The evolution of several physical and biological systems, ranging from neutron transport in multiplying media to epidemics or population dynamics, can be described in terms of branching exponential flights, a stochastic process which couples a Galton-Watson birth-death mechanism with random spatial displacements. Within this context, one is often called to assess the length ℓ V that the process travels in a given region V of the phase space, or the number of visits n V to this same region. In this paper, we address this issue by resorting to the Feynman-Kac formalism, which allows characterizing the full distribution of ℓ V and n V and in particular deriving explicit moment formulas. Some other significant physical observables associated to ℓ V and n V , such as the survival probability, are discussed as well, and results are illustrated by revisiting the classical example of the rod model in nuclear reactor physics.

Background and Aim: Data on the clinical pharmacokinetics of cannabidiol (CBD) are scanty. We explored the effect of demographic and clinical variables on plasma concentrations of purified CBD in patients with Dravet (DS) and Lennox–Gastaut syndrome (LGS).Methods: The study design was an open, prospective, multicenter expanded access program (EAP). Venous blood samples were drawn from patients between 8 and 9 am, before the CBD morning dose, 12 h apart from the last evening dose, and then 2.5 h after their usual morning dose.Results: We collected 127 plasma samples (67-morning pre-dosing and 60 post-dosing) from 43 patients (24 females, 19 males), 27 with LGS and 16 with DS. Mean ± standard deviation age was 26 ± 15 years. Duration of CBD treatment averaged 4.2 ± 2.9 months at 13.2 ± 4.6 mg/kg/day. CBD median trough plasma concentration was 91 ng/ml; it doubled to 190 ng/ml 2.5 h post-dosing (p < 0.001). Cannabidiol trough plasma concentrations were linearly related to daily doses (r = 0.564, p < 0.001). Median trough CBD plasma concentration-to-weight-adjusted dose ratio (C/D) was 32% higher (p < 0.02) in plasma samples from subjects aged 18 and over than in those under 18. Sex and concomitant antiseizure medications (ASMs) were not associated with significant variations in CBD C/D, but caution is required due to the potential influence of confounders.Conclusion: These are the first data on CBD pharmacokinetics in children and adults with LGS or DS in a real-world setting. The most relevant finding was the higher CBD C/D in adults. In practice, reduced weight-normalized doses might be required with aging to achieve the same CBD plasma levels.

Objectives Acute aortic dissection type‐A (AADA) is a life threatening condition which requires emergency surgery. Surgery is usually performed by cardiac surgeons with various levels of aortic surgical experience. We compared the short‐term perioperative outcome and long‐term survival of patients operated by specialist aortic surgeons (SASs)and those who were operated by surgeons without specialist expertise. Methods A single center retrospective review of 232 patients who underwent acute surgery for AADA was conducted between 2005 and 2020. The cohort was divided into those operated on by SASs (Group A, n = 186) and those operated on by nonaortic surgeons (Group B, n = 46). Statistical comparison was done using regression modelling and groups were propensity matched. Kaplan–Meier comparison was undertaken using STATA14. Results Of 232 patients, 186 were operated on by an aortic specialist and 46 were operated by a nonaortic specialist. Overall 30‐day mortality was 10% in Group A compared to 26.0% in Group B (unadjusted: p = .01, multivariate: p = .02, and propensity matched p = .05). Long‐term mortality at 14 years was 26% in Group A compared to 52.0% in Group B (unadjusted: p = .001, multivariate: p = .001, and propensity matched: p = .01). Aortic surgeons performed a significantly higher number of aortic root procedures (43.0% vs. 17.3%, p = .001). The cross‐clamp time and bypass time was significantly shorter in Group A patients (89 vs. 105 min, p < .01 and 153 vs. 185, p = < .001). Postoperative requirement for renal filtration was (19% vs. 37%, unadjusted p = .01, multivariate p = .03 and propensity matched p = .04). Although postoperative bleeding was less in Group A (4.0% vs. 11.0%, unadjusted p = .05) after propensity matching it was not statistically significant. Conclusions In patients with AADA, surgery performed by aortic specialist's results in improved outcomes. Aortic specialists replaced more of dissected aorta, resulting in an increased number of complex procedures, which may explain improved long‐term survival after AADA in this cohort. This study adds further support in establishing a specialist aortic surgical service in cardiac centers.

