Early assessment of genotypic variation in growth and nitrogen fixation in Faidherbia albida/rhizobium symbiosis

To enhance the benefits from N2-fixing symbiosis in low nitrogen fixers such as Faidherbia albida, knowledge is needed on how genotypes of both the host and its bacterial partner interact to influence N fixation-related traits of the host legume. A greenhouse experiment was carried out to investigate the variability of several traits with respect to provenance, rhizobial strain and their interactions. Four West African provenances of F. albida were inoculated with five proven effective strains and grown for two months. Provenance x strain interactions were significant only for shoot N concentration (%N) and total shoot N uptake but their contributions to total phenotypic variances were rather low (6-10%). Because of large differencesamong provenances in growth performance the host genotype showed the greatest contribution (70.7%) to the variability in total shoot N uptake. Variability in %N in turn was mostly related to strain effectiveness (71.2%).These results suggest that under conditions of N deficiency, growth performance and shoot N concentration provide reliable selection criteria when screening for improved N2-fixation in F. albida.Keywords: rhizobia, Faidherbia, provenance, variability, interaction, N2-fixatio

Prevalence et facteurs associes a l’halitose buccale : Etude dans une population generale senegalaise

Introduction: Halitosis is a common complain among dental patients, chronic among 50% of the adult population, and of oral origin in 90% of the cases. The objective of this study was to evaluate the prevalence and related factors of oral halitosis among a senegalese population. Material and method: This was a transversal descriptive study of 396 Senegalese adults using a 24-point self-assessment questionnaire on halitosis. All subjects were examined to estimate the organoleptic means and to measure the Sulfur Volatile Compounds (SVC), using a halimeter. Halitosis was diagnosed when the level of sulfur volatile Compound was ≥125 ppb and the organoleptic score ≥ 2. Data were statistically analyzed using the chi2 test. Results: The global prevalence of halitosis was 32.3 %. The difference was not statistically significant between male and female. Among the 396 patients suffering from bad breath, 128 had a permanent halitosis and 52 had a physiological halitosis. The means of the organoleptic scores were 3.12 and that of the (SVC) were 273.9 ppb. Conclusion: The results of the study showed a relation between the organoleptic tests and the level of sulfur volatile compounds (SVC). Keywords: Halitosis, organoleptic tests, sulfur volatile compound, epidemiology, and self-assessment

Complications des otites moyennes chroniques

Objectif de l’étude : Rapporter la fréquence des complications des otites moyennes chroniques et présenter notre expérience dans leur prise en charge.Matériel et méthodes : Etude rétrospective concernant la période allant du 1er janvier 2000 au 31 décembre 2009. Les complications ont été réparties en 2 grands groupes : extracrâniennes et intracrâ-niennes.Résultats : 57 patients sur 350 reçus pour OMC ont présenté une complication, soit une fréquence de 18,38 %. Le cholestéatome était le plus grand pourvoyeur de ces complications (84,2%). Dix-neuf patients présentaient plus d’une complication, soit au total 76 cas. Les complications extracrâniennes ont été les plus fréquentes, 63 cas (83%), dominées par la mastoïdite extériorisée profuse (68,3%). Les complications intracrâniennes au nombre de 13 (17%) étaient dominées par la méningite purulente otogène (46,2%). La mastoïdectomie associée à une antibiothérapie à large spectre, occupait une place im-portante dans la prise en charge de ces complications. Elle a été réalisée chez 45 patients (79%). La mortalité a été estimée à 3,5% (2 cas de décès). Un drainage neurochirurgical a été effectué dans 4 cas (8,6 %).Conclusion : Cette étude se caractérise par un taux de complications d’OMC plus élevé que ceux rappor-tés dans la littérature, ainsi que par la prédominance des formes étendues et des associa-tions de complications chez un même patient.Mots clés : Otite moyenne chronique, Complications, Cholestéatome.The objective of this study : was to report the frequency and our experience of management of complications of chronic otitsmedia.Methods : We conducted a retrospective study covering 10 years period (from 1st January 2000 to 31 December 2009). Complications were divided into 2 groups: extracranial and intracranial.Results : Among 350 patients received for chronic otitis media, 57 presented complications, such as a rate of 18.38%. Cholesteatoma was the largest provider of these complications in order of 84.2%. Nineteen (19) patients had more than one complication. So, a total of 76 cases of complications were listed. Subperiostal mastoiditis was the most common findings, 68.3% of the extracranial complications. The intracranial complications, (17%), were domi-nated by otogenic purulent meningitis (46.2%). Radical mastoïdectomy with broad spectrum antibiotics occupied an important place in the management of these complications, performed in 45 patients (79%). Neurosurgical drainage was performed in 4 cases (8.6%). Mortality was estimated at 3.5% (2 deaths).Conclusion : COCM are characterized, in this study, by an elevated rate compared to that reported in the literature, the prevalence of extended forms and associations of complications in the same patient.Keys words : Chronic otitis media, Complications, Cholesteatoma

Myringoplastie par la technique des boutonnières

Introduction : La réparation des lésions tympaniques et ossiculaires au cours de l’otite chronique fait appel à plusieurs procédés bien codifiés par leurs utilisateurs.Le but de ce travail est de rapporter nos résultatsde myringoplastie par la technique des boutonnières, chez des patients porteurs de séquelles d’otite moyenne chronique non cholestéatomateuse.Patients et méthode : Etude rétrospective concernant 49 patients opérés consécutivement de tympanoplastie pour otite moyenne chronique non cholestéatomateuse, entre janvier 2003 et décembre 2009, sélectionnés parmi 140 autres opérés de tympanoplasties selon d’autres procédés. Le temps de réparation de la membrane tympanique (Myringoplastie) a été effectué par la technique d’amarrage antérieur du greffon, technique dite des boutonnières. Les critères d’évaluationétaient l’état du tympan à la dernière consultation, le rinne moyen post opératoire ou rinne résiduel et le gain moyen auditif. Le gain auditif était représenté par la différence entre le rinne pré-opératoire et le rinne post opératoire et tous les paramètres fonctionnels appréciés sur les fréquences 500, 1000 et 2000 hertz.Résultats : L’âge moyen était de 29 ans avec des extrêmes de 8 et 64 ans. La perforation tympanique était importante, centrale ou subtotale dans 32 cas (65,30%), avec une ancienneté remontant à l’enfance dans 19 cas (38,77%). L’oreille controlatérale était porteuse d’une pathologie dans 23 cas (47%). Le rinne moyen pré-opératoire était de 37,04 dB. Avec un recul moyen de 26 mois, la restauration anatomique du tympan en position normale était notée dans 35 cas (71,42 %). Le taux de reperforation a été estimé à 20,4% (10 cas), tandisque la médialisation a été observée dans 2 cas (4,08%), la latéralisation dans 1 cas (2,04%), le blunting ou comblement de l’angle antérieur tympano-méatal dans 1 cas (2,04%). Nous avons noté un rinne moyen post opératoire de 20,38 dB avec un gain moyen post opératoire de 14dB.Conclusion : Les résultats obtenus dans cette première série de myringoplastiepar la technique des boutonnières ont été modestes, mais améliorés dans le temps avec la maitrise de la technique opératoire et des facteurs de risque d’échec représentés ici par l’ancienneté, l’importance et l’évolutivité des lésions.Mots clés : Otite chronique, Myringoplastie, Technique des boutonnières.Objective : Several methods well codified by their users had been described for the repairing of tympanic and ossicular damage during chronic otitis media. The aim of this study was to report our results of myringoplasties by the technic of buttonholes procedure, in patients with sequelae of non chlesteatoma chronic otitis media.Patients and methods : A retrospective study on 49 patients, with sequalea of non cholesteatoma chronic otitis media, operated consecutively of myringoplasty by the technic of buttonholes, between january 2003 and december 2009, was caried out. The patients had been selected among 140 others operated throught others procedures. The criteria of evaluation were the ear drum’s aspect at the last clinical examination, the average air bone gap and the average hearing gain established as the difference between pre opérative and post operative air bone gap. The parameters for the post operative functional outcome had been assessed on the frequencies 500, 1000 and 2000 kHz.Results: The average age was 29 years and ranged from 8 to 64. The tympanic membrane’s perforation was important, central or subtotal in 32 cases (65,30%), with a long term évolution dating back to childhood in 19 cases (38,77%). Pathological disease was noticed in the controlateral ear in 23 cases (47%). The average pre operative air bone gap was 37.04 dB. After a mean follow up of 26 month, the succeful rate of closure of the tymapanic membrane, in the normal position, was 71,42%. The recidive of perforation (reperforation) was estimated at 20,4% (10 cases), whereverthe medialization was observed in 2 cases (4,08), lateralization and the blunting or filling the anterior tympano-méatal angle in respectively 1 case (2,04%). We noted an average post oprative air bone gap of 20,38 dB with an average hearing gain of 14 dB.Conclusion: The results obtained in this first round of myringoplasty with buttonhole procedure were modest, but improved over time withthe mastery of the surgery technic and risks factors of failure represented here by the age, size and scalabillity of the lesions.Keyswords : Chronic otitis media, Myringoplasty, Technic of buttonhole

