Browsing by Subject "FIBRILLATION"

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  • Pirinen, Jani; Järvinen, Vesa; Martinez-Majander , Nicolas; Sinisalo, Juha; Pöyhönen, Pauli; Putaala, Jukka (2020)
    BACKGROUND: Ischemic stroke in young individuals often remains cryptogenic. Some of these strokes likely originate from the heart, and atrial fibrosis might be one of the etiological mechanisms. In this pilot study, we investigated whether advanced echocardiography findings of the left atrium (LA) of young cryptogenic stroke patients differ from those of stroke--free controls. METHODS AND RESULTS: We recruited 30 cryptogenic ischemic stroke patients aged 18 to 49 years and 30 age--and sex-matched stroke--free controls among participants of the SECRETO (Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome) study (NCT01934725). We measured basic left ventricular parameters and detailed measures of the LA, including 4--dimensional volumetry, speckle tracking epsilon, strain rate, and LA appendix orifice variation. Data were compared as continuous parameters and by tertiles. Compared with controls, stroke patients had smaller LA reservoir volumes (10.2 [interquartile range, 5.4] versus 13.2 [5.4] mL; P= 0.030) and smaller positive epsilon values (17.8 [8.5] versus 20.8 [10.1]; P= 0.023). In the tertile analysis, stroke patients had significantly lower left atrial appendage orifice variation (3.88 [0.75] versus 4.35 [0.90] mm; P=0.043), lower LA cyclic volume change (9.2 [2.8] versus 12.8 [3.5] mL; P=0.023), and lower LA contraction peak strain rate (-1.8 [0.6] versus -2.3 [0.6]; P=0.021). We found no statistically significant differences in left ventricular measures. CONCLUSIONS: This preliminary comparison suggests altered LA dynamics in young patients with cryptogenic ischemic stroke, and thus that LA wall pathology might contribute to these strokes. Our results await confirmation in a larger sample.
  • FINNRESUSCI Study Grp; Oksanen, Tuomas; Tiainen, Marjaana; Vaahersalo, Jukka; Bendel, Stepani; Varpula, Tero; Skrifvars, Markus; Pettilä, Ville; Wilkman, Erika (2018)
    Background: Optimal hemodynamic goals in post-resuscitation patients are not clear. Previous studies have reported an association between lower heart rate and good outcome in patients receiving targeted temperature management (TTM) after out-of-hospital cardiac arrest. Methods: We analyzed heart rate (HR) and outcome data of 504 post-resuscitation patients from the prospectively collected database of the FINNRESUSCI study. One-year neurologic outcome was dichotomized by the Cerebral Performance Category (CPC) to good (1-2) or poor (3-5). Results: Of 504 patients, 40.1% (202/504) had good and 59.9% (302/504) had poor one-year neurologic outcome. Patients with good outcome had lower time-weighted mean HR during the first 48 h in the ICU (69.2 bpm [59.2-75.1] vs. 76.6 bpm [65.72-89.6], p <0.001) and the first 72 h in the ICU (71.2 bpm [65.0-79.0] vs. 77.1 bpm [69.1-90.1, p <0.001]). The percentage of HR registrations below HR threshold values (60, 80 and 100 bpm) were higher for patients with good neurologic outcome, p <0.001 for all. Lower time-weighted HR for 0-48 h and 0-72 h, and a higher percentage of HR recordings below threshold values were independently associated with good neurological one-year outcome (p <0.05 for all). When TTM and non-TTM patients were analyzed separately, HR parameters were independently associated with one-year neurologic outcome only in non-TTM patients. Conclusion: Lower heart rate was independently associated with good neurologic outcome. Whether HR in post-resuscitation patients is a prognostic indicator or an important variable to be targeted by treatment, needs to be assessed in future prospective controlled clinical trials.
