Search

La mucoviscidose, encore appelée fibrose kystique du pancréas (cystic fibrosis) ou "maladie des mucus visqueux", est une maladie génétique transmise selon le mode autosomique récessif. C'est une maladie grave ubiquitaire, très fréquente chez les caucasiens. Dans cette population blanche, les auteurs s'accordent sur une fréquence de 1 sur 2 500 nouveau-nés, correspondant à une fréquence de porteurs hétérozygotes de 1/25. Dans les autres races, la fréquence serait 20 à 40 fois moindre. Si dans les pays développés la prévalence est assez bien établie grâce à des études sans cesse renouvelées, en Afrique, particulièrement la zone subsaharienne, les données sont plutôt rares. Au Sénégal, seuls quelques cas isolés ont été rapportés dont un cas en 1983 par Fall et ses coll. Il s'agit ici d'une étude rétrospective et descriptive d'un cas clinique d'une adolescente atteinte de mucoviscidose colligé et suivi en Pédiatrie à l'Hôpital Principal de Dakar au courant de septembre-octobre 2013. Dans le cadre d'une collaboration, notre patiente a également été suivie en pneumologie pédiatrique à l'hôpital d'Enfants Albert Royer de Dakar. Le diagnostic de Mucoviscidose a été posé devant les arguments cliniques et confirmé sur la base du test de la sueur et des tests génétiques par recherche de mutation du gène CFTR. La Mucoviscidose est une pathologie très rarement diagnostiquée dans les populations noires des pays en développement. Il faut tout de même savoir y penser devant toute pathologie respiratoire trainante associée le plus souvent à une dénutrition

We consider a linear system based on a population dynamics model dependent on age, space and nonlocal boundary conditions. Note that our population dynamics model is a four-step model with a second derivative with respect to the age variable and a second derivative with respect to the space variable. Population growth at each stage depends on time and space. We prove the uniqueness and existence of a positive solution by combining the Galerkin’s variational method and the Banach’s fixed point theorem.

We consider a linear system based on a population dynamics model dependent on age, space and nonlocal boundary conditions. Note that our population dynamics model is a four‐step model with a second derivative with respect to the age variable and a second derivative with respect to the space variable. Population growth at each stage depends on time and space. We prove the uniqueness and existence of a positive solution by combining the Galerkin's variational method and the Banach's fixed point theorem. [ABSTRACT FROM AUTHOR]

We successfully cultured 36 Plasmodium falciparum isolates from blood samples of 44 malaria patients admitted to the Hôpital Principal de Dakar (Dakar, Senegal) during August–December 2014. The prevalence of isolates with in vitro reduced susceptibility was 30.6% for monodesethylamodiaquine, 52.8% for chloroquine, 44.1% for mefloquine, 16.7% for doxycycline, 11.8% for piperaquine, 8.3% for artesunate, 5.9% for pyronaridine, 2.8% for quinine and dihydroartemisinin, and 0.0% for lumefantrine. The prevalence of isolates with reduced in vitro susceptibility to the artemisinin-based combination therapy partner monodesethylamodiaquine increased from 5.6% in 2013 to 30.6% in 2014. Because of the increased prevalence of P. falciparum parasites with impaired in vitro susceptibility to monodesethylamodiaquine, the implementation of in vitro and in vivo surveillance of all artemisinin-based combination therapy partners is warranted.

In 2004, Senegal adopted the use of sulfadoxine/pyrimethamine with amodiaquine as the first-line therapy for malaria in response to increasing chloroquine resistance. In 2006, the National Malaria Control Program of [...]

Lung agenesis is a congenital anomaly usually incidentally found following respiratory tract infections. A six months old infant, second twin, is admitted for respiratory distress with hypoxia and asymmetric lung auscultation. The thoracic CT angiography shows a right pulmonary agenesis. She has recovered during the admission despite a persistent stridor whose flexible nasopharyngoscopy was normal. A long-term inhaled corticosteroid therapy was established during the follow up. Pulmonary agenesis is a rare condition for which a pulmonary radiography has to be done at the slightest doubt. [ABSTRACT FROM AUTHOR]

Copyright of Revue Africaine de Chirurgie et Spécialités is the property of Faculty of Medicine & Biomedical Sciences, University of Yaounde I, Cameroon and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To the Editor: Amplification and overexpression of the Plasmodium falciparum multidrug resistance 1 gene (Pfmdrl) have been associated with mefloquine resistance in P. falciparum malaria in Asia (1). Amplification of [...]

