Traumatic bilateral dissection of cervical internal carotid artery in the wake of a car accident: A case report

Background Bilateral carotid artery dissection secondary to severe trauma is rare and can be potentially life -threatening if not diagnosed and treated properly. Case Presentation We report a 29-year-old female who was admitted to the emergency department after a car accident. The patient was conscious at the time of admission and presented with an initial Glasgow Coma Scale (GCS) of 15 presenting normal vital signs. The patient developed motor dysphasia with right upper limb paresis a few hours after the admission. Magnetic resonance imaging (MRI) revealed a bilateral cervical internal carotid artery (ICA) occlusion in addition to left frontal lobe infarct in a subacute phase. Medical management was successful and the patient was discharged from the hospital two weeks after the admission. Discussion Noninvasive vascular imagining modalities are merging as the gold standard in the early detection of carotid artery dissection (CAD). Typical pathognomonic findings on MRI include double lumen and intimal flap. The management with systemic anticoagulation or antiplatelet therapy is aimed to prevent the development of ischemic stroke. In case of medical therapy being ineffective or in case of complication or any disorders suffered by a patient, endovascular treatment is performed. Conclusion With early detection and proper management, traumatic dissection of cervical carotid artery can have a benign outcome. As for the current patient, medical treatment with anticoagulation was sufficient and surgical management was therefore not required. Improvement in the patients’ speech was observed; nevertheless the continuation of speech therapy was indicated

Measuring, in solution, multiple-fluorophore labeling by combining Fluorescence Correlation Spectroscopy and photobleaching

Determining the number of fluorescent entities that are coupled to a given molecule (DNA, protein, etc.) is a key point of numerous biological studies, especially those based on a single molecule approach. Reliable methods are important, in this context, not only to characterize the labeling process, but also to quantify interactions, for instance within molecular complexes. We combined Fluorescence Correlation Spectroscopy (FCS) and photobleaching experiments to measure the effective number of molecules and the molecular brightness as a function of the total fluorescence count rate on solutions of cDNA (containing a few percent of C bases labeled with Alexa Fluor 647). Here, photobleaching is used as a control parameter to vary the experimental outputs (brightness and number of molecules). Assuming a Poissonian distribution of the number of fluorescent labels per cDNA, the FCS-photobleaching data could be easily fit to yield the mean number of fluorescent labels per cDNA strand (@ 2). This number could not be determined solely on the basis of the cDNA brightness, because of both the statistical distribution of the number of fluorescent labels and their unknown brightness when incorporated in cDNA. The statistical distribution of the number of fluorophores labeling cDNA was confirmed by analyzing the photon count distribution (with the cumulant method), which showed clearly that the brightness of cDNA strands varies from one molecule to the other.Comment: 38 pages (avec les figures

Reversible Fluorescence Photoswitching in DNA

[Image: see text] We describe the engineering of reversible fluorescence photoswitching in DNA with high-density substitution, and its applications in advanced fluorescence microscopy methods. High-density labeling of DNA with cyanine dyes can be achieved by polymerase chain reaction using a modified DNA polymerase that has been evolved to efficiently incorporate Cy3- and Cy5-labeled cytosine base analogues into double-stranded DNA. The resulting biopolymer, “CyDNA”, displays hundreds of fluorophores per DNA strand and is strongly colored and highly fluorescent, although previous observations suggest that fluorescence quenching at such high density might be a concern, especially for Cy5. Herein, we first investigate the mechanisms of fluorescence quenching in CyDNA and we suggest that two different mechanisms, aggregate formation and resonance energy transfer, are responsible for fluorescence quenching at high labeling densities. Moreover, we have been able to re-engineer CyDNA into a reversible fluorescence photoswitchable biopolymer by using the properties of the Cy3–Cy5 pair. This novel biopolymer constitutes a new class of photoactive DNA-based nanomaterial and is of great interest for advanced microscopy applications. We show that reversible fluorescence photoswitching in CyDNA can be exploited in optical lock-in detection imaging. It also lays the foundations for improved and sequence-specific super-resolution fluorescence microscopy of DNA