No abstract

Le cancer colorectal est classé parmi les cancers les plus fréquents au monde (3ème rang après le cancer du sein et celui de la prostate), deuxième cancer digestif au Maroc après celui de l'estomac. Cependant son incidence dans notre pays reste moins élevée que celle des pays occidentaux (2.5 à 3.3/100 000 ha) mais rejoint celle des pays du Maghreb dont ce cancer touche les sujets jeunes dans 27% des cas. Le cancer colorectal (CCR) est un des meilleurs exemples du processus multi étape de cancérogenèse. La connaissance des caractéristiques anatomopathologique du CCR conditionnera certainement nos attitudes thérapeutiques. Nous avons mené une étude rétrospective épidémiologique et anatomopathologique au service de chirurgie viscérale de l'hôpital militaire Moulay Ismail à Meknès sur une période de 5 ans allant du mois de janvier 2012 au mois de Décembre 2016 (36 cas: 14 femmes et 22 hommes). À la lumière de cette étude, l'objectif de ce travail est d'analyser le profil épidémiologique et les aspects anatomopathologiques des cancers colorectaux. L'analyse de nos résultats montre un profil épidémiologique particulier qui se caractérise par un âge plus jeune, une répartition selon le sexe en faveur des hommes, les carcinomes sporadiques sont largement prédominants avec une répartition topographique recto sigmoïdienne fréquemment observée. Sur le plan pronostique, le faible degré de différenciation des adénocarcinomes et le type mucineux sont corrélés à un stade TNM et d'Aster Coller avancés, avec un statut ganglionnaire péjoratif. Cette approche multidisciplinaire sera une première nationale, rendant ainsi notre structure de pratique et de recherche médicale l'une des plateformes de prise en charge multidisciplinaire du cancer colorectal au Maroc.

No abstract

Le carcinome épidermoïde (CE) primitif du côlon est une tumeur exceptionnelle. Moins de 150 cas ont été publiés dans la littérature jusqu'à l'année 2014. Outre sa rareté, il se distingue par son association fréquente avec d'autres néoplasies digestifs. Nous rapportons l'observation d'un patient de 54 ans ayant une CE primitive du côlon. À la lumière de cette observation, on discutera les particularités anatomo-cliniques et thérapeutiques ainsi que les hypothèses étiopathogéniques de cette entité peu commune.

Background: Dumon silicone Y-stent is useful for releasing the tracheobronchial stenosis. We often encounter patients with tumors involving the carina between the bronchus to the right upper lobe and bronchus intermedius. However, there has not been ideal stenting for such cases, especially to maintain the patency of the right upper lobe bronchus. We investigated the clinical outcome in patients with malignant tracheobronchial stenosis, especially focused on the patency of right upper lobe bronchus after Y-stent placement. Method: From January 2012 until December 2018, 102 patients who had placed Y-stent on malignant tracheobronchial stenosis in our department were examined retrospectively. This study involved 73 male and 29 female. The mean age was 64 years (range, 30-91 years). Fifty-nine patients had lung cancer, 29 had esophageal cancer, and 14 had other carcinomas. All procedures were carried out in the operating room under general anesthesia, and the stents were implanted via rigid bronchoscopy. The patients were divided into two groups based on the patency of right upper bronchus: patency group (P group, n¼73) and stenosis /occlusion group (S group, n¼29). The clinicopathological features, clinical course, and the survival after stenting of the groups were compared. Result: Stents were implanted and symptoms were resolved in all cases. No operative death occurred. Stent indwelling types were only Y-stent in 69 patients and Y-stent with additional self-expanding metallic stent (SEMS) in 33. Although there was no difference between the two groups in age, gender, preoperative Hugh-Jones classification, hospitalization days, and size of Y-stent, esophageal cancer was significantly more frequent in P group. The total length of placed stent was significantly longer in S group (median 10.5cm) compared to P group (8cm) (p<0.01) and the postoperative Hugh-Jones classification (I or II) in S group (47%) was inferior compared to the P group (72%). After stent placement, 67% of the P group could be treated chemotherapy/radiotherapy to primary disease, while only 43% of the S group was received these because of their poor general condition (p ¼ 0.03).The median survival time (MST) and 1-year survival rate of the two groups was 7 months and 32% (P group), and 2 months and 17% (S group), respectively (p<0.01). Conclusion: The patency of right upper lobe bronchus after Y-stent placement affects not only the improvement of postoperative Hugh-Jones classification but also the administration of subsequent treatment to primary disease and associated to their clinical outcome.