Preconditioning is a promising technique to protect the heart from ischaemia-reperfusion injury. In this context, the crosstalk between different cardiac cell types and especially the exchange of cardioprotective mediators has come into the focus of current research. Recently, extracellular vesicles (EVs), nano-sized structures, emerged as possible communication mediators. They are taken up by recipient cells and can alter gene expression or activate intracellular signal cascades. It has been shown that all cardiac cell types are able to secrete EVs, but so far the influence of an in vitro preconditioning stimulus on EV concentration and composition has not been investigated. Therefore, we stimulated primary cardiac myocytes and fibroblasts from neonatal rats, as well as H9c2 cells, with two known in vitro preconditioning stimuli: hypoxia or isoflurane. EVs were isolated from cell culture supernatants 48 h after stimulation by differential centrifugation and size exclusion chromatography. They were characterized by transmission electron microscopy, tunable resistive pulse sensing, miRNA array and Western blot analysis. The detected EVs had the typical cup-shaped morphology and a size of about 150 nm. No significant differences in EV concentration were observed between the different groups. The protein and miRNA load was affected by in vitro preconditioning with isoflurane or hypoxia. EV markers like Alix, CD63, flotillin-1 and especially heat shock protein 70 were significantly up-regulated by the treatments. Several miRNAs like miR-92b-3p, miR-761 and miR-101a-5p were also significantly affected. A migration assay confirmed the physiological benefit of these EVs. Taken together, our findings show that a model of in vitro preconditioning of cardiac cells does not influence EV concentration but strongly regulates the EV cargo and affects migration. This might indicate a role for EV-mediated communication in isoflurane- and hypoxia-induced in vitro preconditioning.
In order to evaluate further the possibility that transient hypothyroidism and hyperthyrotropinemia in newborn infants could result from a state of relative iodine deficiency, the urinary concentration of iodine, used as an index of the dietary intake of iodine was determined in casual urine samples collected in 1,076 full-term infants aged 3–6 days in 16 cities in 10 different European countries and in Toronto, Canada. In addition, the results obtained by programs of systematic neonatal screening for congenital hypothyroidism in the same areas were compared. There were marked regional differences in iodine nutrition during the neonatal period in Europe (median urinary iodine: 16.2 μg/dl in Rotterdam, the Netherlands, and 1.1 μg/dl in Freiburg, FRG. A low iodine supply in newborn populations was accompanied by, and probably explained, an elevated frequency of transient disorders of thyroid function in young infants. Iodine prophylaxis is urgently needed in some European countries not only for the prevention of goiter, but mostly for the prevention of impairment of thyroid function during the critical period of brain development.
(99m)Tc-anti-E-selectin-Fab scintigraphy can be used successfully to image synovitis with better specificity than (99m)Tc-HDP bone scanning. The advantages over (111)In-1.2B6-F(ab')(2) are easier availability of the radionuclide, improved physical properties and optimal imaging 4 h after injection.
BackgroundAlthough macrophage migration inhibitory factor (MIF) has been demonstrated to mediate cardioprotection in ischemia/reperfusion injury and antagonize fibrotic effects through its receptor, CD74, the function of the soluble CD74 receptor ectodomain (sCD74) and its interaction with circulating MIF have not been explored in cardiac disease.Methods and ResultsCardiac fibroblasts were isolated from hearts of neonatal mice and differentiated into myofibroblasts. Co‐treatment with recombinant MIF and sCD74 induced cell death (P<0.001), which was mediated by receptor‐interacting serine/threonine‐protein kinase (RIP)1/RIP3‐dependent necroptosis (P=0.0376). This effect was specific for cardiac fibroblasts and did not affect cardiomyocytes. Gene expression analyses using microarray and RT‐qPCR technology revealed a 4‐fold upregulation of several interferon‐induced genes upon co‐treatment of myofibroblasts with sCD74 and MIF (Ifi44: P=0.011; Irg1: P=0.022; Clec4e: P=0.011). Furthermore, Western blot analysis confirmed the role of sCD74 as a modulator of MIF signaling by diminishing MIF‐mediated protein kinase B (AKT) activation (P=0.0197) and triggering p38 activation (P=0.0641). We obtained evidence that sCD74 inhibits MIF‐mediated survival pathway through the C‐X‐C chemokine receptor 4/AKT axis, enabling the induction of CD74‐dependent necroptotic processes in cardiac myofibroblasts. Preliminary clinical data revealed a lowered sCD74/MIF ratio in heart failure patients (17.47±10.09 versus 1.413±0.6244).ConclusionsThese findings suggest that treatment of cardiac myofibroblasts with sCD74 and MIF induces necroptosis, offering new insights into the mechanism of myofibroblast depletion during scar maturation. Preliminary clinical data provided first evidence about a clinical relevance of the sCD74/MIF axis in heart failure, suggesting that these proteins may be a promising target to modulate cardiac remodeling and disease progression in heart failure.
