PubMed Health⌕ Search

Biomedical subjects

H Bounameaux

Publications and source records attributed to H Bounameaux.

At least 19 recordsLinked to original sources
PubMed2007

Characterization of endothelial-like cells derived from human mesenchymal stem cells.

BACKGROUND: Blood-derived endothelial progenitor cells (EPC) have been used to treat ischemic disease. However, the number of EPC that can be obtained from adult blood is limited. OBJECTIVE: To characterize endothelial-like cells obtained from human bone marrow and determine their ability to stimulate new blood vessel formation in vivo. METHODS: Mononuclear cells (MNC) were isolated from human bone marrow or umbilical cord blood and cultured in endothelial growth medium (EGM-2). Mesenchymal stem cells (MSC) were isolated from bone marrow and induced to differentiate into endothelial-like cells (MSCE), or adipocytes or osteocytes by growth in EGM-2, adipogenic or osteogenic medium. RESULTS: Cells obtained by culturing bone marrow MNC in EGM-2 formed cord- or tube-like structures when grown on Matrigel(TM) and expressed several endothelial marker proteins. However, cell morphology and the profile of endothelial marker protein expression were different from those of cord blood-derived EPC (cbEPC). Cells with a similar phenotype were obtained by differentiation of MSC into MSCE, which was accompanied by an increase of endothelial marker proteins and a diminished capacity to differentiate into adipocytes. Subcutaneous implantation of MSCE in collagen plugs in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice resulted in formation of functional blood vessels that had incorporated the MSCE. CONCLUSIONS: Our results show that MSCE and cbEPC are different cell types. The formation of functional blood vessels by MSCE, combined with high yields and a reduced capacity to differentiate into other cell types compared with MSC, makes these cells potentially useful for autologous therapy of ischemic disease.

Adipocytes↗
PubMed2006

Ten years after...

Explore the source record for details and available documents.

Administration, Oral↗
PubMed2006

D-dimer, factor VIII coagulant activity, low-intensity warfarin and the risk of recurrent venous thromboembolism.

BACKGROUND: Elevated plasma D-dimer and factor VIII coagulant activity (FVIIIc) may be associated with the risk of recurrent venous thromboembolism (VTE). OBJECTIVES: To evaluate D-dimer and FVIIIc as risk factors for recurrent VTE and assess the efficacy of extended low-intensity warfarin (target International Normalized Ratio 1.5-2.0) in preventing recurrence by biomarker level. PATIENTS AND METHODS: In the Prevention of Recurrent Venous Thromboembolism trial, 508 idiopathic VTE patients treated for > or = 3 months with full-intensity warfarin, and who had stopped warfarin for 7 weeks on average, were randomized to low-intensity warfarin or placebo and followed for 2.1 years for recurrent VTE. Prerandomization blood samples were analysed for D-dimer and FVIIIc. RESULTS: One-third of participants had elevated baseline D-dimer (> or = 500 ng mL(-1)) and one-fourth, elevated FVIIIc (> or = 150 IU dL(-1)). Adjusting for other risk factors, the hazard ratios (HRs) for recurrent VTE with elevated D-dimer or FVIIIc were 2.0 [95% confidence interval (CI) 1.2-3.4] and 1.5 (95% CI 0.8-2.8), respectively. The association of elevated D-dimer with recurrence was larger among patients with one prior VTE (HR 3.2, 95% CI 1.3-8.0) than in patients with more than one event (HR 1.4, 95% CI 0.7-2.2). For patients with one prior VTE on placebo, the annual recurrence incidence was 10.9% with elevated D-dimer and 2.9% with normal values. Low-intensity warfarin was equally effective in recurrence risk reduction in those with normal or elevated biomarkers. CONCLUSIONS: Among patients with idiopathic VTE, measurement of D-dimer, but not FVIIIc, might be useful for risk stratification. The efficacy of extended low-intensity warfarin therapy did not vary by biomarker level.

