Endovascular Treatment of Intracranial Dural Arteriovenous Fistulas: A German Single-Center Experience

Background and Purpose:Intracranial dural arteriovenous fistulas (DAVFs) are abnormal shunts between dural arteries and dural venous sinus or cortical veins. We report our experience with endovascular therapy of primary complex DAVFs using modern embolic agents.Methods:This is a retrospective analysis of patients with DAVFs treated between 2015 and 2019. Patient demographics and technical aspects including the use of embolic agent, access to the fistula, number of treatments, occlusion rates, and complications were addressed. Angiographic treatment success was defined as complete occlusion (CO) of the DAVF.Results:Fifty patients were treated endovascularly. Median age was 61 years and 66% were men. The most common symptom was pulsatile tinnitus in 17 patients (34%). The most frequent location of the DAVF was the transverse-sigmoid sinus (40%). Thirty-six fistulas (72%) had cortical venous reflux. Nonadhesive and adhesive liquid agents were used in 92% as a single material or in combination. CO was achieved in 48 patients (96%). In 28 individuals (56%), only 1 procedure was necessary. Nonadhesive liquid agents were exclusively used in 14 patients (28%) with CO attained in every case. For CO of tentorial DAVFs, multiple sessions were more often required than at the other locations (55 vs. 14%,p= 0.0051). Among 93 procedures, the overall complication rate was 3%. The procedure-related mortality rate was 0%.Conclusion:Endovascular treatment of intracranial DAVFs is feasible, safe, and effective with high rates of CO. In more than half of the patients, the DAVF was completely occluded after a single procedure. However, in tentorial DAVFs, multiple sessions were more often required

Endovascular treatment of intracranial dural arteriovenous fistulas

$\textit {Background and Purpose:}$ Intracranial dural arteriovenous fistulas (DAVFs) are abnormal shunts between dural arteries and dural venous sinus or cortical veins. We report our experience with endovascular therapy of primary complex DAVFs using modern embolic agents. $\textit {Methods:}$ This is a retrospective analysis of patients with DAVFs treated between 2015 and 2019. Patient demographics and technical aspects including the use of embolic agent, access to the fistula, number of treatments, occlusion rates, and complications were addressed. Angiographic treatment success was defined as complete occlusion (CO) of the DAVF. $\textit {Results:}$ Fifty patients were treated endovascularly. Median age was 61 years and 66% were men. The most common symptom was pulsatile tinnitus in 17 patients (34%). The most frequent location of the DAVF was the transverse-sigmoid sinus (40%). Thirty-six fistulas (72%) had cortical venous reflux. Nonadhesive and adhesive liquid agents were used in 92% as a single material or in combination. CO was achieved in 48 patients (96%). In 28 individuals (56%), only 1 procedure was necessary. Nonadhesive liquid agents were exclusively used in 14 patients (28%) with CO attained in every case. For CO of tentorial DAVFs, multiple sessions were more often required than at the other locations (55 vs. 14%, $\it p$ = 0.0051). Among 93 procedures, the overall complication rate was 3%. The procedure-related mortality rate was 0%. $\textit {Conclusion:}$ Endovascular treatment of intracranial DAVFs is feasible, safe, and effective with high rates of CO. In more than half of the patients, the DAVF was completely occluded after a single procedure. However, in tentorial DAVFs, multiple sessions were more often required

Profiling of short RNAs during fleshy fruit development reveals stage-specific sRNAome expression patterns

Plants feature a particularly diverse population of short (s)RNAs, the central component of all RNA silencing pathways. Next generation sequencing techniques enable deeper insights into this complex and highly conserved mechanism and allow identification and quantification of sRNAs. We employed deep sequencing to monitor the sRNAome of developing tomato fruits covering the period between closed flowers and ripened fruits by profiling sRNAs at 10 time-points. It is known that microRNAs (miRNAs) play an important role in development but very little information is available about the majority of sRNAs that are not miRNAs. Here we show distinctive patterns of sRNA expression that often coincide with stages of the developmental process such as flowering, early and late fruit maturation. Moreover, thousands of non-miRNA sRNAs are differentially expressed during fruit development and ripening. Some of these differentially expressed sRNAs derived from transposons but many derive from protein coding genes or regions that show homology to protein coding genes, several of which are known to play a role in flower and fruit development. These findings raise the possibility of a regulative role of these sRNAs during fruit onset and maturation in a crop species. We also identified six new miRNAs and experimentally validated two target mRNAs. These two mRNAs are targeted by the same miRNA but do not belong to the same gene family, which is rare for plant miRNAs. Expression pattern and putative function of these targets indicate a possible role in glutamate accumulation, which contributes to establishing the taste of the fruit

Electron Paramagnetic Resonance Spectroscopy of Nitroxide-Labeled Calmodulin

Calmodulin (CaM) is a highly conserved calcium-binding protein consisting of two homologous domains, each of which contains two EF-hands, that is known to bind well over 300 proteins and peptides. In most cases the (Ca(2+))(4)-form of CaM leads to the activation of a key regulatory enzyme or protein in a myriad of biological processes. Using the nitroxide spin-labeling reagent, 3-(2-iodoacetamido)-2,2,5,5-tetramethyl-1-pyrrolidinyl oxyl, bovine brain CaM was modified at 2-3 methionines with retention of activity as judged by the activation of cyclic nucleotide phosphodiesterase. X-band electron paramagnetic resonance (EPR) spectroscopy was used to measure the spectral changes upon addition of Ca(2+) to the apo-form of spin-labeled protein. A significant loss of spectral intensity, arising primarily from reductions in the heights of the low, intermediate, and high field peaks, accompanied Ca(2+) binding. The midpoint of the Ca(2+-)mediated transition determined by EPR occurred at a higher Ca(2+) concentration than that measured with circular dichroic spectroscopy and enzyme activation. Recent data have indicated that the transition from the apo-state of CaM to the fully saturated form, [Ca(2+))(4)-CaM], contains a compact intermediate corresponding to [Ca(2+))(2)-CaM], and the present results suggest that the spin probes are reporting on Ca(2+) binding to the last two sites in the N-terminal domain, i.e. for the [Ca(2+))(2)-CaM] → [Ca(2+))(4)-CaM] transition in which the compact structure becomes more extended. EPR of CaM, spin-labeled at methionines, offers a different approach for studying Ca(2+)-mediated conformational changes and may emerge as a useful technique for monitoring interactions with target proteins