Background: In response to increasing resistance to anti-malarial drugs, Senegal adopted artemisinin-based combination therapy (ACT) as the first-line treatment for uncomplicated malaria in 2006. However, resistance of Plasmodium falciparum parasites to artemisinin derivatives, characterized by delayed parasite clearance after treatment with ACT or artesunate monotherapy, has recently emerged and rapidly spread in Southeast Asia. After 10 years of stability with rates ranging from 5.6 to 11.8%, the prevalence of parasites with reduced susceptibility in vitro to monodesethylamodiaquine, the active metabolite of an ACT partner drug, increased to 30.6% in 2014 in Dakar. Additionally, after a decrease of the in vitro chloroquine resistance in Dakar in 2009-2011, the prevalence of parasites that showed in vitro chloroquine resistance increased again to approximately 50% in Dakar since 2013. The aim of this study was to follow the evolution of the susceptibility to ACT partners and other anti-malarial drugs in 2015 in Dakar. An in vitro test is the only method currently available to provide an early indication of resistance to ACT partners. Results: Thirty-two P. falciparum isolates collected in 2015 in Dakar were analysed using a standard ex vivo assay based on an HRP2 ELISA. The prevalence of P. falciparum parasites with reduced susceptibility in vitro to monodesethylamodiaquine, chloroquine, mefloquine, doxycycline and quinine was 28.1, 46.9, 45.2, 31.2 and 9.7%, respectively. None of the parasites were resistant to lumefantrine, piperaquine, pyronaridine, dihydroartemisinin and artesunate. These results confirm an increase in the reduced susceptibility to monodesethylamodiaquine observed in 2014 in Dakar and the chloroquine resistance observed in 2013. The in vitro resistance seems to be established in Dakar. Additionally, the prevalence of parasites with reduced susceptibility to doxycycline has increased two-fold compared to 2014. Conclusions: The establishment of a reduced susceptibility to monodesethylamodiaquine as well as chloroquine resistance, and the emergence of a reduced susceptibility to doxycycline are disturbing. The in vitro and in vivo surveillance of anti-malarial drugs must be implemented in Senegal. [ABSTRACT FROM AUTHOR]

Background: To determine the impact of the introduction of artemisinin-based combination therapy (ACT) on parasite susceptibility, a molecular surveillance for antimalarial drug resistance was conducted on local isolates from the Hôpital Principal de Dakar between November 2013 and January 2014 and between August 2014 and December 2014. Methods: The prevalence of genetic polymorphisms in antimalarial resistance genes (pfcrt, pfmdr1, pfdhfr and pfdhps) was evaluated in 103 isolates. Results: The chloroquine-resistant haplotypes CVIET and CVMET were identified in 31.4 and 3.9 % of the isolates, respectively. The frequency of the pfcrt K76T mutation was increased from 29.3 % in 2013–2014 to 43.2 % in 2014. The pfmdr1 N86Y and Y184F mutations were identified in 6.1 and 53.5 % of the isolates, respectively. The pfdhfr triple mutant (S108N, N51I and C59R) was detected in the majority of the isolates (82.3 %). The prevalence of quadruple mutants (pfdhfr S108N, N51I, C59R and pfdhps A437G) was 40.4 %. One isolate (1.1 %) harboured the pfdhps mutations A437G and K540E and the pfdhfr mutations S108N, N51I and C59R. Conclusions: Despite a decline in the prevalence of chloroquine resistance due to the official withdrawal of the drug and to the introduction of ACT, the spread of resistance to chloroquine has continued. Furthermore, susceptibility to amodiaquine may be decreased as a result of cross-resistance. The frequency of the pfmdr1 mutation N86Y declined while the Y184F mutation increased in prevalence, suggesting that selective pressure is acting on pfmdr1, leading to a high prevalence of mutations in these isolates and the lack of specific mutations. The 50.5 % prevalence of the pfmdr1 polymorphisms N86Y and Y184F suggests a decrease in lumefantrine susceptibility. Based on these results, intensive surveillance of ACT partner drugs must be conducted regularly in Senegal. [ABSTRACT FROM AUTHOR]

