Asymptotic Analysis for Optimal Control of the Cattaneo Model

We consider an optimal control problem with tracking-type cost functional constrained by the Cattaneo equation, which is a well-known model for delayed heat transfer. In particular, we are interested the asymptotic behaviour of the optimal control problems for a vanishing delay time $\tau \rightarrow 0$. First, we show the convergence of solutions of the Cattaneo equation to the ones of the heat equation. Assuming the same right-hand side and compatible initial conditions for the equations, we prove a linear convergence rate. Moreover, we show linear convergence of the optimal states and optimal controls for the Cattaneo equation towards the ones for the heat equation. We present numerical results for both, the forward and the optimal control problem confirming these linear convergence rates

Proteomics : A Tool to Study Platelet Function

Acknowledgments: Authors acknowledge Laxmikanth Kollipara for the critical review and Julia Lill for support with figures preparation. The Figure 2 was created in Biorender.Peer reviewedPublisher PD

Nuclear medicine in the assessment and prevention of cancer therapy-related cardiotoxicity:prospects and proposal of use by the European Association of Nuclear Medicine (EANM)

Abstract: Cardiotoxicity may present as (pulmonary) hypertension, acute and chronic coronary syndromes, venous thromboembolism, cardiomyopathies/heart failure, arrhythmia, valvular heart disease, peripheral arterial disease, and myocarditis. Many of these disease entities can be diagnosed by established cardiovascular diagnostic pathways. Nuclear medicine, however, has proven promising in the diagnosis of cardiomyopathies/heart failure, and peri- and myocarditis as well as arterial inflammation. This article first outlines the spectrum of cardiotoxic cancer therapies and the potential side effects. This will be complemented by the definition of cardiotoxicity using non-nuclear cardiovascular imaging (echocardiography, CMR) and biomarkers. Available nuclear imaging techniques are then presented and specific suggestions are made for their application and potential role in the diagnosis of cardiotoxicity.</p

Decline in the number of patients with meningitis in German hospitals during the COVID-19 pandemic

BACKGROUND AND OBJECTIVES: In 2020, a wide range of hygiene measures was implemented to mitigate infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In consequence, pulmonary infections due to other respiratory pathogens also decreased. Here, we evaluated the number of bacterial and viral meningitis and encephalitis cases during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: In a multicentre retrospective analysis of data from January 2016 until December 2020, numbers of patients diagnosed with bacterial meningitis and other types of CNS infections (such as viral meningitis and encephalitis) at 26 German hospitals were studied. Furthermore, the number of common meningitis-preceding ear-nose-throat infections (sinusitis, mastoiditis and otitis media) was evaluated. RESULTS: Compared to the previous years, the total number of patients diagnosed with pneumococcal meningitis was reduced (n = 64 patients/year in 2020 vs. n = 87 to 120 patients/year between 2016 and 2019, all p < 0.05). Additionally, the total number of patients diagnosed with otolaryngological infections was significantly lower (n = 1181 patients/year in 2020 vs. n = 1525 to 1754 patients/year between 2016 and 2019, all p < 0.001). We also observed a decline in viral meningitis and especially enterovirus meningitis (n = 25 patients/year in 2020 vs. n = 97 to 181 patients/year between 2016 and 2019, all p < 0.001). DISCUSSION: This multicentre retrospective analysis demonstrates a decline in the number of patients treated for viral and pneumococcal meningitis as well as otolaryngological infections in 2020 compared to previous years. Since the latter often precedes pneumococcal meningitis, this may point to the significance of the direct spread of pneumococci from an otolaryngological focus such as mastoiditis to the brain as one important pathophysiological route in the development of pneumococcal meningitis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00415-022-11034-w

Pulsed electron avalanche knife (PEAK) PlasmaBlade™ in pacemaker and defibrillator procedures