Alternative strategies using conditional probability analysis for the diagnosis of coronary artery disease (CAD) were examined in 93 infarct-free women presenting with chest pain. Another group of 42 consecutive female patients was prospectively analyzed. For this latter group, the physician had access to the pretest and posttest probability of CAD before coronary angiography. These 135 women all underwent stress electrocardiographic, thallium scintigraphic, and coronary angiographic examination. The pretest and posttest probabilities of coronary disease were derived from a computerized Bayesian algorithm. Probability estimates were calculated by the four following hypothetical strategies: SO, in which history, including risk factors, was considered; S 1, in which history and stress electrocardiographic results were considered; S2, in which history and stress electrocardiographic and stress thallium scintigraphic results were considered; and S3, in which history and stress electrocardiographic results were used, but in which stress scintigraphic results were considered only if the poststress probability of CAD was between 10% and 90%, i.e., if a sufficient level of diagnostic certainty could not be obtained with the electrocardiographic results alone. The strategies were compared with respect to accuracy with the coronary angiogram as the standard. For both groups of women, S2 and S3 were found to be the most accurate in predicting the presence or absence of coronary disease (p < .05). However, it was found with use of S3 that more than one-third of the thallium scintigrams could have been avoided without loss of accuracy. It was also found that diagnostic catheterization performed to exclude CAD as a diagnosis could have been avoided in half of the patients without loss of accuracy. Studies in the prospective group of 42 women confirmed that S2 and S3 had the best diagnostic accuracy. We also observed a higher prevalence of angiographically documented coronary disease in this group (48% vs 26% in the first group of 93 women). In this prospectively studied group, there was a smaller proportion of patients with a low probability estimate of CAD (29% of the patients with a probability of .10% in the prospective group vs 58% of the patients in the first group). Our results suggest that the treating physician's prior knowledge of probability estimates reduced the number of unnecessary diagnostic coronary angiographic procedures performed. Circulation 71, No. 3, 535-542, 1985. THE APPLICATION of probability methods to the diagnosis of coronary artery disease (CAD) is an important conceptual advance. IA The validity of probability analysis for diagnosing CAD has already been demonstrated by comparison of the calculated probability of disease with coronary angiographic results.5-10 Another potential application of probability analysis is to
BackgroundIschemic-reperfusion (IR) injury still represents a major concern in clinical transplantation, especially in the era of extreme organ shortage and extended criteria donor organs. In the present study we aimed to investigate the hepatoprotective effects of remote ischemic conditioning (RIC) in a rat model of arterialized orthotopic liver transplantation (OLT).MethodsMale Lewis rats were used (n = 144 / 72 OLT cases; 240–340g) as donors and recipients. Livers were flushed and stored in 4°C HTK-solution for 8h before implantation. Recipients were randomly allocated into three experimental groups: RIC 1, RIC 2, Control. In RIC 1, RIC 2 groups, RIC was applied in the recipient before hepatectomy or after reperfusion (4x5-5min IR via clamping the infrarenal aorta), respectively. Animals were sacrificed at 1, 3, 24, 168h post-reperfusion (n = 6 recipient/group/time point). Hepatocellular injury, graft circulation, serum cytokines, tissue redox-stress and adenosine-triphosphate (ATP) levels have been assessed. Additional markers were analyzed, using Western blotting and reverse-transcription polymerase chain reaction.ResultsRIC 1 group showed significantly (p<0.05) improved portal venous and microcirculation flow as well as velocity. RIC has significantly reduced tissue injury according to the serum levels of transaminases and results of histopathological evaluation. Reduced TUNEL-staining (p<0.01 RIC 1–2 vs. Control) and elevated pBAD/BAD ratio was detected in the RIC groups (p<0.01 RIC 1 vs. Control). Supporting findings were obtained from measurements of serum IL-10 as well as tissue malondialdehyde and ATP levels. Hemoxygenase-1 (HO-1) mRNA-expression was significantly higher in RIC 1 compared to Control (p<0.05 RIC 1 vs. Control).ConclusionThese results suggest that RIC might confer potent protection against the detrimental effects of IR injury including tissue damage, apoptosis, graft circulation, inflammation, tissue energetic status in OLT. HO-1 overexpression might play an orchestrating role in RIC mediated organ protection. An earlier intervention (RIC 1 protocol) was more effective than remote conditioning after graft reperfusion.
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