Texture evolution during deep-drawing processes

peer reviewedThis paper presents a constitutive law based on Taylor’s model implemented in our non-linear finite element code LAGAMINE. The yield locus is only locally described and a particular interpolation method has been developed. This local yield locus model uses a discrete representation of the material’s texture. The interpolation method is presented and a deep-drawing application is simulated in order to show up the influence of the texture evolution during forming processes

Lung transplantation for interstitial lung disease in idiopathic inflammatory myositis: A cohort study

Connective tissue disease; Idiopathic inflammatory myopathy; Interstitial lung diseaseEnfermedad del tejido conectivo; Miopatía inflamatoria idiopática; Enfermedad pulmonar intersticialMalaltia del teixit conjuntiu; Miopatia inflamatòria idiopàtica; Malaltia pulmonar intersticialIn patients with interstitial lung disease (ILD) complicating classical or amyopathic idio-pathic inflammatory myopathy (IIM), lung transplantation outcomes might be affected by the disease and treatments. Here, our objective was to assess survival and prog-nostic factors in lung transplant recipients with IIM-ILD. We retrospectively reviewed data for 64 patients who underwent lung transplantation between 2009 and 2021 at 19 European centers. Patient survival was the primary outcome. At transplantation, the median age was 53 [46–59] years, 35 (55%) patients were male, 31 (48%) had clas-sical IIM, 25 (39%) had rapidly progressive ILD, and 21 (33%) were in a high- priority transplant allocation program. Survival rates after 1, 3, and 5 years were 78%, 73%, and 70%, respectively. During follow-up (median, 33 [7–63] months), 23% of patients developed chronic lung allograft dysfunction. Compared to amyopathic IIM, classical IIM was characterized by longer disease duration, higher-intensity immunosuppres-sion before transplantation, and significantly worse posttransplantation survival. Five (8%) patients had a clinical IIM relapse, with mild manifestations. No patient expe-rienced ILD recurrence in the allograft. Posttransplantation survival in IIM-ILD was similar to that in international all- cause- transplantation registries. The main factor as-sociated with worse survival was a history of muscle involvement (classical IIM). In lung transplant recipients with idiopathic inflammatory myopathy, survival was similar to that in all-cause transplantation and was worse in patients with muscle involvement compared to those with the amyopathic disease

Allogeneic Hematopoietic Stem Cell Transplantation After Prior Lung Transplantation for Hereditary Pulmonary Alveolar Proteinosis: A Case Report

Pulmonary alveolar proteinosis (PAP) is a rare, diffuse lung disorder characterized by surfactant accumulation in the small airways due to defective clearance by alveolar macrophages, resulting in impaired gas exchange. Whole lung lavage is the current standard of care treatment for PAP. Lung transplantation is an accepted treatment option when whole lung lavage or other experimental treatment options are ineffective, or in case of extensive pulmonary fibrosis secondary to PAP. A disadvantage of lung transplantation is recurrence of PAP in the transplanted lungs, especially in hereditary PAP. The hereditary form of PAP is an ultra-rare condition caused by genetic mutations in genes encoding for the granulocyte macrophage-colony stimulating factor (GM-CSF) receptor, and intrinsically affects bone marrow derived-monocytes, which differentiate into macrophages in the lung. Consequently, these macrophages typically display disrupted GM-CSF receptor-signaling, causing defective surfactant clearance. Bone marrow/hematopoietic stem cell transplantation may potentially reverse the lung disease in hereditary PAP. In patients with hereditary PAP undergoing lung transplantation, post-lung transplant recurrence of PAP may theoretically be averted by subsequent hematopoietic stem cell transplantation, which results in a graft-versus-disease (PAP) effect, and thus could improve long-term outcome. We describe the successful long-term post-transplant outcome of a unique case of end-stage respiratory failure due to hereditary PAP-induced pulmonary fibrosis, successfully treated by bilateral lung transplantation and subsequent allogeneic hematopoietic stem cell transplantation. Our report supports treatment with serial lung and hematopoietic stem cell transplantation to improve quality of life and prolong survival, without PAP recurrence, in selected patients with end-stage hereditary PAP