Adult↗
PubMed2005

[Diagnosis of suspected deep venous thrombosis and pulmonary embolism during pregnancy].

Venous thromboembolic disease (VTE) is a frequent clinical problem during pregnancy and post-partum. Pulmonary embolism (PE) remains the most common cause of mortality during pregnancy and post-partum in western countries. In the majority of cases, DVT may be diagnosed by non-invasive tests such as clinical probability, D-dimer measurement and venous compression ultrasonography. In contrast, at least one irradiating invasive exam is necessary in suspected PE. The lung scan, the most validated diagnostic test for PE during pregnancy and fetal irradiation is quite low, in particular if only perfusion lung scan is used. Helical computed tomography (hCT) has widely replaced lung scan in the diagnostic approach of suspected pulmonary embolism. However, it has never been validated in pregnant women.

Adult↗
PubMed2005

Venous thromboembolism prophylaxis in acutely ill medical patients: definite need for improvement.

AIM OF THE STUDY: To examine the frequency and adequacy of thromboprophylaxis in acutely ill medical patients hospitalized in eight Swiss medical hospitals. METHODS: A cross-sectional study of 1372 patients from eight Swiss hospitals was carried out. After exclusion of patients (275) given therapeutic anticoagulation, 1097 patients were audited. The adequacy of thromboprophylaxis was assessed by comparison with predefined explicit criteria. RESULTS: Of 1097 patients, 542 (49.4%) received thromboprophylaxis. According to the explicit criteria, 644 (58.7%) should have been on prophylaxis (P < 0.001, when compared with the rate observed). The rate of prevention differed widely between hospitals (from 29.4 to 88.6%) with no difference between teaching and nonteaching hospitals. According to the explicit criteria, a substantial proportion (44.9%) of the patients who should have been treated were not. Conversely, 41.3% of the patients were unnecessarily treated. CONCLUSIONS: Even though the appropriateness of the explicit criteria used could be challenged, our data suggest that the current practice is associated with important uncertainty leading to both overuse and underuse of thromboprophylaxis in patients hospitalized in medical wards. More efforts are urgently needed to develop new or endorse existing explicit, evidence-based criteria and guidelines for thromboprophylaxis in this population of patients.

Acute Disease↗
PubMed2005

Swiss Atherothrombosis Survey: a field report on the occurrence of symptomatic and asymptomatic peripheral arterial disease.

OBJECTIVES: To investigate the Ankle/Brachial Pressure Index (ABI) for its suitability in daily practice to identify patients at atherothrombotic risk. To collect data on the prevalence of atherothrombotic events [coronary artery disease (CAD), stroke/transient ischaemic attack (TIA)], of 'hidden' (asymptomatic) versus 'known' (symptomatic) peripheral arterial disease (PAD) and treatment in the general practice population. DESIGN: Field survey from everyday Swiss practice. On five consecutive workdays, 276 doctors documented all patients, recording gender, age, history of atherothrombotic events, risk factors and family history. In the case of a previous stroke/TIA and/or CAD, or two or more risk factors were present at age >55, the ABI was determined. A total of 25,351 patients were included and 3921 ABI measurements were performed in eligible patients. SETTING: Practices of primary care doctors. PARTICIPANTS: All patients who visited one of the 276 participating doctors on one of five consecutive workdays were included in the survey. INTERVENTION: Data recording and measurement of the ABI on those patients who qualified. RESULTS: Of the patients 3.7% had symptomatic PAD. An additional 2.7% of hitherto asymptomatic patients were identified as being at high atherothrombotic risk by having an ABI value <0.9. Exactly 93.9% of the participating doctors considered the ABI measurement easy to incorporate into the diagnostic routine of patients presenting with risk factors. CONCLUSIONS: The ABI measurement is an easy-to-use, noninvasive and reliable means to identify patients at risk of atherothrombotic events. Identification of asymptomatic PAD leads to intensified targeted prophylactic atherothrombotic treatment that can reduce morbidity and mortality.

