Good neurological outcome despite very low regional cerebral oxygen saturation during resuscitation - a prospective preclinical trial in 29 patients

Background Noninvasive regional cerebral oxygen saturation (rSO2) measurement using near-infrared spectroscopy (NIRS) might inform on extent and duration of cerebral hypoxia during cardiopulmonary resuscitation (CPR). This information may be used to guide resuscitation efforts and may carry relevant early prognostic information. Methods We prospectively investigated non-traumatic out-of-hospital cardiac arrest (OHCA) patients on scene. NIRS was started either during CPR or shortly after (<2 min) return of spontaneous circulation (ROSC) by emergency medical service (EMS). Outcome was determined at intensive care unit (ICU) discharge and 6 months after cardiac arrest. Results A total of 29 OHCA patients were included. In 23 patients NIRS was started during CPR and in 6 patients immediately after ROSC. 18 (62.1 %) patients did not reach ROSC. Initial rSO2 during CPR was very low (<50 % in all 23 patients, < 30 % in 19 of 23 patients) with no significant difference between patients achieving ROSC and those who did not. Of five patients with ROSC, in whom NIRS was recorded during CPR, two reached a good six-months outcome (initial rSO2 22 %) and three died during the ICU stay (initial rSO2 15, 16 and 46 %). In six patients with NIRS started immediately after ROSC (<2 min), rSO2 was substantially higher (54–85 %) than in patients during CPR (p = 0.006). Discussion and conclusion Initial frontal brain rSO2 determined by NIRS during CPR was generally very low and recovered rapidly after ROSC. Very low initial rSO2 during CPR was compatible with good neurological outcome in our limited cohort of patients. Further studies are needed to assess in larger cohorts and more detail the implications of very low initial rSO2 during CPR on scene

AntagomiR directed against miR-20a restores functional BMPR2 signalling and prevents vascular remodelling in hypoxia-induced pulmonary hypertension

Aims Dysregulation of the bone morphogenetic protein receptor type 2 (BMPR2) is a hallmark feature that has been described in several forms of pulmonary hypertension. We recently identified the microRNA miR-20a within a highly conserved pathway as a regulator of the expression of BMPR2. To address the pathophysiological relevance of this pathway in vivo, we employed antagomiR-20a and investigated whether specific inhibition of miR-20a could restore functional levels of BMPR2 and, in turn, might prevent pulmonary arterial vascular remodelling. Methods and results For specific inhibition of miR-20a, cholesterol-modified RNA oligonucleotides (antagomiR-20a) were synthesized. The experiments in mice were performed by using the hypoxia-induced mouse model for pulmonary hypertension and animal tissues were analysed for right ventricular hypertrophy and pulmonary arterial vascular remodelling. Treatment with antagomiR-20a enhanced the expression levels of BMPR2 in lung tissues; moreover, antagomiR-20a significantly reduced wall thickness and luminal occlusion of small pulmonary arteries and reduced right ventricular hypertrophy. To assess BMPR2 signalling and proliferation, we performed in vitro experiments with human pulmonary arterial smooth muscle cells (HPASMCs). Transfection of HPASMCs with antagomiR-20a resulted in activation of downstream targets of BMPR2 showing increased activation of Id-1 and Id-2. Proliferation of HPASMCs was found to be reduced upon transfection with antagomiR-20a. Conclusion This is the first report showing that miR-20a can be specifically targeted in an in vivo model for pulmonary hypertension. Our data emphasize that treatment with antagomiR-20a restores functional levels of BMPR2 in pulmonary arteries and prevents the development of vascular remodellin

Pre-hospital cerebral oxygen saturation measurement in cardiac arrest patients under particular consideration of „Targeted Temperature Management“