Resting and exercise functionnal aspects in pulmonary arterial hypertension

Cette thèse, intitulée « L’exploration fonctionnelle de repos et à l’exercice dans l'hypertension pulmonaire », est le résultat de différents travaux de physiologie clinique effectués dans le cadre des maladies vasculaires pulmonaires (MVP).La première partie de cette thèse est consacrée à l’étude de la diffusion des gaz dans l’hypertension artérielle pulmonaire (HTAP), l’hypertension pulmonaire thromboembolique chronique (HTP-TEC) et la maladie veino-occlusive pulmonaire (MVOP). Nous nous sommes particulièrement intéressé à l’étude de la double diffusion du monoxyde de carbone (DLCO) et d’azote (DLNO), permettant notamment la mesure du volume capillaire (Vc) et de la diffusion membranaire (Dm). Nous avons mis en évidence une diminution significative de ces paramètres dans les trois maladies et plus particulièrement dans la MVOP. Cette pathologie a la particularité de présenter un rapport DLNO/DLCO significativement plus élevé, évocateur de l’hémangiomatose capillaire associée à l’atteinte veinulaire. De plus, nous avons mis en évidence que le volume capillaire et la diffusion membranaire sont corrélés aux paramètres de capacités à l’exercice, dont la consommation en oxygène (VO2), dans un groupe de patients avec HTAP indemnes de toute comorbidité. Enfin, nous avons mis en évidence une corrélation significative entre la Dm et la survie dans l’HTAP.La deuxième partie de cette thèse fait référence a l’étude du cathétérisme cardiaque droit durant l’exercice. Dans un premier travail, nous avons collaboré à la proposition d’une nouvelle définition de l’hypertension pulmonaire à l’exercice (HTPe). Dans une cohorte rétrospective de patients investigués au Centre National de référence de l’Hypertension Pulmonaire, nous avons montré que l’association de résistances pulmonaires totales supérieures à 3 UW au pic de l’effort avec une pression artérielle pulmonaire moyenne (PAPm) supérieure à 30 mmHg présentent des valeurs de sensibilités et de spécificités élevées pour le diagnostic de patients avec MVP ou cardiopathie gauche sans hypertension pulmonaire de repos. Nous avons confronté ces résultats à une cohorte historique de sujets sains et trouvé des valeurs similaires. Dans un autre travail, nous avons analysé la concordance entre trois différentes définitions utilisées jusqu’à présent dans la littérature concernant l’HTPe, en montrant qu’elles ne sont pas équivalentes. Enfin, nous avons collaboré à une étude hémodynamique des sujets présentant une PAPm au repos comprise en 21 et 24 mmHg. Nous avons démontré que ces sujets présentent une hémodynamique d’effort anormale et qu’il existe une association entre la PAPm de repos et la fréquence de l’ HTPe.Dans la troisième partie de la thèse, nous avons contribué à l’étude de la distensibilité vasculaire dans les MVP. Dans une première étude rétrospective, nous avons collaboré à la validation du modèle alpha de distensibilité vasculaire. Nous avons démontré dans une cohorte de sujets avec maladies vasculaires pulmonaires que le coefficient alpha permet de détecter précocement des anomalies de la circulation pulmonaire chez des sujets présentant une PAPm de repos inférieure à 25 mmHg. De plus, dans une étude prospective, nous avons également étudié une nouvelle technique diagnostic : le signal Doppler pulmonaire, basé sur la pulsatilité de la paroi vasculaire, et donc reflétant la distensibilité des vaisseaux. Nous avons démontré que la performance diagnostique de cette technique était tout à fait acceptable en comparaison avec le cathétérisme cardiaque droit.Enfin, dans la dernière partie, nous avons exploré les différences de réponses à l’effort entre un groupe de patients avec HTAP et un groupe de patients avec une forme distale d’HTP-TEC. Nous avons observé une réponse ventilatoire différente, notamment avec une inefficience ventilatoire plus importante liée à un effet espace mort, expliquant une partie de la limitation fonctionnelle.This thesis, entitled « Rest and exercice functional investigation in pulmonary hypertension » is the sum of several physiological and clinical works in the field of pulmonary vascular diseases (PVD).The first part of this thesis is focused on the study of gas diffusion in pulmonary arterial hypertension (PAH), chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary veno-occlusive disease (PVOD). We have a special interest in the study of combined nitric oxide diffusion (DLNO) and carbon monoxide diffusion (DLCO) technic, which allows the measurement of capillary blood volume (Vc) and membrane diffusion (Dm). We have demonstrated a significant decrease of those parameters in the three forms of PH, specifically emphasized in PVOD. Furthermore, DLNO/DLCO ratio was remarkably increased in PVOD, suggesting a component of capillary hemangiomatosis associated to venular remodeling. Moreover, we have demonstrated that Vc and Dm were correlated to exercice capacity, such as peak VO2, in a group of PAH patients without confunding factors. Finally, we have found a significant correlation between Dm and survival in PAH.The second part of this thesis was about right heart catheterization during exercice. In this work, we have collaborated to the proposition of a new definition of exercice pulmonary hypertension (ePH). In a retrospective cohort of patients investigated in the French National Center for Pulmonary Hypertension, we have shown that total pulmonary resistance above 3 WU during exercise associated with a mean pulmonary arterial pressure (mPAP) above 30 mmHg displayed high sensitiviy and specificity for diagnosis of patients with PVD or left heart disease without resting pulmonary hypertension. We have compared these results with an historical cohort of healthy subjects and found similar results. In an other work, we have analyzed the concordance between three different definitions of ePH recently used in the litterature. We have demonstrated that they were not equivalent. Finally, we have collaborated to an haemodynamic study of subjects with resting mPAP between 21 and 24 mmHg. We have demonstrated that these subjects displayed abnormal haemodynamics during exercice. We have also demonstated that a progressive rise of resting mPAP was associated with an increase of the frequence of ePH.The third part of this manuscript is consacrated to the study of pulmonary vascular ditensibility in PVD. In a retrospective study, we have collaborated to the validation of the alpha model which allow the estimation of a distensibility coefficient. We have demonstrated in a cohort of patients with PVD that alpha allowed the early detection of abnormal pulmonary circulation in subjects with normal mPAP. In a prospective study, we have used a new technic called the lung Doppler signal (LDS) to diagnose PH, which investigates the pulsatile distensibility of pulmonary vascular walls. We have demonstated that LDS diagnostic performance was acceptable in comparison with the gold standard right heart catheterization.Finally, in the last part of the thesis, we have investigated differences of exercice profile between patients with PAH and distal CTEPH. We have demonstated an abnormal ventilatory pattern, with hyperventilation and marked ventilatory inefficiency in distal CTEPH. This is related to the increased physiological deadspace, which explained a part of fonctional limitation in distal CTEPH