Aged↗
PubMed2005

Differential value of risk factors and clinical signs for diagnosing pulmonary embolism according to age.

INTRODUCTION: The diagnostic value of clinical presentation of pulmonary embolism (PE) is uncertain in the elderly, who often have concomitant cardiopulmonary diseases that may mimic PE. The aim of our study was to assess the differential value of risk factors, symptoms and clinical signs of venous thromboembolism, results of electrocardiogram and chest X-ray for the diagnosis of PE in suspected patients according to age. METHODS: We analyzed data from two outcome studies which enrolled 1721 consecutive patients presenting in the emergency department with clinically suspected PE defined as acute onset of new or worsening shortness of breath or chest pain without any other obvious etiology. All patients underwent a sequential diagnostic work-up and a 3-month follow-up. RESULTS: The proportion of confirmed PE was 24.2% (416 of 1721). Strength of the association with PE did not differ according to age group for history of venous thromboembolism (VTE), recent surgery, tachypnea at admission or right ventricular strain on electrocardiogram. Active malignancy, hemoptysis, tachycardia, hemidiaphragmatic elevation and pleural effusion at chest X-ray were no more associated with PE in the patients aged of 75 years or more. Finally, symptoms and signs of deep venous thrombosis, and an alternative diagnosis less probable than PE were associated with PE in all age groups, but the strength of this association decreased significantly with advancing age. CONCLUSION: Some risk factors, symptoms and signs of VTE are less strongly or even not at all associated with PE in the elderly. Physicians should take this into account when attending elderly patients suspected of PE and when assessing their clinical probability of PE.

Age Factors↗
PubMed2004

[The COPD-PE study: prevalence and prediction of pulmonary embolism in acute exacerbations of chronic obstructive pulmonary disease].

INTRODUCTION: Patients suffering from chronic obstructive pulmonary disease (COPD) are often admitted to hospital with an exacerbation of their disease that manifests itself with an increase in cough and/or sputum, increased dyspnoea and sometimes chest pain. These episodes are most often attributed to an acute exacerbation of bronchial infection but the real cause is often unknown. COPD is considered a risk factor for pulmonary embolism (PE) and PE is part of the differential diagnosis of an acute exacerbation of COPD. However, the symptoms of these two conditions overlap to a considerable extent and the investigation of PE is often ignored in these patients. Therefore the true prevalence of PE in this situation is unknown. Nevertheless several small series suggest that up to 30% of patients seen as emergencies with exacerbations of COPD may have a deep vein thrombosis or PE. The aims of this study are therefore: 1. To evaluate the prevalence of PE in patients admitted as emergencies with exacerbations of COPD; and 2. To attempt to develop a prediction guide for PE in this population in order to identify the patients in whom PE should be investigated. MATERIALS AND METHODS: 600 consecutive patients admitted as emergencies with exacerbations of COPD will be included in a cross sectional study in three university hospitals (Geneva and Lausanne in Switzerland, and Amiens in France). Patients fulfilling the inclusion criteria will be investigated by a diagnostic algorithm appropriate for the study of PE, including D-dimer levels and, in those with abnormal results, ultrasonic scan of the deep veins of the legs and spiral CT scan. The patient characteristics on admission will be incorporated in a multivariate regression analysis in an attempt to identify the predictive factors for PE in these patients. The expected duration of the study is 24 months. EXPECTED RESULTS: This study should determine the prevalence of PE in patients admitted as emergencies with exacerbations of COPD and therefore help decide when, and in which patients, a systematic search for PE should be undertaken.

Algorithms↗
PubMed2004

Relationship between sympathetic reactivity and body weight loss in morbidly obese subjects.