Background: In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combination therapy (ACT) as the first-line treatment for uncomplicated malaria. Since the introduction of ACT, there have been very few reports on the level of Plasmodium falciparum resistance to anti-malarial drugs. An ex vivo susceptibility study was conducted on local isolates obtained from the Hôpital Principal de Dakar (Dakar, Senegal) from November 2013 to January 2014. Methods: Eighteen P. falciparum isolates were sussessfully assessed for ex vivo susceptibility to chloroquine (CQ), quinine (QN), monodesethylamodiaquine (MDAQ), the active metabolite of amodiaquine, mefloquine (MQ), lumefantrine (LMF), artesunate (AS), dihydroartemisinin (DHA), the active metabolite of artemisinin derivatives, pyronaridine (PND), piperaquine (PPQ), and, Proveblue (PVB), a methylene blue preparation, using the HRP2-based ELISA test. Results: The prevalence of isolates with reduced susceptibility was 55.6% for MQ, 50% for CQ, 5.6% for QN and MDAQ, and 0% for DHA, AS and LMF. The mean IC50 for PND, PPQ and PVB were 5.8 nM, 32.2 nM and 5.3 nM, respectively. Conclusions: The prevalence of isolates with a reduced susceptibility to MQ remains high and stable in Dakar. Since 2004, the prevalence of CQ resistance decreased, but rebounded in 2013 in Dakar. PND, PPQ and PVB showed high in vitro activity in P. falciparum parasites from Dakar. [ABSTRACT FROM AUTHOR]

In this paper, we are interested in the transport by a measurable function, of a monotone s-compact weak set valued measure, with closed convex values. We will study the integration with respect to the transported set valued measure. The main results are theorem 3.1 and theorem 3.2. [ABSTRACT FROM AUTHOR]

Background The emergence of Plasmodium falciparum resistance to artemisinin and its derivatives, manifested as delayed parasite clearance following the treatment, has developed in Southeast Asia. The spread of resistance to artemisinin from Asia to Africa may be catastrophic for malaria control and elimination worldwide. Recently, mutations in the propeller domain of the Kelch 13 (k13) gene (PF3D71343700) were associated with in vitro resistance to artemisinin and with delayed clearance after artemisinin treatment in southern Asia. The aim of the study was to characterize the genetic variability of k13 and to evaluate the molecular resistance to artemisinin for the first time in Senegal. Methods Plasmodium falciparum isolates were collected from 138 malaria patients in Dakar and its districts during the rainy season of October 2012 to January 2013 at the Hôpital Principal de Dakar. The k13 gene was amplified using nested PCR and sequenced. Results A very limited variability within the k13 gene in Senegalese P. falciparum isolates was identified. No polymorphism was detected in the six k13-propeller blades. Only two mutations, T149S (6.3%) and K189T (42.2%), and one (N) or two (NN) asparagine insertion at the codon 142 (4.7 and 6.3%, respectively) were detected in the Plasmodium/Apicomplexa-specific domain. None of the polymorphisms associated with artemisinin resistance in Southeast Asia was detected in the 138 P. falciparum from Dakar. Discussion The present data do not suggest widespread artemisinin resistance in Dakar in 2012-2013. Notably, the C580Y, R539T or Y493H substitutions that were associated with in vitro resistance or delayed parasite clearance in Southeast Asia were not observed in Dakar, nor were any of the polymorphisms observed in parasites from Southeast Asia, nor the M476I mutation that was selected in vitro with artemisinin pressure in a African parasite line. [ABSTRACT FROM AUTHOR]

In this paper, we are concerned in a non-classical boundary value problem for heat equation. More precisely, we study a linear heat equation without initial condition but with a homogeneous Dirichlet condition on the whole boundary and a nonhomogeneous Neumann condition on a part of the boundary. Under sufficient conditions on the data, we prove that the problem has a unique solution. The proof combines optimal control and controllability theories. [ABSTRACT FROM AUTHOR]