  • Li, Yunzhan; Liu, Zehua; Li, Li; Lian, Wenhua; He, Yaohui; Khalil, Elbadry; Makila, Ermei; Zhang, Wenzhong; Torrieri, Giulia; Liu, Xueyan; Su, Jingyi; Xiu, Yuanming; Fontana, Flavia; Salonen, Jarno; Hirvonen, Jouni; Liu, Wen; Zhang, Hongbo; Santos, Hélder A.; Deng, Xianming (2020)
    The analysis of nanoparticles' biocompatibility and immunogenicity is mostly performed under a healthy condition. However, more clinically relevant evaluation conducted under pathological condition is less known. Here, the immunogenicity and bio-nano interactions of porous silicon nanoparticles (PSi NPs) are evaluated in an acute liver inflammation mice model. Interestingly, a new mechanism in which PSi NPs can remit the hepatocellular damage and inflammation activation in a surface dependent manner through protein corona formation, which perturbs the inflammation by capturing the pro-inflammatory signaling proteins that are inordinately excreted or exposed under pathological condition, is found. This signal sequestration further attenuates the nuclear factor kappa B pathway activation and cytokines production from macrophages. Hence, the study proposes a potential mechanism for elucidating the altered immunogenicity of nanomaterials under pathological conditions, which might further offer insights to establish harmonized standards for assessing the biosafety of biomaterials in a disease-specific or personalized manner.
  • Ezzat, Kariem; Pernemalm, Maria; Palsson, Sandra; Roberts, Thomas C.; Järver, Peter; Dondalska, Aleksandra; Bestas, Burcu; Sobkowiak, Michal J.; Levänen, Bettina; Sköld, Magnus; Thompson, Elizabeth A.; Saher, Osama; Kari, Otto K.; Lajunen, Tatu; Ekstrom, Eva Sverremark; Nilsson, Caroline; Ishchenko, Yevheniia; Malm, Tarja; Wood, Matthew J. A.; Power, Ultan F.; Masich, Sergej; Linden, Anders; Sandberg, Johan K.; Lehtiö, Janne; Spetz, Anna-Lena; EL Andaloussi, Samir (2019)
    Artificial nanoparticles accumulate a protein corona layer in biological fluids, which significantly influences their bioactivity. As nanosized obligate intracellular parasites, viruses share many biophysical properties with artificial nanoparticles in extracellular environments and here we show that respiratory syncytial virus (RSV) and herpes simplex virus type 1 (HSV-1) accumulate a rich and distinctive protein corona in different biological fluids. Moreover, we show that corona pre-coating differentially affects viral infectivity and immune cell activation. In addition, we demonstrate that viruses bind amyloidogenic peptides in their corona and catalyze amyloid formation via surface-assisted heterogeneous nucleation. Importantly, we show that HSV-1 catalyzes the aggregation of the amyloid beta-peptide (A beta(42)), a major constituent of amyloid plaques in Alzheimer's disease, in vitro and in animal models. Our results highlight the viral protein corona as an acquired structural layer that is critical for viral-host interactions and illustrate a mechanistic convergence between viral and amyloid pathologies.
  • Maleki, Reza; Khedri, Mohammad; Rezvantalab, Sima; Afsharchi, Fatemeh; Musaie, Kiyan; Shafiee, Sepehr; Shahbazi, Mohammad-Ali (2021)
    Cytotoxic aggregation of misfolded beta-amyloid (A beta) proteins is the main culprit suspected to be behind the development of Alzheimer's disease (AD). In this study, A beta interactions with the novel two-dimensional (2D) covalent organic frameworks (COFs) as therapeutic options for avoiding beta-amyloid aggregation have been investigated. The results from multi-scale atomistic simulations suggest that amine-functionalized COFs with a large surface area (more than 1000 m(2)/gr) have the potential to prevent A beta aggregation. Gibb's free energy analysis confirmed that COFs could prevent protofibril self-assembly in addition to inhibiting beta-amyloid aggregation. Additionally, it was observed that the amine functional group and high contact area could improve the inhibitory effect of COFs on A beta aggregation and enhance the diffusivity of COFs through the blood-brain barrier (BBB). In addition, microsecond coarse-grained (CG) simulations with three hundred amyloids reveal that the presence of COFs creates instability in the structure of amyloids and consequently prevents the fibrillation. These results suggest promising applications of engineered COFs in the treatment of AD and provide a new perspective on future experimental research.