Search results for "circulatory and respiratory physiology"
showing 10 items of 329 documents
Influence of PEEP on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome.
2013
High levels of positive end-expiratory pressure (PEEP), as part of the treatment in patients with acute respiratory distress syndrome (ARDS), may prevent alveolar collapse and maintain oxygenation. PEEP potentially reduces cerebral venous return, increases intracranial blood volume, and may, therefore, affect cerebral blood flow (CBF) and cerebrovascular autoregulation (AR). This study investigates the effect of PEEP on CBF and AR in patients with respiratory failure.CBF velocity was measured using transcranial doppler and correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx0.3 indicates impaired AR). Mx was measured at lower PEEP levels and after i…
Interaction between Angiotensin Type 1, Type 2, and Mas Receptors to Regulate Adult Neurogenesis in the Brain Ventricular–Subventricular Zone
2019
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Nitric oxide modulates cerebral blood flow stimulation by acetazolamide in the rat cortex: a laser Doppler scanning study
2001
Abstract The involvement of nitric oxide (NO) in cerebral blood flow (CBF) stimulation by acetazolamide was studied in anaesthetised, mechanically ventilated Wistar rats. CBF was monitored by laser Doppler scanning. Acetazolamide induced a long-lasting significant rCBF-increase. Application of N G -Nitro- l -arginine (L-NNA), an inhibitor of all NO synthetases (NOS), prevented CBF stimulation by acetazolamide. Continuous infusion of the exogenous NO donor SIN-1 (3-morpholinosydnonimine) suppressed L-NNA induced increases of mean arterial blood pressure without effect on rCBF in comparison to baseline. Additional acetazolamide injection then again caused a significant increase of rCBF in spi…
The Cerebral Thrombin System Is Activated after Intracerebral Hemorrhage and Contributes to Secondary Lesion Growth and Poor Neurological Outcome in …
2020
With increasing evidence for the existence of a cerebral thrombin system, coagulation factor IIa (thrombin) is suspected to influence the pathogenesis of secondary injury progression after intracerebral hemorrhage (ICH). We hypothesized that mechanisms associated with local volume expansion after ICH, rather than blood constituents, activate the cerebral thrombin system and are responsible for detrimental neurological outcome. To test this hypothesis, we examine the local thrombin expression after ICH in a C57BL/6N mouse model in the presence and absence of blood constituents. ICH was established using stereotaxic orthotopic injection of utologous blood (
Epidemiology of multiple congenital anomalies in Europe : A EUROCAT population-based registry study
2014
BACKGROUND: This study describes the prevalence, associated anomalies, and demographic characteristics of cases of multiple congenital anomalies (MCA) in 19 population-based European registries (EUROCAT) covering 959,446 births in 2004 and 2010.METHODS: EUROCAT implemented a computer algorithm for classification of congenital anomaly cases followed by manual review of potential MCA cases by geneticists. MCA cases are defined as cases with two or more major anomalies of different organ systems, excluding sequences, chromosomal and monogenic syndromes.RESULTS: The combination of an epidemiological and clinical approach for classification of cases has improved the quality and accuracy of the M…
Bruce/apollon promotes hippocampal neuron survival and is downregulated by kainic acid
2005
Prolonged or excess stimulation of excitatory amino acid receptors leads to seizures and the induction of excitotoxic nerve cell injury. Kainic acid acting on glutamate receptors produces degeneration of vulnerable neurons in parts of the hippocampus and amygdala, but the exact mechanisms are not fully understood. We have here investigated whether the anti-apoptotic protein Bruce is involved in kainic acid-induced neurodegeneration. In the rat hippocampus and cortex, Bruce was exclusively expressed by neurons. The levels of Bruce were rapidly downregulated by kainic acid in hippocampal neurons as shown both in vivo and in cell culture. Caspase-3 was activated in neurons exhibiting low level…
Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol…
2017
Background Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multice…
Basic cardiovascular variability signals: mutual directed interactions explored in the information domain.
2017
The study of short-term cardiovascular interactions is classically performed through the bivariate analysis of the interactions between the beat-to-beat variability of heart period (RR interval from the ECG) and systolic blood pressure (SBP). Recent progress in the development of multivariate time series analysis methods is making it possible to explore how directed interactions between two signals change in the context of networks including other coupled signals. Exploiting these advances, the present study aims at assessing directional cardiovascular interactions among the basic variability signals of RR, SBP and diastolic blood pressure (DBP), using an approach which allows direct compar…
Monitoring White Blood Cell Mitochondrial Aldehyde Dehydrogenase Activity: Implications for Nitrate Therapy in Humans
2009
Recent animal data suggest that reduced lipoic acid (LA) prevents oxidative inhibition of the nitrate bioactivating enzyme, the mitochondrial aldehyde dehydrogenase (ALDH-2), and that pentaerythritol tetranitrate (PETN) does not induce nitrate tolerance because of its intrinsic antioxidative properties, thereby preserving ALDH-2 activity. We sought to determine whether ALDH-2 activity in circulating white blood cells (WBCs) can be used to monitor nitrate tolerance and whether LA can prevent nitroglycerin tachyphylaxis in humans. Eight healthy male volunteers received, in randomized order, a single dose of glyceryl trinitrate (GTN; 0.8 mg), PETN (80 mg), or GTN plus LA (600 mg) orally. GTN (…
Circulating neprilysin hypothesis: A new opportunity for sacubitril/valsartan in patients with heart failure and preserved ejection fraction?
2021
BackgroundCirculating Neprilysin (sNEP) has emerged as a potential prognostic biomarker in heart failure (HF). In PARAGON-HF benefit of sacubitril/valsartan was only observed in patients with left ventricular ejection fraction (LVEF) ≤57%. We aimed to assess the prognostic value of sNEP in outpatients with HF and LVEF >57%, in comparison with patients with LVEF ≤57%.MethodsConsecutive HF outpatients were included from May-2006 to February-2016. The primary endpoint was the composite of all-cause death or HF hospitalization and the main secondary endpoint was the composite of cardiovascular death or HF hospitalization. For the later competing risk methods were used.ResultssNEP was measure…