviewed all patients, regardless of COVID status, who were admitted between March 1, 2020, and May 31, 2020, and for whom an IGRA was collected. For COVID-19âpositive individuals, we evaluated the statistical association of their IGRA results and clinical characteristics, including demographics, laboratory values, comorbidities, and hospitalization-related outcomes. For both COVID-19âpositive and COVID-19ânegative individuals, we evaluated IGRA mitogen control values relative to COVID-19 status as stratified by absolute lymphocyte count. Results
In COVID-19âpositive patients, indeterminate IGRA results were statistically associated with white blood cell count and other markers of inflammation. When comparing COVID-19âpositive and COVID-19ânegative patients, we noted a statistically significant difference in IGRA mitogen control values when stratified by absolute lymphocyte count. Conclusions
Indeterminate IGRA results were associated with higher levels of inflammatory markers. Furthermore, when comparing mitogen responses between COVID-19âpositive and COVID-19ânegative patients, there was an observed difference in T cell reactivity between the groups. The mitogen response in IGRAs may serve as a surrogate for T cell function and a marker of disease severity in COVID-19
Target treatment with stereotactic radiation for recurrent gliomas
High grade gliomas (HGG) have a propensity to recur locally and have poor outcomes. As such, safe and effective treatment is paramount. Target treatment with stereotactic radiation allows safe re-irradiation through minimizing normal brain tissue radiation due to its high precision. In this review, we evaluated the clinical experiences using SRS and FSRT for re-irradiation in HGG. We report the radiobiological advantages and disadvantages of both modalities as well as the safety and efficacy published in current literature
Post-conjunction detection of ÎČ Pictoris b with VLT/SPHERE
accepted by A&AInternational audienceContext. With an orbital distance comparable to that of Saturn in the solar system, ÎČ Pictoris b is the closest (semi-major axis â9 au) exoplanet that has been imaged to orbit a star. Thus it offers unique opportunities for detailed studies of its orbital, physical, and atmospheric properties, and of disk-planet interactions. With the exception of the discovery observations in 2003 with NaCo at the Very Large Telescope (VLT), all following astrometric measurements relative to ÎČ Pictoris have been obtained in the southwestern part of the orbit, which severely limits the determination of the planetâs orbital parameters.Aims. We aimed at further constraining ÎČ Pictoris b orbital properties using more data, and, in particular, data taken in the northeastern part of the orbit.Methods. We used SPHERE at the VLT to precisely monitor the orbital motion of beta ÎČ Pictoris b since first light of the instrument in 2014.Results. We were able to monitor the planet until November 2016, when its angular separation became too small (125 mas, i.e., 1.6 au) and prevented further detection. We redetected ÎČ Pictoris b on the northeast side of the disk at a separation of 139 mas and a PA of 30° in September 2018. The planetary orbit is now well constrained. With a semi-major axis (sma) of aâ=â9.0â
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0.5 au (1Ï), it definitely excludes previously reported possible long orbital periods, and excludes ÎČ Pictoris b as the origin of photometric variations that took place in 1981. We also refine the eccentricity and inclination of the planet. From an instrumental point of view, these data demonstrate that it is possible to detect, if they exist, young massive Jupiters that orbit at less than 2 au from a star that is 20 pc away