Background: Although the World Health Organization recommends replacing quinine (QN) by artesunate due to its increased efficacy and the higher tolerance to the drug in both adults and children, QN remains a first-line treatment for severe malaria, especially in Africa. Investigations of microsatellite Pfnhe-1 ms4760 polymorphisms in culture-adapted isolates from around the world have revealed that an increase in the number of DNNND amino acid motifs was associated with decreased QN susceptibility, whereas an increase in the number of DDNHNDNHNND motifs was associated with increased QN susceptibility. Methods: In this context, to further analyse associations between Pfnhe-1 ms4760 polymorphisms and QN susceptibility, 393 isolates freshly collected between October 2009 and January 2010 and July 2010 and February 2011, respectively, at the Hôpital Principal de Dakar, Senegal were assessed ex vivo for QN susceptibility, and their genes were amplified and sequenced. Results: Of the 393 Plasmodium falciparum clinical isolates collected, 145 were successfully cultured. The 145 QN IC50s ranged from 2.1 to 1291 nM, and 17 isolates (11.7%) exceed the QN reduced susceptibility threshold of 611 nM. Among the 393 P. falciparum clinical isolates, 47 different alleles were observed. The three most prevalent profiles were ms4760-1 (no = 72; 18.3%), ms4760-3 (no = 65; 16.5%) and ms4760-7 (no = 40; 10.2%). There were no significant associations observed between QN IC50 values and i) the number of repeats of DNNND in block II (p = 0.0955, Kruskal-Wallis test); ii) the number of repeats of DDNHNDNHNND in block V (p = 0.1455, Kruskal-Wallis test); or iii) ms4760 profiles (p = 0.1809, Kruskal-Wallis test). Conclusions: Pfnhe-1 ms4760 was highly diverse in parasite isolates from Dakar (47 different profiles). Three profiles (ms4760-1, ms4760-3 and ms4760-7) were predominant. The number of repeats for block II (DNNND) or block V (DDNHNDNHNND) was not significantly associated with QN susceptibility. New studies, and especially in vivo studies, are necessary to confirm the role of Pfnhe-1 ms4760 as a marker of QN resistance. [ABSTRACT FROM AUTHOR]

We consider the problem of insensitizing control when the control is subject to a finish number of linear constraint. We prove the existence of such control by solving a problem of null controllability with constraint on the control. The key of our results is an observability inequality of Carleman type adapted to the constraints. [ABSTRACT FROM AUTHOR]

The notion of sentinel was introduced by J. L. Lions Lions in order to identify parameters in problem of pollution ruled by a semilinear evolution equation. He proved that the existence of such sentinels is reduced to the solution of null controllability problem. We present here some case of simultaneous sentinels for a system of two semilinear parabolic equations. We show that such sentinels exist if only if, simultaneous null controllability with constraints on the control problems for a system governed by two heat equations holds. The key of our results is an observability inequality of Carleman type. [ABSTRACT FROM AUTHOR]

We are concerned in this paper with the existence results of the Cauchy problem for the fractional differential equation with non local conditions in ℝn: Dqx(t) = Ax(t) + f(t,x(t)), t ∈ [0,T], x(0) + g(x) = x0 where 0 < q < 1. [ABSTRACT FROM AUTHOR]

The control of a Cauchy system for an elliptic operator seems to be globally an open problem. In this paper, we analyze this problem using a regularization method which consists in viewing a singular problem as a limit of a family of well-posed problems. Following this analysis and assuming that the interior of considered convex is non-empty, we obtain a singular optimality system (S.O.S.) for the considered control problem. [ABSTRACT FROM AUTHOR]

In this work, we discuss how to get instantaneous information (at fixed t = T ∈ [0, +∞[) on pollution terms in distributed systems of incomplete data in some ecology and/or meteorology problems, using the sentinel method of Lions [J.-L. Lions, Sentinelles Pour les Systemes Distribues a Donnees Incompletes, Recherches en mathematiques appliquees RMA No. 21, Masson, Paris, 1992] with control and observation having their supports in two different open sets as by Nakoulima [O. Nakoulima, Controlabilite a zero avec contraintes sur le controle, C. R. Acad. Sci. Paris, Ser. I 339 (2004), pp. 405-410]. Here, the ecological system is affected by pollution in the boundary of the domain (e.g. a border of a lake). We verify that if the initial data are completely unknown, the sentinel is null. If there is some information on the initial data, the instantaneous sentinel naturally exists if the control set is bigger than the one where the observation may be defined. Finally, we give the characterization of the instantaneous sentinel with some remarks. [ABSTRACT FROM AUTHOR]

This work is devoted to the identification of parameters in a problem of pollution modeled by a semi-linear parabolic equation. We use the notion of sentinels introduced by J. L. Lions, (Lions, J. L. 1992 Sentinelles pour les syst?mes distribu?s ? donn?es incompl?tes. Masson, Paris.) re-visited in a more general framework. We prove the existence of such sentinels by solving a problem of null controllability with constraint on the control. The key of our results is an observability inequality of Carleman type adapted to the constraint. [ABSTRACT FROM AUTHOR]

