Search results for "Circulation"
showing 10 items of 1137 documents
Hypoxia-induced dysfunction of rat diaphragm
2004
Contains fulltext : 47331.pdf (Publisher’s version ) (Closed access) Oxidants may play a role in hypoxia-induced respiratory muscle dysfunction. In the present study we hypothesized that hypoxia-induced impairment in diaphragm contractility is associated with elevated peroxynitrite generation. In addition, we hypothesized that strenuous contractility of the diaphragm increases peroxynitrite formation. In vitro force-frequency relationship, isotonic fatigability, and nitrotyrosine levels were assessed under hypoxic (Po(2) approximately 6.5 kPa) and hyperoxic (Po(2) approximately 88.2 kPa) control conditions and also in the presence of authentic peroxynitrite (60 min), ebselen (60 min), and t…
Anatomic and flow dynamic considerations for safe right axillary artery cannulation.
2013
Objectives Neuroprotection is of paramount interest in cardiac surgery. Right axillary artery cannulation is well established in aortic surgery because it significantly improves survival and outcome, but malperfusion of the right brain after direct cannulation has been reported. Anatomically, 4 vessel segments are potentially amenable for cannulation of the subclavian and axillary arteries. Clinical studies vary widely in dissection sites and cannulation techniques. We investigated critical flow dynamics in the right brain caused by arterial inflow after direct cannulation and specified cannulation positions that provide optimal cerebral perfusion. Methods Distances from the lateral margin …
Feasibility of transcatheter aortic valve implantation in patients with coronary heights ≤7 mm: insights from the transcatheter aortic valve implanta…
2018
OBJECTIVES Transcatheter aortic valve implantation (TAVI) in patients with low coronary heights is generally denied but is not impossible. Information about these high-risk procedures is sparse. METHODS Since May 2008, data of more than 3000 patients who had TAVI were prospectively collected in the institutional TAVI Karlsruhe registry. Characteristics, peri- and postoperative outcome of patients with low coronary heights of ≤7 mm were analysed according to the Valve Academic Research Consortium-2. RESULTS Eighty-six patients with an average coronary height of 6.4 ± 1.1 mm (mean age 81.0 ± 5.3 years, logistic EuroSCORE I 19.6 ± 13.3%) were treated. TAVI was performed in 72 transfemoral (83.…
Shedding some light on tricuspid intervention
2021
Background More than 1.6 million Americans have at least moderate to severe valvular tricuspid regurgitation, yet fewer than 8000 tricuspid valve operations are performed annually in the USA. The undertreatment for isolated tricuspid regurgitation might be related to the fact that in the past years no clear guidelines on 'how' and 'when' to treat tricuspid regurgitation were issued. Aims Sarris-Michopoulos and colleagues carried out a meta-analysis with the aim to investigate the role of tricuspid valve repair versus tricuspid valve replacement in patients with isolated tricuspid valve regurgitation. Material and methods Outcomes of patients with first-time surgery for isolated tricuspid va…
Particulate Matter Contamination of Intravenous Antibiotics Aggravates Loss of Functional Capillary Density in Postischemic Striated Muscle
2002
Through the increased use of less expensive and counterfeit medicines, the contamination of parenteral fluids and drugs by particulate matter poses an increasing health hazard worldwide. However, the mechanism of action of such contamination has never been conclusively demonstrated. We have systemically injected the particles contained in three different 1-g preparations of the antibiotic cefotaxime into hamsters and visualized the functional capillary density in striated skin muscle, using intravital fluorescence microscopy. Injection of particles from either of the three preparations did not affect capillary perfusion in normal muscle (n = 3 hamsters, each). However, injection of particle…
GM-CSF expression by human lung microvascular endothelial cells: in vitro and in vivo findings.
2002
Recently, many findings indicate that granulocyte-macrophage colony-stimulating factor (GM-CSF) plays an important role in the pathogenesis of acute and chronic lung diseases. In the present paper, the production of this cytokine in human pulmonary microvascular endothelial cells (HPMEC) is investigated. In an in vitro study, quiescent HPMEC did not express GM-CSF, either at the transcriptional or at the protein level. After activation for 4 h with tumor necrosis factor (TNF)-α (30/300 U/ml), lipopolysaccharide (LPS; 0.1/1 μg/ml), or interleukin (IL)-1β (100 U/ml), a significant release of GM-CSF was measured by enzyme-linked immunosorbent assay, with a time-dependent increase over 72 h. IL…
Observation of ventilation-induced Spo(2) oscillations in pigs: first step to noninvasive detection of cyclic recruitment of atelectasis?
2010
High arterial partial oxygen pressure (Pao(2)) oscillations within the respiratory cycle were described recently in experimental acute lung injury. This phenomenon has been related to cyclic recruitment of atelectasis and varying pulmonary shunt fractions. Noninvasive detection of Spo(2) (oxygen saturation measured by pulse oximetry) as an indicator of cyclic collapse of atelectasis, instead of recording Pao(2) oscillations, could be of clinical interest in critical care. Spo(2) oscillations were recorded continuously in three different cases of lung damage to demonstrate the technical feasibility of this approach. To deduce Pao(2) from Spo(2), a mathematical model of the hemoglobin dissoci…
The murine bronchopulmonary microcirculation in hapten-induced inflammation
2006
ObjectiveThe clinical observation of central bronchial artery hypertrophy in chronic lung inflammation suggests the possibility that the bronchial circulation may also participate in adaptive responses in peripheral lung inflammation.MethodsTo investigate the potential role of the bronchial microcirculation in peripheral lung inflammation, we developed a murine model of lung inflammation using the intratracheal instillation of the peptide-hapten trinitrophenol in presensitized mice.ResultsClinical parameters indicated a peak inflammatory response at 96 hours. Similarly, gross and microscopic evidence of inflammation was observed 96 hours after antigen instillation. Using a forced oscillatio…
Characteristics of coronary microcirculatory function in patients with Takotsubo syndrome.
2017
Background: Takotsubo syndrome (TS) is a recently described cardiac syndrome whose pathogenesis is still unclear. We investigated the characteristics of coronary microcirculatory function in patients with TS through the analysis of the TIMI frame count (TFC) compared to normal subjects and with to subjects with microvascular angina (MA). Methods: We enrolled 71 TS patients (F:M =69:2, mean age of 65.27±9.53 years), 70 controls (F:M =34:36, mean age of 56.63±13.5 years) and 71 patients with MA, (F:M =69:2, mean age of 65.9±9.2 years). The assessment of the microcirculation was carried out through the TFC. Results: microcirculation was significantly altered in patients with TS compared with h…
Extracorporeal circulation and cardiac arrest in an awake patient: a safe approach for single lung pulmonary artery stenting?
2005
We describe the anesthetic concept and approach in a single lung patient scheduled for pulmonary artery stenting due to recurrence of a pulmonary artery sarcoma after left pneumectomy.