Comparison of airway remodeling in asthma and COPD]

peer reviewedAsthma and COPD (chronic obstructive pulmonary disease) are two pulmonary obstructive diseases. It is well recognized that inflammation plays a key role in the pathogenesis of these two diseases. However, inflammation per se does not entirely account for the progressive loss in pulmonary function. It is admitted that the functional changes partly relate to airway structural alteration called remodeling. In this review we summarize the most frequent tissue abnormalities found in patients with asthma and COPD and report on the relationship between structural alterations and clinical features of the disease

Micro-macro analysis of steel sheet behaviour in finite element simulations. Application to deep-drawing process.

peer reviewedThis paper presents a constitutive law based on Taylor’s model implemented in our non-linear finite element code LAGAMINE. The yield locus is only locally described and a particular interpolation method has been developed. This local yield locus model uses a discrete representation of the material’s texture. The interpolation method is presented and a deep-drawing application is simulated in order to show up the influence of the texture evolution during forming processes

Spasmolytics indication in renal colic: a literature review

peer reviewedLes différents spasmolytiques sont souvent prescrits par les médecins généralistes ou dans les services d’urgence dès que le diagnostic de colique néphrétique est posé. Une pratique cependant contestée. Cet article a pour but de faire une revue de la littérature de l’efficacité des spasmolytiques dans la colique néphrétique, et d’opposer celle-ci à la pratique quotidienne, ainsi que de faire le point sur les effets secondaires. Conclusion : la revue de l’EBM sur le sujet ne permet pas de prouver l’efficacité des spasmolytiques, et montre qu’il est préférable d’utiliser le diclofenac en monothérapie et de traiter les patients non contrôlés par tramadol et antalgiques. Il faudra adjoindre du tamsulosine pour les calculs du bas uretère

Validation of a FEM model coupled with texture applied to deep drawing process

peer reviewedThis paper presents a constitutive law based on the Taylor model implemented in our non linear finite element code LAGAMINE. The yield locus is only locally described and the interpolation method is presented. This local yield locus model uses a discrete representation of the material's texture. The influence of this discrete representation and a deep-drawing simulation are presented

Implementation of a texture based interpolated yield locus in a FEM code

peer reviewedThis paper presents a constitutive law based on Taylor's model implemented in our non linear finite element code LAGAMINE. The yield locus is only described and a particular interpolation method has been developed. This local yield locus model uses a discrete representation of the material's texture. The interpolation method is presented and a deep-drawing application is simulated in order to show up the influence of the texture evolution during forming processes

Texture effects on steel sheet behaviour under large strain simulations

peer reviewe