BackgroundWe investigated the prevalence of post-procedural headache in patients who have undergone thrombectomy for ischemic stroke, and correlated history of migraine with risk of peri-procedural complications. A total of 314 patients underwent thrombectomy at the Danish National Hospital from January 2012 to December 2014. Eligible subjects were phone-interviewed using a purpose-developed semi-structured questionnaire according to the International Classification of Headache Disorders 3, beta version criteria.FindingsAmong 96 eligible subjects, there was a significant decrease in migraine (p = 0.022) within the first 3 months after EVT compared to 1 year before treatment, which was further evident at interview time (on average 1.6 years after EVT, p = 0.013). A minority of patients experienced headaches for the first time within 3 months of their EVT (migraine 2, TTH 9), which persisted at interview time for subjects with migraine. Out of 12 subjects with peri-procedural complications, 2 had a history of migraine with aura.ConclusionThrombectomy leads to a significant decrease in previously known migraine, and new onset of headache in a small subset of patients. A history of migraine does not appear to predispose to peri-procedural complications.Electronic supplementary materialThe online version of this article (doi:10.1186/s10194-017-0719-0) contains supplementary material, which is available to authorized users.

DNA unzipping, the separation of its double helix into single strands, is crucial in modulating a host of genetic processes. Although the large-scale separation of double-stranded DNA has been studied with a variety of theoretical and experimental techniques, the minute details of the very first steps of unzipping are still unclear. Here, we use atomistic molecular-dynamics simulations, coarse-grained simulations, and a statistical-mechanical model to study the initiation of DNA unzipping by an external force. Calculation of the potential of mean force profiles for the initial separation of the first few terminal basepairs in a DNA oligomer revealed that forces ranging between 130 and 230 pN are needed to disrupt the first basepair, and these values are an order of magnitude larger than those needed to disrupt basepairs in partially unzipped DNA. The force peak has an echo of ∼50 pN at the distance that unzips the second basepair. We show that the high peak needed to initiate unzipping derives from a free-energy basin that is distinct from the basins of subsequent basepairs because of entropic contributions, and we highlight the microscopic origin of the peak. To our knowledge, our results suggest a new window of exploration for single-molecule experiments.

Abstract. A class of nucleosome remodeling motors translocate nucleosomes, to which they are attached, toward the middle of DNA chain in the presence of ATP during in vitro experiments. Such a biological activity is likely based on a physical mechanism for detecting and comparing the lengths of the flanking polymer chains. Here we propose that a pivoting mode of DNA fluctuations near the surface of the nucleosome coupled with binding reaction with a DNA binding site of the motor provides a physical basis for length detection. Since the mean frequency of fluctuations is higher for a shorter chain than a longer one due to its lower drag coefficient, a shorter chain has a higher rate of receptor binding, which triggers the ATP-dependent activity of the remodeling motor. Dimerization of such units allows the motor to compare the length of the flanking DNA chains, enabling the translocation of the nucleosome toward the center of the DNA.

Background The present case contributes to the limited literature on central nervous system involvement of blastic plasmacytoid dendritic cell neoplasm (BPDCN).  Case presentation  A 63-year-old male presented to the department of neurology with a three-day history of rapidly progressing headache, fatigue, and confusion. Physical examination revealed multiple bruise-like skin lesions. Initial laboratory workup raised suspicion of acute leukemia, and a brain computer tomography identified several hyperdense processes. A bone marrow biopsy gave the diagnosis BPDCN, a rare and aggressive hematologic malignancy derived from plasmacytoid dendritic cells with a poor prognosis. Lumbar puncture showed not only signs of BPDCN, but also cerebral toxoplasmosis, thus providing a differential diagnosis. Despite intensive systemic and intrathecal chemotherapy, the patient died 25 days later due to multi-organ failure. Discussion The exact incidence of BPDCN is unknown and perhaps underestimated but may account for 0.5 – 1% of all hematological malignancies. The median age at onset is 60 to 70 years, and most patients are men. Cutaneous lesions are the most frequent clinical manifestation at diagnosis. Other symptoms present at time of diagnosis or during disease progression include lymphadenopathy, splenomegaly and cytopenia caused by bone marrow involvement. Although the majority of BPDCN patients have no symptoms or signs of central nervous system involvement, plasmacytoid dendritic cells have been detected in the cerebrospinal fluid in more than 50%. Conclusions This case highlights the importance of considering hematological malignancies as a differential diagnosis in patients developing acute neurological symptoms and raises suspicion of a possible association between toxoplasmosis and hematological malignancies.