Im Rahmen dieser Arbeit wurde die regionale Hirnsauerstoffsättigung (rSO2) als möglicher Parameter für die Vorhersage des neurologischen Outcomes unter und im Anschluss an eine kardiopulmonale Reanimation (CPR) gemessen. Besonders berücksichtigt wurde hierbei das „Targeted Temperature Management“ (TTM), dessen Zieltemperatur bei 33°C lag. Die rSO2 erwies sich in vorherigen Studien als Parameter, der in der Lage zu sein scheint, veränderte zerebrale Perfusion und Oxygenierung darzustellen. Die Messung der rSO2 erfolgte mittels Nah- Infrarot-Spektroskopie (NIRS) in einer Tiefe von ca. 2,5 cm, mit deren Hilfe das Verhältnis von oxygeniertem zu desoxygeniertem Hämoglobin bestimmt wird. Die dargestellten Werte entsprechen einer gemischt arterio-venösen Sauerstoffsättigung. Zentraler Bestandteil der Dissertation war die eigenständige Durchführung der NIRS- Messungen auf dem Notarzteinsatzfahrzeug (NEF) 2505 der Berliner Feuerwehr. In die vorliegende Studie konnten 29 Patienten eingeschlossen werden, bei denen die rSO2 im präklinischen Umfeld gemessen wurde. Der Beginn der kontinuierlichen Messung erfolgte unter laufender Reanimation bzw. maximal 2 Minuten nach Wiedereinsetzen eines Spontankreislaufes (ROSC) und wurde nach dem TTM beendet. Parallel wurden das Alter, das Geschlecht, der initiale Rhythmus, die verabreichte Adrenalindosis, die Dauer der Reanimation, die Respiratorstunden, der APACHE II Score und die Aufenthaltsdauer erhoben. Das neurologische Outcome wurde bei Entlassung mittels der „Cerebral Performance Category“ (CPC) klassifiziert. Das Gesamtkollektiv (n=29) wurde retrospektiv in 3 Gruppen unterteilt (1. gutes neurologisches Ergebnis = CPC 1-2; 3 Patienten – 2. schlechtes neurologisches Ergebnis = CPC 3-5 bei 8 Patienten – 3. nie ROSC = CPC 5 bei 18 Patienten). In der Gruppe mit einem CPC 1-2 war die rSO2 zu Beginn der Messung im Median mit 23% (22-52%) vs. 19% (15-42%) höher. Die durchschnittliche rSO2 über den gesamten Verlauf der Messung (n=11) ist mit 71% (70-73%) vs. 63% (54-73%) ebenfalls deutlich höher bei Patienten mit gutem Outcome. Bei den Patienten ohne ROSC (n=18) lag der Median der rSO2 bei 16% (IQR 15-29). Zwei der Patienten, bei denen ein CPC von 1-2 bei der Entlassung vorlag, wurden unter Reanimation eingeschlossen. Deren initia-le rSO2 lagen bei 22% und 23%. In der Vergleichsgruppe (CPC 3-5) konnten 3 Patienten eingeschlossen werden. Deren initiale rSO2 Werte lagen bei 15%, 16% und 46%. Patienten mit gutem Outcome hatten initial höhere rSO2 Werte und lagen auch im Verlauf bei deutlich höheren rSO2 Werten. Ein Überleben mit CPC 1-2 scheint auch bei initial niedrigen rSO2 Werten möglich. Die initialen rSO2 Werte sind daher wahrscheinlich keine guten Prädiktoren für das Outcome. Aufgrund der zahlreichen Einflussfaktoren auf die rSO2 und der kleinen Patientenzahl sind jedoch weitere Untersuchungen an diesen Kollektiven nötig.In the context of the present work the regional cerebral oxygen saturation (rSO2) was measured during and subsequent to a cardiopulmonary resuscitation (CPR) as parameter potentially predicting the neurological outcome. In particular consideration was the ‘Targeted Temperature Management’ (TTM) with a target temperature of 33°C in this study. Previous studies showed rSO2 as parameter having the ability to represent changed cerebral perfusion and oxygenation. Regional cerebral oxygen saturation was measured by use of near infrared spectroscopy (NIRS) determining with infrared light the proportion of oxygenated to deoxygenated hemoglobin in a depth of about 2.5cm. The depicted values correspond to an arterio-venous oxygen saturation. A key component of this dissertation was the independent NIRS measurement on the emergency doctor´s vehicle 2505 of the Berlin fire department. In the framework of this study 29 patients with pre-hospital measurement of rSO2 were included. Continuous measurement was initiated under current reanimation or at the maximum two minutes after return of spontaneous circulation (ROSC) and was terminated at the end of therapeutic TTM. Simultaneously collected were the progress of body temperature, age, sex, initial rhythm, administered adrenalin dose, length of reanimation, hours on respirator, APACHE II score and the length of stay. At discharge neurological outcome was classified by ‘cerebral performance category’ (CPC). Retrospectively all patients (n=29) were divided into three groups (1. – good neurological out-come = CPC 1-2, three patients; 2. – bad neurological outcome = CPC 3-5, eight patients; 3. – no ROSC = CPC 5, 18 patients). Group 1 with good CPC (1-2) showed a rSO2 median of 23% (22 – 52%) being higher than that of the other group with 19% (15 – 42%). Average of rSO2 measured across the complete process (n=11) also was distinctly higher in patients with good outcome (71% (70 – 73%) vs. 63% (54 – 73%)). Patients with no ROSC (n=18) had a rSO2 median of 16.5% (IQR 15 – 29%). Two patients with CPC at discharge of 1-2 were included under reanimation. Their initial rSO2 were at 22% and 23%. In the comparison group (CPC 3-5) three patients could be included under CPR. Their initial values were at 15%, 16% and 46%. Patients with good outcome showed higher initial rSO2 values and also showed higher rSO2 values during the process. It appears that survival is possible with low initial rSO2 values. Probably the initial rSO2 values are not good outcome predictors. Due to the numerous factors influencing rSO2 and the small number of patients in this study further investigations of such collectives are necessary

The hypoxia-induced microRNA-130a controls pulmonary smooth muscle cell proliferation by directly targeting CDKN1A