Provider and lay perspectives on intra-uterine contraception: a global review

BACKGROUND: Intra-uterine contraception (IUC) involves the use of an intra-uterine device (IUD), a highly effective, long-acting, reversible contraceptive method. Historically, the popularity of IUC has waxed and waned across different world regions, due to policy choices and shifts in public opinion. However, despite its advantages and cost-effectiveness for programmes, IUC's contribution to contraceptive prevalence is currently negligible in many countries. This paper presents the results of a systematic review of the global literature on provider and lay perspectives on IUC. It aims to shed light on the reasons for low use of IUC and reflect on potential opportunities for the method's promotion. METHODS: A systematic search of the literature was conducted in four peer-reviewed journals and four electronic databases (MEDLINE, EMBASE, POPLINE, and Global Health). Screening resulted in the inclusion of 68 relevant publications. RESULTS: Most included studies were conducted in areas where IUD use is moderate or low. Findings are similar across these areas. Many providers have low or uneven levels of knowledge on IUC and limited training. Many wrongly believe that IUC entails serious side effects such as pelvic inflammatory disease (PID), and are reluctant to provide it to entire eligible categories, such as HIV-positive women. There is particular resistance to providing IUC to teenagers and nulliparae. Provider opinions may be more favourable towards the hormonal IUD. Some health-care providers choose IUC for themselves. Many members of the public have low knowledge and unfounded misconceptions about IUC, such as the fear of infertility. Some are concerned about the insertion and removal processes, and about its effect on menses. However, users of IUC are generally satisfied and report a number of benefits. Peers and providers exert a strong influence on women's attitudes. CONCLUSION: Both providers and lay people have inaccurate knowledge and misconceptions about IUC, which contribute to explaining its low use. However, many reported concerns and fears could be alleviated through correct information. Concerted efforts to train providers, combined with demand creation initiatives, could therefore boost the method's popularity. Further research is needed on provider and lay perspectives on IUDs in low- and middle-income countries

Wykorzystanie algorytmu RANSAC dla segmentacji chmur punktów 3D

The article presents a method for 3D point cloud segmentation. The point cloud comes from a FARO LS scanner - the device creates a dense point cloud, where 3D points are organized in the 2D table. The input data set consists of millions of 3D points - it makes widely known RANSAC algorithms unusable. We add some modifications to use RANSAC for such big data setsArtykuł prezentuje metodę segmentacji chmury punktów 3D. Segmentacja znajduje w chmurze (kracie) punktów kwadryki. Źródłem danych są chmury punktów uzyskane przy pomocy skanera FARO LS. Skany wykonane przy wykorzystaniu tego skanera charakteryzują się zapisem punktów w tablicy (stąd określenie 'krata' punktów), przy czym jej rozmiary są znaczne - w eksperymentach wykorzystano kratę liczącą 9600x3960, co daje 38 016 000 punktów, podkreślając znaczenie czynnika złożoności pamięciowej algorytmów. Przedstawione rozwiązanie uwzględnia ten problem wywołując czasochłonny algorytm RANSAC jedynie dla wycinków analizowanej sceny, a następnie wykorzystuje uzyskane rezultaty do dalszej analizy. W artykule zaprezentowano szczegółowo algorytm RANSAC i zasady analizy wycinków skanu. Dane wejściowe dla algorytmu reprezentują scenę utworzoną przez człowieka (wnętrze pomieszczenia), co oznacza pojawianie się wielu płaszczyzn i innych prostych obiektów geometrycznych (np. wycinków walca). Prezentowane rozwiązanie pozwala na odnalezienie w scenie kwadryk, rozwiązanie takie pozwala objąć wiele kształtów tworzonych przez człowieka. W przeprowadzonych eksperymentach analizowano skan jadalni Willi Caro - dziewiętnastowiecznej willi, będącej jedną z siedzib Muzeum w Gliwicach. Wybór takiego przedmiotu eksperymentów jest powiązany z jednym z docelowych zastosowań - skanowaniem obiektów dziedzictwa kulturowego celem dokonania ich inwentaryzacji architektonicznej. Wyznaczenie kwadryk opisujących fragmenty skanu pozwala dobrać dokładność skanowania (zwiększenie dokładności dla wybranych fragmentów - detali artystycznych) w zależności od złożoności powierzchni. Ilustracje 1-3 prezentują analizowany skan, ilustracja nr 4 przedstawia punkty przypisane do kwadryk (wszystkich znalezionych przez oprogramowanie), a nr 5 zintegrowane kwadryki dla jednej ze ścian jadalni. W wyniku analizy znaleziono 299 kwadryk (o rozmiarach od 210 do 20512), które po integracji utworzyły 85 zintegrowanych powierzchni (wiele z nich to jednak pojedyncze kwadryki z pierwszego etapu przedstawiania, dla których nie znaleziono odpowiedników)

Fluorescence lifetime of actin in the familial hypertrophic cardiomyopathy transgenic heart

