Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Marcos Schwab is active.

Publication


Featured researches published by Marcos Schwab.


Circulation | 2010

Pulmonary and Systemic Vascular Dysfunction in Young Offspring of Mothers With Preeclampsia

Pierre-Yves Jayet; Stefano F. Rimoldi; Thomas Stuber; Carlos Salinas Salmòn; Damian Hutter; Emrush Rexhaj; Sébastien Thalmann; Marcos Schwab; Pierre Turini; Céline Sartori-Cucchia; Pascal Nicod; Mercedes Villena; Yves Allemann; Urs Scherrer; Claudio Sartori

Background— Adverse events in utero may predispose to cardiovascular disease in adulthood. The underlying mechanisms are unknown. During preeclampsia, vasculotoxic factors are released into the maternal circulation by the diseased placenta. We speculated that these factors pass the placental barrier and leave a defect in the circulation of the offspring that predisposes to a pathological response later in life. The hypoxia associated with high-altitude exposure is expected to facilitate the detection of this problem. Methods and Results— We assessed pulmonary artery pressure (by Doppler echocardiography) and flow-mediated dilation of the brachial artery in 48 offspring of women with preeclampsia and 90 offspring of women with normal pregnancies born and permanently living at the same high-altitude location (3600 m). Pulmonary artery pressure was roughly 30% higher (mean±SD, 32.1±5.6 versus 25.3±4.7 mm Hg; P<0.001) and flow-mediated dilation was 30% smaller (6.3±1.2% versus 8.3±1.4%; P<0.0001) in offspring of mothers with preeclampsia than in control subjects. A strong inverse relationship existed between flow-mediated dilation and pulmonary artery pressure (r=−0.61, P<0.001). The vascular dysfunction was related to preeclampsia itself because siblings of offspring of mothers with preeclampsia who were born after a normal pregnancy had normal vascular function. Augmented oxidative stress may represent an underlying mechanism because thiobarbituric acid–reactive substances plasma concentration was increased in offspring of mothers with preeclampsia. Conclusions— Preeclampsia leaves a persistent defect in the systemic and the pulmonary circulation of the offspring. This defect predisposes to exaggerated hypoxic pulmonary hypertension already during childhood and may contribute to premature cardiovascular disease in the systemic circulation later in life.


Chest | 2010

Exaggerated Pulmonary Hypertension During Mild Exercise in Chronic Mountain Sickness

Thomas Stuber; Claudio Sartori; Marcos Schwab; Pierre-Yves Jayet; Stefano F. Rimoldi; Sophie Garcin; Sébastien Thalmann; Hilde Spielvogel; Carlos Salinas Salmòn; Mercedes Villena; Urs Scherrer; Yves Allemann

BACKGROUND Chronic mountain sickness (CMS) is an important public health problem and is characterized by exaggerated hypoxemia, erythrocytosis, and pulmonary hypertension. While pulmonary hypertension is a leading cause of morbidity and mortality in patients with CMS, it is relatively mild and its underlying mechanisms are not known. We speculated that during mild exercise associated with daily activities, pulmonary hypertension in CMS is much more pronounced. METHODS We estimated pulmonary artery pressure by using echocardiography at rest and during mild bicycle exercise at 50 W in 30 male patients with CMS and 32 age-matched, healthy control subjects who were born and living at an altitude of 3,600 m. RESULTS The modest, albeit significant difference of the systolic right-ventricular-to-right-atrial pressure gradient between patients with CMS and controls at rest (30.3 +/- 8.0 vs 25.4 +/- 4.5 mm Hg, P 5 .002) became more than three times larger during mild bicycle exercise (56.4 +/- 19.0 vs 39.8 +/- 8.0 mm Hg, P < .001). CONCLUSIONS Measurements of pulmonary artery pressure at rest greatly underestimate pulmonary artery pressure during daily activity in patients with CMS. The marked pulmonary hypertension during mild exercise associated with daily activity may explain why this problem is a leading cause of morbidity and mortality in patients with CMS.