Excessive proliferation of human pulmonary artery smooth muscle cells (HPASMC) is one of the major factors that trigger vascular remodeling in hypoxia-induced pulmonary hypertension. Several studies have implicated that hypoxia inhibits the tumor suppressor p21 (CDKN1A). However, the precise mechanism is unknown. The mouse model of hypoxia-induced PH and in vitro experiments were used to assess the impact of microRNAs (miRNAs) on the expression of CDKN1A. In these experiments, the miRNA family miR-130 was identified to regulate the expression of CDKN1A. Transfection of HPASMC with miR-130 decreased the expression of CDKN1A and, in turn, significantly increased smooth muscle proliferation. Conversely, inhibition of miR-130 by anti-miRs and seed blockers increased the expression of CDKN1A. Reporter gene analysis proved a direct miR-130-CDKN1A target interaction. Exposure of HPASMC to hypoxia was found to induce the expression of miR-130 with concomitant decrease of CDKN1A. These findings were confirmed in the mouse model of hypoxia-induced pulmonary hypertension showing that the use of seed blockers against miR-130 restored the expression of CDKN1A. These data suggest that miRNA family miR-130 plays an important role in the repression of CDKN1A by hypoxia. miR-130 enhances hypoxia-induced smooth muscle proliferation and might be involved in the development of right ventricular hypertrophy and vascular remodeling in pulmonary hypertension

Histone deacetylase/acetylase activity in total synovial tissue derived from rheumatoid arthritis and osteoarthritis patients

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disorder of unknown origin. Histone deacetylase (HDA) activity is considered to play a major role in the transcriptional regulation of proinflammatory genes. We undertook this study to investigate the balance of histone acetylase and HDA activity in synovial tissue from RA patients compared with that from patients with osteoarthritis (OA) and normal controls. METHODS: Activity of histone acetylases and HDAs was measured in nuclear extracts of total synovial tissue samples, which were obtained from RA and OA patients undergoing surgical joint replacement, and compared with the activity in synovial tissues from patients without arthritis. Tissue expression of HDAs 1 and 2 was quantified by Western blotting. In addition, immunohistochemistry was performed for HDA-2. RESULTS: Mean+/-SEM HDA activity in synovial tissue samples derived from patients with RA was measured as 1.5+/-0.3 micromoles/microg, whereas the activity levels in OA (3.2+/-0.7 micromoles/microg) and normal (7.1+/-4.2 micromoles/microg) synovial tissue samples were significantly higher. Histone acetylase activity reached similar levels in RA and OA tissues and in normal tissues. The ratio of HDA activity to histone acetylase activity in RA synovial tissue was significantly reduced (12+/-2%) compared with that in OA synovial tissue (26+/-3%). The activity ratio in normal control samples was arbitrarily set at 100+/-40%. In addition, the tissue expression of HDA-1 and HDA-2 proteins was clearly lower in RA samples than in OA samples. CONCLUSION: The balance of histone acetylase/HDA activities is strongly shifted toward histone hyperacetylation in patients with RA. These results offer novel molecular insights into the pathogenesis of the disease that might be relevant to the development of future therapeutic approaches

AntagomiR directed against miR-20a restores functional BMPR2 signalling and prevents vascular remodelling in hypoxia-induced pulmonary hypertension

AimsDysregulation of the bone morphogenetic protein receptor type 2 (BMPR2) is a hallmark feature that has been described in several forms of pulmonary hypertension. We recently identified the microRNA miR-20a within a highly conserved pathway as a regulator of the expression of BMPR2. To address the pathophysiological relevance of this pathway in vivo, we employed antagomiR-20a and investigated whether specific inhibition of miR-20a could restore functional levels of BMPR2 and, in turn, might prevent pulmonary arterial vascular remodelling.Methods and resultsFor specific inhibition of miR-20a, cholesterol-modified RNA oligonucleotides (antagomiR-20a) were synthesized. The experiments in mice were performed by using the hypoxia-induced mouse model for pulmonary hypertension and animal tissues were analysed for right ventricular hypertrophy and pulmonary arterial vascular remodelling. Treatment with antagomiR-20a enhanced the expression levels of BMPR2 in lung tissues; moreover, antagomiR-20a significantly reduced wall thickness and luminal occlusion of small pulmonary arteries and reduced right ventricular hypertrophy. To assess BMPR2 signalling and proliferation, we performed in vitro experiments with human pulmonary arterial smooth muscle cells (HPASMCs). Transfection of HPASMCs with antagomiR-20a resulted in activation of downstream targets of BMPR2 showing increased activation of Id-1 and Id-2. Proliferation of HPASMCs was found to be reduced upon transfection with antagomiR-20a.ConclusionThis is the first report showing that miR-20a can be specifically targeted in an in vivo model for pulmonary hypertension. Our data emphasize that treatment with antagomiR-20a restores functional levels of BMPR2 in pulmonary arteries and prevents the development of vascular remodelling