Long-Term Efficacy and Safety of Left Atrial Appendage Closure Procedures.

The aim of the present single-center, nonrandomized, retrospective study was to assess the safety and long-term efficacy of percutaneous left atrial appendage closure (LAAC) procedures and to compare the different LAAC devices and therapeutic regimes in this respect.Medical data of 136 patients (pts) (mean age, 72.5 ± 7.6 years; score for atrial fibrillation stroke risk estimation [CHA2DS2-VASc], 4.6 ± 1.6; and score for estimation of major bleeding risk for patients on anticoagulant therapy [HAS-BLED], 2.6 ± 0.9) who underwent percutaneous LAAC procedures in Gottsegen National Cardiovascular Center from January 2010 to January 2020 were analyzed.The rates of outpatient cardiac mortality, ischemic brain event, and major bleeding were 3.8, 1, and 1.9/100 pt years, respectively. The rate of successful device deployment was 96.4%. There was one case of procedural mortality (0.7%), one case of device dislocation (0.7%), one case of ischemic stroke (0.7%), and one case of myocardial infarction (0.7%). Two cases of pericardial tamponades (1.5%) and four cases of major femoral complications (3%) occurred. Although the implantation success of different occluder types was similar, significant differences were found concerning procedural characteristics. Patients on single antiplatelet therapy (SAPT) in the first 3 months after the LAAC procedure did not suffer from stroke or embolic events.The present study confirmed the safety and effectivity of percutaneous LAAC. Robust relative stroke risk reduction and less pronounced but significant bleeding risk reduction were observed. Device implantation success was high. The perioperative complication rate was relatively low. The results of long-term observations regarding ischemic events confirmed the safety of using a simplified antithrombotic regime after LAAC in pts with high bleeding risk.

Comparison of different preparation techniques of dried blood spot quality controls in newborn screening for congenital adrenal hyperplasia.

In newborn screening, samples suspected for congenital adrenal hyperplasia (CAH), a potentially lethal inborn error of steroid biosynthesis, need to be confirmed using liquid chromatography-tandem mass spectrometry. Daily quality controls (QCs) for the 2nd-tier CAH assay are not commercially available and are therefore generally prepared within the laboratory. For the first time, we aimed to compare five different QC preparation approaches used in routine diagnostics for CAH on the concentrations of cortisol, 21-deoxycortisol, 11-deoxycortisol, 4-androstenedione and 17-hydroxyprogesterone in dried blood spots. The techniques from Prep1 to Prep5 were tested at two analyte concentrations by spiking aliquots of a steroid-depleted blood, derived from washed erythrocyte suspension and steroid-depleted serum. The preparation processes differed in the sequence of the preparation steps and whether freeze-thaw cycles were used to facilitate blood homogeneity. The five types of dried blood spot QCs were assayed and quantitated in duplicate on five different days using a single calibration row per day. Inter-assay variations less than 15% and concentrations within ±15% of the nominal values were considered acceptable. Results obtained by means of the four dried blood spot QC preparation techniques (Prep1, Prep2, Prep4 and Prep5) were statistically similar and remained within the ±15% ranges in terms of both reproducibility and nominal values. However, concentration results for Prep3 (spiking prior to three freeze-thaw cycles) were significantly lower than the nominal values in this setting, with differences exceeding the ±15% range in many cases despite acceptable inter-assay variations. These findings have implications for the in-house preparation of QC samples in laboratory developed tests for CAH, including 2nd-tier assays in newborn screening.

Storage stability of five steroids and in dried blood spots for newborn screening and retrospective diagnosis of congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is a severe inherited disorder of cortisol biosynthesis that is potentially lethal or can seriously affect quality of life. For the first time, we aimed to assess the stability of 21-deoxycortisol (21Deox), 11-deoxycortisol (11Deox), 4-androstenedione (4AD), 17-hydroxyprogesterone (17OHP) and cortisol (Cort), diagnostic for CAH, in dried blood spots (DBSs) during a 1 year storage at different temperatures. Spiked DBS samples were stored at room temperature, 4 °C, -20 °C or -70 °C, respectively and analyzed in triplicates using liquid chromatography-tandem mass spectrometry at Weeks 0, 1, 2, 3 and 4, Month 6 and Year 1. Analyte levels within ±15% vs the baseline were considered stable. Our observations show that 21Deox, 4AD and 17OHP were not significantly changed for 1 year even at room temperature at either analyte levels. In contrast, Cort required storage at 4 °C, -20 °C or -70 °C for long-term stability, being significantly decreased at room temperature from Month 6 (p<0.01) in both the 30(60) nM and the 90(180) nM samples. 11Deox was significantly decreased at room temperature at Year 1 (p<0.01) and only in the 30(60) nM samples. Thus, all biomarkers were stable for up to 1 year at 4 °C, -20 °C or -70 °C and at least for 4 weeks at room temperature. These findings have implications for analyses of stored DBS samples in 2nd-tier assays in newborn screening and for retrospective CAH studies.

Survival and differentiation of neuroectodermal cells with stem cell properties at different oxygen levels.

Freeze-lesioned regions of the forebrain cortex provide adequate environment for growth of non-differentiated neural progenitors, but do not support their neuron formation. Reduced oxygen supply, among numerous factors, was suspected to impair neuronal cell fate commitment. In the present study, proliferation and differentiation of neural stem/progenitor cells were investigated at different oxygen levels both in vitro and in vivo. Low (1% atmospheric) oxygen supply did not affect the in vitro viability and proliferation of stem cells or the transcription of "stemness" genes but impaired the viability of committed neuronal progenitors and the expression of proneural and neuronal genes. Consequently, the rate of in vitro neuron formation was markedly reduced under hypoxic conditions. In vivo, neural stem/progenitor cells survived and proliferated in freeze-lesioned adult mouse forebrains, but did not develop into neurons. Hypoperfusion-caused hypoxia in lesioned cortices was partially corrected by hyperbaric oxygen treatment (HBOT). HBOT, while reduced the rate of cell proliferation at the lesion site, resulted in sporadic neuron formation from implanted neural stem cells. The data indicate that in hypoxic brain areas, neural stem cells survive and proliferate, but neural tissue-type differentiation can not proceed. Oxygenation renders the damaged brain areas more permissive for tissue-type differentiation and may help the integration of neural stem/progenitor cells.

Studies on the use of NE-4C embryonic neuroectodermal stem cells for targeting brain tumour.

Neural stem cells were suggested to migrate to and invade intracranial gliomas. In the presented studies, interactions of NE-4C embryonic neural stem cells were investigated with C6 and Gl261, LL and U87, glioblastoma cells or with primary astrocytes. Glioma-derived humoral factors did not influence the proliferation of stem cells. NE-4C-derived humoral factors did not alter the proliferation of Gl261 and U87 cells, but increased the mitotic activity of C6 cells and that of astrocytes. In chimera-aggregates, all types of glioma cells co-aggregated with astrocytes, but most of them segregated from stem cells. Complete intercalation of stem and tumour cells was detected only in chimera-aggregates of Gl261 glioma and NE-4C cells. If mixed suspensions of NE-4C and Gl261 cells were injected into the brain, stem cells survived and grew inside the tumour mass. NE-4C stem cells, however, did not migrate towards the tumour, if implanted near to Gl261 tumours established in the adult mouse forebrain. The observations indicate that not all types of stem cells could be used for targeting all sorts of brain tumours.