OBJECTIVE: To investigate the possible role of peripheral sympathetic activity in gastric bypass-induced body weight loss. SUBJECTS AND METHODS: In 42 morbidly obese patients (sex: 36 f/6 m; BMI: 46.0+/-0.7 kg/m(2)) undergoing a gastric bypass, the skin vasoconstrictor reflex in answer to a deep inspiration was measured by laser Doppler fluximetry. The extent of vasoconstriction, measured at the second finger of the left hand, was expressed as percent reduction of the basal blood flux (% vasoconstriction). Insulin sensitivity was assessed before surgery in a subset of patients (n=11), by the method of euglycemic, hyperinsulinemic clamp. Body weight and composition were evaluated before, and 3, 6 and 12 months after surgery. At the same time points, energy intake (kJ/day) was evaluated by means of both food record diary and alimentary anamnesis. RESULTS: The % vasoconstriction, which was significantly (P=0.01) greater in normoglycemic subjects than in diabetic ones, was also significantly (P=0.03) related to the extent of insulin sensitivity measured during the euglycemic clamp. The % vasoconstriction showed a significant (P>0.0001), positive correlation with weight reduction obtained between the 6th and 12th months following surgery; as a consequence, % vasoconstriction was significantly (P=0.0004) related to the overall body weight loss achieved during the year following the operation. These correlations remained significant in multiple regression analysis with adjustment for age, initial body weight, plasma glucose and insulin (P=0.0007 and 0.006, respectively). The % vasoconstriction was also significantly (P=0.0006), negatively related to energy intake measured 12 months after surgery. CONCLUSIONS: In conditions of stable body weight, the sympathetic nervous system (SNS) reactivity is influenced by the degree of insulin resistance. A high capacity to activate the SNS, measured before surgery, is associated with both a larger gastric bypass-induced weight loss and a lower energy intake, at the phase of weight stabilization.

Adult↗
PubMed2004

Suspicion of pulmonary embolism in outpatients: nonspecific chest pain is the most frequent alternative diagnosis.

OBJECTIVES: Several recent studies have focused on identifying clinical predictors of embolism. However, although pulmonary embolism is ruled out in 70-85% of the patients in whom it is suspected, data on the clinical characteristics and discharge diagnosis of such patients are scarce. Our aim was to evaluate whether clinical characteristics would allow predicting alternative diagnoses other than pulmonary embolism thereby ruling out venous thromboembolism. DESIGN: Retrospective analysis. SETTING: Emergency centres of two teaching and general hospitals. SUBJECTS: A total of 1090 consecutive outpatients admitted for clinically suspected pulmonary embolism and a diagnosis established by a validated algorithm and a 3-month follow-up. OUTCOMES: Discharge diagnoses of patients in whom pulmonary embolism was ruled out were identified and regrouped into two categories: (i) nonspecific chest pain and (ii) diagnosis other than pulmonary embolism. Predictive accuracy of clinical and laboratory variables for diagnosing nonspecific chest pain was assessed by univariate and multivariate analysis. RESULTS: In patients without pulmonary embolism, nonspecific chest pain (parietal chest pain, chest pain of unknown origin and pleuritis) was the most frequent discharge diagnosis (n = 334, 31% of the entire cohort, 43% of the patients without pulmonary embolism). Other patients without pulmonary embolism had a wide variety of diagnoses, of which the most frequent were bronchopneumonia (6.0% of the entire cohort) and heart failure (5.2%). In the multivariate analysis, seven variables were strongly associated with nonspecific chest pain: younger age (below 40 years), female gender, respiratory rate below 20 min(-1), heart rate below 100 min(-1), and absence of recent immobilization, dyspnoea and haemoptysis. Two of the 24 patients in whom all those characteristics were present had pulmonary embolism (8%, 95% CI 3-22%). CONCLUSIONS: The most frequent discharge diagnosis in emergency ward patients in whom pulmonary embolism is ruled out is nonspecific chest pain. A clinical model did not allow to predict nonspecific chest pain with enough accuracy to rule out pulmonary embolism without further testing. Whether a more precise characterization of chest pain might allow an accurate identification of such patients deserves further study.

Adolescent↗