The Journal of Physiology | 2008

Stimulation of peroxynitrite catalysis improves insulin sensitivity in high fat diet-fed mice

Hervé Duplain; Claudio Sartori; Pierre Dessen; Pierre-Yves Jayet; Marcos Schwab; Jonathan Bloch; Pascal Nicod; Urs Scherrer

Peroxynitrite synthesis is increased in insulin resistant animals and humans. Peroxynitirite‐induced nitration of insulin signalling proteins impairs insulin action in vitro, but the role of peroxynitrite in the pathogenesis of insulin resistance in vivo is not known. We therefore assessed the effects of a 1‐week treatment with the peroxynitrite decomposition catalyst FeTPPS on insulin sensitivity in insulin resistant high fat diet‐fed (HFD) and control mice. FeTPPS normalized the fasting plasma glucose and insulin levels (P < 0.01), attenuated the hyperglycaemic response to an intraperitoneal glucose challenge by roughly 50% (P < 0.05), and more than doubled the insulin‐induced decrease in plasma glucose levels in HFD‐fed mice (P < 0.001). Moreover, FeTPPS restored insulin‐stimulated Akt phosphorylation and insulin‐stimulated glucose uptake in isolated skeletal muscle in vitro. Stimulation of peroxynitrite catalysis attenuates HFD‐induced insulin resistance in mice by restoring insulin signalling and insulin‐stimulated glucose uptake in skeletal muscle tissue.


Chest | 2008

Respiratory Nitric Oxide and Pulmonary Artery Pressure in Children of Aymara and European Ancestry at High Altitude

Thomas Stuber; Claudio Sartori; Carlos Salinas Salmòn; Damian Hutter; Sébastien Thalmann; Pierre Turini; Pierre-Yves Jayet; Marcos Schwab; Céline Sartori-Cucchia; Mercedes Villena; Urs Scherrer; Yves Allemann

Invasive studies suggest that healthy children living at high altitude display pulmonary hypertension, but the data to support this assumption are sparse. Nitric oxide (NO) synthesized by the respiratory epithelium regulates pulmonary artery pressure, and its synthesis was reported to be increased in Aymara high-altitude dwellers. We hypothesized that pulmonary artery pressure will be lower in Aymara children than in children of European ancestry at high altitude, and that this will be related to increased respiratory NO. We therefore compared pulmonary artery pressure and exhaled NO (a marker of respiratory epithelial NO synthesis) between large groups of healthy children of Aymara (n = 200; mean +/- SD age, 9.5 +/- 3.6 years) and European ancestry (n = 77) living at high altitude (3,600 to 4,000 m). We also studied a group of European children (n = 29) living at low altitude. The systolic right ventricular to right atrial pressure gradient in the Aymara children was normal, even though significantly higher than the gradient measured in European children at low altitude (22.5 +/- 6.1 mm Hg vs 17.7 +/- 3.1 mm Hg, p < 0.001). In children of European ancestry studied at high altitude, the pressure gradient was 33% higher than in the Aymara children (30.0 +/- 5.3 mm Hg vs 22.5 +/- 6.1 mm Hg, p < 0.0001). In contrast to what was expected, exhaled NO tended to be lower in Aymara children than in European children living at the same altitude (12.4 +/- 8.8 parts per billion [ppb] vs 16.1 +/- 11.1 ppb, p = 0.06) and was not related to pulmonary artery pressure in either group. Aymara children are protected from hypoxic pulmonary hypertension at high altitude. This protection does not appear to be related to increased respiratory NO synthesis.