We consider a distributed system in which the state q is governed by a parabolic equation and a pair of controls v = (h,k) where h and k play two different roles: the control k is of controllability type while h expresses that the state q does not move too far from a given state. Therefore, it is natural to introduce the control point of view. In fact, there are several ways to state and solve optimal control problems with a pair of controls h and k, in particular the Least Squares method with only one criteria for the pair (h,k) or the Pareto Optimal Control for multicriteria problems. We propose here to use the notion of Hierarchic Control. This notion assumes that we have two controls h, k where h will be the leader while k will be the follower. The main tool used to solve the null-controllability problem with constraints on the follower is an observability inequality of Carleman type which is ?adapted? to the constraints. The obtained results are applied to the sentinels theory of Lions [Masson (1992)]. [ABSTRACT FROM AUTHOR]

The problem of long-wave scattering by piecewise-constant periodic topography is studied both for a linear solitary-like wave pulse, and for a weakly nonlinear solitary wave [Korteweg–de Vries (KdV) soliton]. If the characteristic length of the topographic irregularities is larger than the pulse length, the solution of the scattering problem is obtained analytically for a leading wave in the framework of linear shallow-water theory. The wave decrement in the case of the small height of the topographic irregularities is proportional to δ2, where δ is the relative height of the topographic obstacles. An analytical approximate solution is also obtained for the weakly nonlinear problem when the length of the irregularities is larger than the characteristic nonlinear length scale. In this case, the Korteweg–de Vries equation is solved for each piece of constant depth by using the inverse scattering technique; the solutions are matched at each step by using linear shallow-water theory. The weakly nonlinear solitary wave decays more significantly than the linear solitary pulse. Solitary wave dynamics above a random seabed is also discussed, and the results obtained for random topography (including experimental data) are in reasonable agreement with the calculations for piecewise topography. [ABSTRACT FROM AUTHOR]

In this Note, we are concerned with the null-controllability of the heat problem of incomplete initial data with a source term v∈L2. Then, we look for the best of controls v in the closed convex set of admissible controls Uad of L2. By the mean of the notion of low-regret controls of Lions, we obtain a singular optimality system without any supplementary hypothesis on Uad. To cite this article: R. Dorville et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004). [Copyright &y& Elsevier]

We use the low-regret notion of Lions [1] for the control of a class of singular distributed systems: the ill-posed problems. A regularization approach is applied to the backwards heat equation, and we obtain a problem of incomplete data, for which the method of Nakoulima et al. [2] is developed. Passing to the limit, a singular optimality system is obtained for the low-regret control of the original problem without any Slater hypothesis. [Copyright &y& Elsevier]

We discuss the control of distributed systems with incomplete data following the notion of no-regret control (or, equivalently, Pareto control) used by Lions in [C. R. Acad. Sci. Paris Ser. I Math., 302 (1986), pp. 223-227] and [C. R. Acad. Sci. Paris Ser. I Math., 302 (1992), pp. 1253-1257]. We associate with the no-regret control a sequence of low-regret controls defined by a quadratic perturbation previously used by Nakoulima, Omrane, and Velin in [C. R. Acad. Sci. Paris Ser. I Math., 330 (2000), pp. 801-806]. In the first part, we prove that the perturbed system corresponds to a sequence of standard control problems and converges to the no-regret (or Pareto) control for which we obtain a singular optimality system. We give also some applications. In the second part, we show how the method can be extended to the evolution case. Equations of parabolic type, Petrowsky type, or hyperbolic type are considered. [ABSTRACT FROM AUTHOR]

In this paper, we are dealing with the ill-posed Cauchy problem for an elliptic operator. To do this, we interpret the problem as an inverse problem, and therefore a controllability problem. This point of view induces a regularization method that makes it possible, on the one hand, to characterize the existence of a regular solution to the problem. On the other hand, this method makes it possible to obtain a singular optimality system for the optimal control, without resorting to any additional assumption, such as that of non-vacuity of the interior of the sets of admissibles controls, an assumption that many analysis have had to use. From this point of view, the regularization method presented here, called controllability method, is original for the analyzed problem.