Abstract Background The pulsed electron avalanche knife (PEAK) PlasmaBlade™ is an innovative electrosurgical device that uses a novel technology to cut tissues. It has been proven to be safe and feasible in ear, nose, and throat surgery, but there are only limited data concerning the use of PlasmaBlade™ instead of conventional electrocautery in cardiac implantable electronic device (CIED) procedures except for generator replacements. Methods We conducted a retrospective, single-center study with patients undergoing CIED surgery at our center between December 2015 and March 2017 and evaluate the feasibility and the clinical outcome of the PlasmaBlade™. Results 282 patients (mean age 70.7 ±  12.9 years; 65.6% male) were included, of which 119 (42.2%) underwent pacemaker implantation, 95 (33.7%) implantable cardioverter defibrillator implantation, and 68 (24.1%) received a generator replacement. At the time of the procedure, 55 patients (19.5%) were on dual antiplatelet therapy, and 109 (38.7%) patients were on oral anticoagulation (30.5% vitamin K antagonists, 8.2% novel oral anticoagulants). The overall perioperative complication rate was 3.9%. Device-pocket hematoma occurred in 9 patients (3.2%) requiring further surgery. No lead damage was seen within a follow-up of 6 months. One patient presented with device-pocket infection 2.9 months after implantation of a cardiac resynchronization therapy defibrillator requiring CIED system extraction. Conclusions Replacing conventional electrocautery by PlasmaBlade™ for CIED procedures is feasible with a moderate rate of perioperative complications compared to the literature. Studies comparing the PlasmaBlade™ with conventional electrocautery are necessary to investigate whether PlasmaBlade™ offers an additional benefit over conventional electrocautery

Cardiac dysfunction from cancer and cancer therapy: new pathways for the prevention of late cardiotoxicity

In contrast to adults, meningiomas are uncommon tumors in childhood and adolescence. Whether adult and pediatric meningiomas differ on a molecular level is unclear. Here we report detailed genomic analyses of 37 pediatric meningiomas by sequencing and DNA methylation profiling. Histologically, the series was dominated by meningioma subtypes with aggressive behavior, with 70% of patients suffering from WHO grade II or III meningiomas. The most frequent cytogenetic aberrations were loss of chromosomes 22 (23/37 [62%]), 1 (9/37 [24%]), 18 (7/37 [19%]), and 14 (5/37 [14%]). Tumors with NF2 alterations exhibited overall increased chromosomal instability. Unsupervised clustering of DNA methylation profiles revealed separation into three groups: designated group 1 composed of clear cell and papillary meningiomas, whereas group 2A comprised predominantly atypical meningiomas and group 2B enriched for rare high-grade subtypes (rhabdoid, chordoid). Meningiomas from NF2 patients clustered exclusively within groups 1 and 2A. When compared with a dataset of 105 adult meningiomas, the pediatric meningiomas largely grouped separately. Targeted panel DNA sequencing of 34 tumors revealed frequent NF2 alterations, while other typical alterations found in adult non-NF2 tumors were absent. These data demonstrate that pediatric meningiomas are characterized by molecular features distinct from adult tumors

Crosstalk between nitrite, myoglobin and reactive oxygen species to regulate vasodilation under hypoxia.

The systemic response to decreasing oxygen levels is hypoxic vasodilation. While this mechanism has been known for more than a century, the underlying cellular events have remained incompletely understood. Nitrite signaling is critically involved in vessel relaxation under hypoxia. This can be attributed to the presence of myoglobin in the vessel wall together with other potential nitrite reductases, which generate nitric oxide, one of the most potent vasodilatory signaling molecules. Questions remain relating to the precise concentration of nitrite and the exact dose-response relations between nitrite and myoglobin under hypoxia. It is furthermore unclear whether regulatory mechanisms exist which balance this interaction. Nitrite tissue levels were similar across all species investigated. We then investigated the exact fractional myoglobin desaturation in an ex vivo approach when gassing with 1% oxygen. Within a short time frame myoglobin desaturated to 58±12%. Given that myoglobin significantly contributes to nitrite reduction under hypoxia, dose-response experiments using physiological to pharmacological nitrite concentrations were conducted. Along all concentrations, abrogation of myoglobin in mice impaired vasodilation. As reactive oxygen species may counteract the vasodilatory response, we used superoxide dismutase and its mimic tempol as well as catalase and ebselen to reduce the levels of reactive oxygen species during hypoxic vasodilation. Incubation of tempol in conjunction with catalase alone and catalase/ebselen increased the vasodilatory response to nitrite. Our study shows that modest hypoxia leads to a significant nitrite-dependent vessel relaxation. This requires the presence of vascular myoglobin for both physiological and pharmacological nitrite levels. Reactive oxygen species, in turn, modulate this vasodilation response