High Altitude Medicine & Biology | 2008

Pulmonary-artery pressure and exhaled nitric oxide in Bolivian and Caucasian high altitude dwellers

Marcos Schwab; Pierre-Yves Jayet; Thomas Stuber; Carlos Salinas; Jonathan Bloch; Hilde Spielvogel; Mercedes Villena; Yves Allemann; Claudio Sartori; Urs Scherrer

There is evidence that high altitude populations may be better protected from hypoxic pulmonary hypertension than low altitude natives, but the underlying mechanism is incompletely understood. In Tibetans, increased pulmonary respiratory NO synthesis attenuates hypoxic pulmonary hypertension. It has been speculated that this mechanism may represent a generalized high altitude adaptation pattern, but direct evidence for this speculation is lacking. We therefore measured systolic pulmonary-artery pressure (Doppler chocardiography) and exhaled nitric oxide (NO) in 34 healthy, middle-aged Bolivian high altitude natives and in 34 age- and sex-matched, well-acclimatized Caucasian low altitude natives living at high altitude (3600 m). The mean+/-SD systolic right ventricular to right atrial pressure gradient (24.3+/-5.9 vs. 24.7+/-4.9 mmHg) and exhaled NO (19.2+/-7.2 vs. 22.5+/-9.5 ppb) were similar in Bolivians and Caucasians. There was no relationship between pulmonary-artery pressure and respiratory NO in the two groups. These findings provide no evidence that Bolivian high altitude natives are better protected from hypoxic pulmonary hypertension than Caucasian low altitude natives and suggest that attenuation of pulmonary hypertension by increased respiratory NO synthesis may not represent a universal adaptation pattern in highaltitude populations.


Circulation | 2011

Response to Letters Regarding Article, “Pulmonary and Systemic Vascular Dysfunction in Young Offspring of Mothers With Preeclampsia”

Stefano F. Rimoldi; Pierre-Yves Jayet; Emrush Rexhaj; Sébastien Thalmann; Marcos Schwab; Pierre Turini; Céline Sartori-Cucchia; Pascal Nicod; Urs Scherrer; Claudio Sartori; Damian Hutter; Thomas Stuber; Yves Allemann; Carlos Salinas Salmòn; Mercedes Villena

We thank Lazdam et al and Yuan et al for their interesting comments on our study.1 Lazdam et al point out that in our study, birth weight in offspring of mothers with preeclampsia was significantly lower than in controls, and suggest that the vascular impairment in offspring was caused by a combination of the independent effects of preeclampsia and intrauterine growth restriction rather than by preeclampsia per se. To test this hypothesis, we performed a subgroup analysis of 15 offspring of mothers with preeclampsia and 15 controls matched for birth weight (3080±291 versus 3077±398 g; P =0.98). We found that the difference in flow-mediated dilation between birth-weight-matched offspring of preeclampsia and controls (6.4%±1.3% versus 8.9%±1.2%; P <0.0001) tended to be even larger …


Medicina-buenos Aires | 2005

Prevalencia de hipertensión arterial en una comunidad aborigen del norte argentino

Eduardo Coghlan; Luciana Bella Quero; Marcos Schwab; Débora Pellegrini; Hernán Trimarchi


European Journal of Internal Medicine | 2015

Patients' characteristics associated with the decision of "do not attempt cardiopulmonary resuscitation" order in a Swiss hospital

Fabienne Chevaux; Mariangela Gagliano; Gérard Waeber; Pedro Marques-Vidal; Marcos Schwab


Clinical & Biomedical Research | 2009

Consultoria em Ética Clínica na Suíça

Marcos Schwab; Rouven Porz


Medicina-buenos Aires | 2008

Defecto en la homeostasis del óxido nítrico: Mecanismo común subyacente de la insulino-resistencia, la hiperactividad simpática y la morbi-mortalidad cardiovascular

Marcos Schwab; Jonathan Bloch; Hervé Duplain; Claudio Sartori; Urs Scherrer

Collaboration


Dive into the Marcos Schwab's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Urs Scherrer

University of Tarapacá

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Thomas Stuber

Imperial College Healthcare

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge