58 research outputs found
Effects of the sodium channel modulator BDF 9148 on the developing rabbit heart after myocardial stunning
No full textImpaired Exercise Tolerance after Repair of Tetralogy of Fallot—Insights from Real-Time Cardiovascular Magnetic Resonance Imaging
No full textObjectives: Surgical correction of tetralogy of Fallot (cTOF) frequently results in residual pulmonary valve stenosis/regurgitation and impaired right ventricular (RV) function. Reduced capacity in cardiopulmonary exercise testing (CPET) in cTOF patients, however, cannot entirely be explained by these findings. The present study sought to assess biventricular cardiac function during exercise using a comprehensive CPET and real-time cardiovascular magnetic resonance exercise testing (CMR-ET) protocol. Methods: A total of 33 cTOF patients (age 35.6 + 11.3 years) and 33 matched healthy controls (age 34.4 +11.9 years) underwent CPET and CMR-ET. Real-time SSFP and phase contrast sequences were obtained during supine bicycle in scanner CMR-ET at 50, 70, and 90 W. RV and LV volumetry and flow quantification of the pulmonary trunk (Qp) were performed. Correlation between CPET and CMR-ET parameters was investigated using Spearman’s rank test. Results: Exercise capacity on CPET was significantly lower in cTOF than in healthy controls. With incremental exercise levels on CMR-ET, cTOF patients failed to recruit both RV and LV functions and Qp (Table 1). Correlation analysis revealed higher CPET values in those cTOF patients with higher Qp (Qp 90 W vs. VE/VCO2%: r = −0.519, p < 0.05), higher LV EDVi (LV EDVi at 50 W vs. VO2% r = 0.452, p < 0.05) and less change in LV EF (LV-EF at 90 W vs. W % r = −0.463, p < 0.05). No correlation was found with RV EF. Significant RV–LV interaction was observed at 70 W CMR-ET (correlation of RV and LF EF r = 0.52, p < 0.05). Conclusion: Compared with healthy controls, cTOF patients displayed impaired exercise capacity due to a lack in recruitment of both RV function and pulmonary blood flow but also of LV function. RV and LV functions during exercise showed significant interdependence. CMR-ET may be a helpful tool in the assessment of cardiac function in cTOF patients
Bronchoconstriction in nonhuman primates: a species comparison
No full textBronchoconstriction is a characteristic symptom of various chronic obstructive respiratory diseases such as chronic obstructive pulmonary disease and asthma. Precision-cut lung slices (PCLS) are a suitable ex vivo model to study physiological mechanisms of bronchoconstriction in different species. In the present study, we established an ex vivo model of bronchoconstriction in nonhuman primates (NHPs). PCLS prepared from common marmosets, cynomolgus macaques, rhesus macaques, and anubis baboons were stimulated with increasing concentrations of representative bronchoconstrictors: methacholine, histamine, serotonin, leukotriene D
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(LTD
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), U46619, and endothelin-1. Alterations in the airway caliber were measured and compared with previously published data from rodents, guinea pigs, and humans. Methacholine induced maximal airway constriction, varying between 74 and 88% in all NHP species, whereas serotonin was ineffective. Histamine induced maximal bronchoconstriction of 77 to 90% in rhesus macaques, cynomolgus macaques, and baboons and a lesser constriction of 53% in marmosets. LTD
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was ineffective in marmosets and rhesus macaques but induced a maximum constriction of 44 to 49% in cynomolgus macaques and baboons. U46619 and endothelin-1 caused airway constriction in all NHP species, with maximum constrictions of 65 to 91% and 70 to 81%, respectively. In conclusion, PCLS from NHPs represent a valuable ex vivo model for studying bronchoconstriction. All NHPs respond to mediators relevant to human airway disorders such as methacholine, histamine, U46619, and endothelin-1 and are insensitive to the rodent mast cell product serotonin. Only PCLS from cynomolgus macaques and baboons, however, responded also to leukotrienes, suggesting that among all compared species, these two NHPs resemble the human airway mechanisms best
Glucocorticoids potentiate IL-6-induced SP-B expression in H441 cells by enhancing the JAK-STAT signaling pathway
No full textLadenburger A, Seehase M, Kramer BW, Thomas W, Wirbelauer J, Speer CP, Kunzmann S. Glucocorticoids potentiate IL-6-induced SP-B expression in H441 cells by enhancing the JAK-STAT signaling pathway. Am J Physiol Lung Cell Mol Physiol 299: L578-L584, 2010. First published August 6, 2010; doi:10.1152/ajplung.00055.2010.-The respiratory distress syndrome (RDS) contributes to perinatal morbidity and mortality associated with preterm birth. Surfactant protein B (SP-B) is decreased in RDS. Both maternal antenatal steroid administration and chorioamnionitis reduce the incidence and severity of RDS. An important mediator in chorioamnionitis is IL-6 using the JAK-STAT signaling pathway for signal transduction. We hypothesized that the steroids, betamethasone (BTM) and dexamethasone (DXM), and IL-6 had synergistic effects on SP-B gene expression and STAT3 phosphorylation in H441 cells. DXM and BTM increased SP-B mRNA levels by 16.5 (13.3)-fold and IL-6 alone by 2.3-fold. After 48-h exposure of cells to DXM or BTM, IL-6 caused a significantly greater increase in SP-B mRNA levels (28.1-fold) than IL-6 or glucocorticoids alone. Whereas IL-6 stimulated tyrosine phosphorylation of STAT3 in a time-and dose-dependent way, DXM and BTM had no effect on STAT3 phosphorylation. Both DXM and BTM could potentiate IL-6-induced phosphorylation of STAT3. The synergism of glucocorticoids and IL-6 on SP-B gene expression and the effect of glucocorticoids on IL-6-induced STAT3 phosphorylation could be blocked by a JAK inhibitor. Expression level analysis showed that glucocorticoids increased the expression of the IL-6-binding alpha-subunit receptor (IL-6R) on mRNA and protein level. Our findings could represent an example of a pulmonary regulation system in which one role of glucocorticoids is to increase the effect of a cytokine by upregulation of its receptor. The described in vitro interaction of IL-6 and glucocorticoids could help explain the clinical observation that prenatal inflammation in preterm babies with antenatal steroid administration can attenuate severity of RDS
Abstract OT2-05-02: A phase II study of metronomic daily oral vinorelbine as first-line chemotherapy in advanced/metastatic hormone receptor positive (HR+) / human epidermal growth factor receptor 2 negative (HER2-) breast cancer resistant to endocrine therapy - VinoMetro
No full textAbstract
Background
Chemotherapy (CTx) is a cornerstone in HR+/HER2- advanced/metastatic breast cancer (a/mBC) after failure of endocrine treatment. In this indication, vinorelbine (VRL) is a well-established cytotoxic drug. There is a high medical need for new options that prolong the time between endocrine failure and intensive CTx, which is commonly associated with impaired quality of life and serious side effects. Metronomic CTx was shown to induce disease control in a/mBC with a favorable safety profile. This innovative approach involving continuous daily dosing of oral VRL, which could provide anti-angiogenic and immune-modulatory properties, has not been investigated so far in this indication.
Trial Design
VinoMetro is an open-label, single-arm, phase II study (Simon two-stage minimax) of metronomic daily oral VRL (30 mg/day) as first-line CTx. The study involves strict safety monitoring with an initial safety run-in. It is accompanied by a steering committee and supervised by an independent data safety and monitoring board (DSMB). The main objectives are to estimate efficacy in terms of clinical benefit rate after 24 weeks of treatment (primary endpoint) and the progression-free survival, amongst others, as well as the assessment of safety and quality of life. Patients with HR+/HER2- a/mBC having failed or being no candidate for endocrine therapy (targeted combinations allowed) and being naïve to palliative CTx are eligible, if they exhibit ECOG 0-1. The main exclusion criteria are prior vinca-alkaloids, aggressive disease requiring combination CTx and CNS involvement.
Until 2017-05-31, 7 patients were enrolled. It is planned to include 45 (39 evaluable) patients at 8 German sites until 09/2018. Scheduled completion date is 09/2019. Two interim analyses are planned (first analysis: safety evaluation based on the 10 initial patients with predefined stopping rules). Depending on recruitment, it is planned to include the interim safety data in the congress presentation.
VinoMetro is an investigator initiated trial (NCT03007992) sponsored by the University Medical Centre of Johannes Gutenberg-University Mainz, Germany, and supported by an unrestricted grant provided by Pierre Fabre Pharma GmbH (Freiburg, Germany).
Citation Format: Schmidt M, Decker T, Fehm T, Fuxius S, Harbeck N, Juhasz-Böss I, Thomssen C, Seehase M, Schollenberger L, Ruckes C, Möbus V. A phase II study of metronomic daily oral vinorelbine as first-line chemotherapy in advanced/metastatic hormone receptor positive (HR+) / human epidermal growth factor receptor 2 negative (HER2-) breast cancer resistant to endocrine therapy - VinoMetro [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-05-02.</jats:p
3D Real-Time Echocardiography Combined with Mini Pressure Wire Generate Reliable Pressure-Volume Loops in Small Hearts
No full textBACKGROUND:
Pressure-volume loops (PVL) provide vital information regarding ventricular performance and pathophysiology in cardiac disease. Unfortunately, acquisition of PVL by conductance technology is not feasible in neonates and small children due to the available human catheter size and resulting invasiveness. The aim of the study was to validate the accuracy of PVL in small hearts using volume data obtained by real-time three-dimensional echocardiography (3DE) and simultaneously acquired pressure data.
METHODS:
In 17 piglets (weight range: 3.6–8.0 kg) left ventricular PVL were generated by 3DE and simultaneous recordings of ventricular pressure using a mini pressure wire (PVL3D). PVL3D were compared to conductance catheter measurements (PVLCond) under various hemodynamic conditions (baseline, alpha-adrenergic stimulation with phenylephrine, beta-adrenoreceptor-blockage using esmolol). In order to validate the accuracy of 3D volumetric data, cardiac magnetic resonance imaging (CMR) was performed in another 8 piglets.
RESULTS:
Correlation between CMR- and 3DE-derived volumes was good (enddiastolic volume: mean bias -0.03ml ±1.34ml). Computation of PVL3D in small hearts was feasible and comparable to results obtained by conductance technology. Bland-Altman analysis showed a low bias between PVL3D and PVLCond. Systolic and diastolic parameters were closely associated (Intraclass-Correlation Coefficient for: systolic myocardial elastance 0.95, arterial elastance 0.93, diastolic relaxation constant tau 0.90, indexed end-diastolic volume 0.98). Hemodynamic changes under different conditions were well detected by both methods (ICC 0.82 to 0.98). Inter- and intra-observer coefficients of variation were below 5% for all parameters.
CONCLUSIONS:
PVL3D generated from 3DE combined with mini pressure wire represent a novel, feasible and reliable method to assess different hemodynamic conditions of cardiac function in hearts comparable to neonate and infant size. This methodology may be integrated into clinical practice and cardiac catheterization programs and has the capability to contribute to clinical decision making even in small hearts
Ilse Seehase and Dieter Endler: Roman im Gespräch. Beiträge aus sechs sozialistischen Ländern
No full textHalle/Leipzig: Mitteldeutscher Verlag, 1980. 392 p., 12 M
LPS-induced lung inflammation in marmoset monkeys - an acute model for anti-inflammatory drug testing.
No full textIncreasing incidence and substantial morbidity and mortality of respiratory diseases requires the development of new human-specific anti-inflammatory and disease-modifying therapeutics. Therefore, new predictive animal models that closely reflect human lung pathology are needed. In the current study, a tiered acute lipopolysaccharide (LPS)-induced inflammation model was established in marmoset monkeys (Callithrix jacchus) to reflect crucial features of inflammatory lung diseases. Firstly, in an ex vivo approach marmoset and, for the purposes of comparison, human precision-cut lung slices (PCLS) were stimulated with LPS in the presence or absence of the phosphodiesterase-4 (PDE4) inhibitor roflumilast. Pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α) and macrophage inflammatory protein-1 beta (MIP-1β) were measured. The corticosteroid dexamethasone was used as treatment control. Secondly, in an in vivo approach marmosets were pre-treated with roflumilast or dexamethasone and unilaterally challenged with LPS. Ipsilateral bronchoalveolar lavage (BAL) was conducted 18 hours after LPS challenge. BAL fluid was processed and analyzed for neutrophils, TNF-α, and MIP-1β. TNF-α release in marmoset PCLS correlated significantly with human PCLS. Roflumilast treatment significantly reduced TNF-α secretion ex vivo in both species, with comparable half maximal inhibitory concentration (IC(50)). LPS instillation into marmoset lungs caused a profound inflammation as shown by neutrophilic influx and increased TNF-α and MIP-1β levels in BAL fluid. This inflammatory response was significantly suppressed by roflumilast and dexamethasone. The close similarity of marmoset and human lungs regarding LPS-induced inflammation and the significant anti-inflammatory effect of approved pharmaceuticals assess the suitability of marmoset monkeys to serve as a promising model for studying anti-inflammatory drugs
Propofol administration to the maternal-fetal unit improved fetal EEG and influenced cerebral apoptotic pathway in preterm lambs suffering from severe asphyxia
No full textBACKGROUND: Term and near-term infants are at high risk of developing brain injury and life-long disability if they have suffered from severe perinatal asphyxia. We hypothesized that propofol administration to the maternal-fetal unit can diminish cerebral injury in term and near-term infant fetuses in states of progressive severe asphyxia. METHODS: Forty-four late preterm lambs underwent total umbilical cord occlusion (UCO) or sham treatment in utero. UCO resulted in global asphyxia and cardiac arrest. After emergency cesarean section under either maternal propofol or isoflurane anesthesia, the fetuses were resuscitated and subsequently anesthetized the same way as their mothers. RESULTS: Asphyctic lambs receiving isoflurane showed a significant increase of total and low-frequency spectral power in bursts indicating seizure activity and more burst-suppression with a marked increase of interburst interval length during UCO. Asphyctic lambs receiving propofol showed less EEG changes. Propofol increased levels of anti-apoptotic B-cell lymphoma-extra large (Bcl-xL) and phosphorylated STAT-3 and reduced the release of cytochrome c from the mitochondria and the protein levels of activated cysteinyl aspartate-specific protease (caspase)-3, -9, and N-methyl-d-aspartate (NMDA) receptor. CONCLUSIONS: Improvement of fetal EEG during and after severe asphyxia could be achieved by propofol treatment of the ovine maternal-fetal unit. The underlying mechanism is probably the reduction of glutamate-induced cytotoxicity by down-regulation of NMDA receptors and an inhibition of the mitochondrial apoptotic pathway
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