Clinical studies have revealed that the D166V mutation in the ventricular myosin regulatory light chain (RLC) can cause a malignant phenotype of familial hypertrophic cardiomyopathy (FHC). It has been proposed that RLC induced FHC in the heart originates at the level of the myosin cross-bridge due to alterations in the rates of cross-bridge cycling. In this report, we examine whether the environment of an active cross-bridge in cardiac myofibrils from transgenic (Tg) mice is altered by the D166V mutation in RLC. The cross-bridge environment was monitored by tracking the fluorescence lifetime (tau) of Alexa488-phalloidin-labeled actin. The fluorescence lifetime is the average rate of decay of a fluorescent species from the excited state, which strongly depends on various environmental factors. We observed that the lifetime was high when cross-bridges were bound to actin and low when they were dissociated from it. The lifetime was measured every 50 ms from the center half of the I-band during 60 s of rigor, relaxation and contraction of muscle. We found no differences between lifetimes of Tg-WT and Tg-D166V muscle during rigor, relaxation and contraction. The duty ratio expressed as a fraction of time that cross-bridges spend attached to the thin filaments during isometric contraction was similar in Tg-WT and Tg-D166V muscles. Since independent measurements showed a large decrease in the cross-bridge turnover rate in Tg-D166V muscle compared to Tg-WT, the fact that the duty cycle remains constant suggests that the D166V mutation of RLC causes a decrease in the rate of cross-bridge attachment to actin

Single Molecule Kinetics in the Familial Hypertrophic Cardiomyopathy RLC-R58Q Mutant Mouse Heart

One of the sarcomeric mutations associated with a malignant phenotype of Familial Hypertrophic Cardiomyopathy (FHC) is the D166V point mutation in the ventricular myosin regulatory light chain (RLC) encoded by the MYL2 gene. In this report we show that the rates of myosin cross-bridge attachment and dissociation are significantly different in isometrically contracting cardiac myofibrils from right ventricles of transgenic (Tg)-D166V and Tg-WT mice. We have derived the myosin cross-bridge kinetic rates by tracking the orientation of a fluorescently labeled single actin molecule. Orientation (measured by polarized fluorescence) oscillated between two states, corresponding to the actin-bound and actin-free states of the myosin cross-bridge. The rate of cross-bridge attachment during isometric contraction decreased from 3 s(−1) in myofibrils from Tg-WT to1.4 s(−1) in myofibrils from Tg-D166V. The rate of detachment decreased from 1.3 s(−1) (Tg-WT) to 1.2 s(−1) (Tg-D166V). We also showed that the level of RLC phosphorylation was largely decreased in Tg-D166V myofibrils compared to Tg-WT. Our findings suggest that alterations in the myosin cross-bridge kinetics brought about by the D166V mutation in RLC might be responsible for the compromised function of the mutated hearts and lead to their inability to efficiently pump blood

Cross-bridge kinetics in myofibrils containing familial hypertrophic cardiomyopathy R58Q mutation in the regulatory light chain of myosin

Familial hypertrophic cardiomyopathy (FHC) is a heritable form of cardiac hypertrophy caused by single-point mutations in genes encoding sarcomeric proteins including ventricular myosin regulatory light chain (RLC). FHC often leads to malignant outcomes and sudden cardiac death. The FHC mutations are believed to alter the kinetics of the interaction between actin and myosin resulting in inefficient energy utilization and compromised function of the heart. We studied the effect of the FHC-linked R58Q-RLC mutation on the kinetics of transgenic (Tg)-R58Q cardiac myofibrils. Kinetics was determined from the rate of change of orientation of actin monomers during muscle contraction. Actin monomers change orientation because myosin cross-bridges deliver periodic force impulses to it. An individual impulse (but not time average of impulses) carries the information about the kinetics of actomyosin interaction. To observe individual impulses it was necessary to scale down the experiments to the level of a few molecules. A small population (∼4 molecules) was selected by using (deliberately) inefficient fluorescence labeling and observing fluorescent molecules by a confocal microscope. We show that the kinetic rates are significantly smaller in the contracting cardiac myofibrils from Tg-R58Q mice then in control Tg-wild type (WT). We also demonstrate a lower force per cross-section of muscle fiber in Tg-R58Q versus Tg-WT mice. We conclude that the R58Q mutation-induced decrease in cross-bridge kinetics underlines the mechanism by which Tg-R58Q fibers develop low force and thus compromise the ability of the mutated heart to efficiently pump blood.11 page(s