Counter-current chromatography for the separation of terpenoids: A comprehensive review with respect to the solvent systems employed

Copyright @ 2014 The Authors.This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Natural products extracts are commonly highly complex mixtures of active compounds and consequently their purification becomes a particularly challenging task. The development of a purification protocol to extract a single active component from the many hundreds that are often present in the mixture is something that can take months or even years to achieve, thus it is important for the natural product chemist to have, at their disposal, a broad range of diverse purification techniques. Counter-current chromatography (CCC) is one such separation technique utilising two immiscible phases, one as the stationary phase (retained in a spinning coil by centrifugal forces) and the second as the mobile phase. The method benefits from a number of advantages when compared with the more traditional liquid-solid separation methods, such as no irreversible adsorption, total recovery of the injected sample, minimal tailing of peaks, low risk of sample denaturation, the ability to accept particulates, and a low solvent consumption. The selection of an appropriate two-phase solvent system is critical to the running of CCC since this is both the mobile and the stationary phase of the system. However, this is also by far the most time consuming aspect of the technique and the one that most inhibits its general take-up. In recent years, numerous natural product purifications have been published using CCC from almost every country across the globe. Many of these papers are devoted to terpenoids-one of the most diverse groups. Naturally occurring terpenoids provide opportunities to discover new drugs but many of them are available at very low levels in nature and a huge number of them still remain unexplored. The collective knowledge on performing successful CCC separations of terpenoids has been gathered and reviewed by the authors, in order to create a comprehensive document that will be of great assistance in performing future purifications. © 2014 The Author(s)

Experimental Evolution of an Oncolytic Vesicular Stomatitis Virus with Increased Selectivity for p53-Deficient Cells

Experimental evolution has been used for various biotechnological applications including protein and microbial cell engineering, but less commonly in the field of oncolytic virotherapy. Here, we sought to adapt a rapidly evolving RNA virus to cells deficient for the tumor suppressor gene p53, a hallmark of cancer cells. To achieve this goal, we established four independent evolution lines of the vesicular stomatitis virus (VSV) in p53-knockout mouse embryonic fibroblasts (p53−/− MEFs) under conditions favoring the action of natural selection. We found that some evolved viruses showed increased fitness and cytotoxicity in p53−/− cells but not in isogenic p53+/+ cells, indicating gene-specific adaptation. However, full-length sequencing revealed no obvious or previously described genetic changes associated with oncolytic activity. Half-maximal effective dose (EC50) assays in mouse p53-positive colon cancer (CT26) and p53-deficient breast cancer (4T1) cells indicated that the evolved viruses were more effective against 4T1 cells than the parental virus or a reference oncolytic VSV (MΔ51), but showed no increased efficacy against CT26 cells. In vivo assays using 4T1 syngeneic tumor models showed that one of the evolved lines significantly delayed tumor growth compared to mice treated with the parental virus or untreated controls, and was able to induce transient tumor suppression. Our results show that RNA viruses can be specifically adapted typical cancer features such as p53 inactivation, and illustrate the usefulness of experimental evolution for oncolytic virotherapy

The evolutionary significance of polyploidy

Polyploidy, or the duplication of entire genomes, has been observed in prokaryotic and eukaryotic organisms, and in somatic and germ cells. The consequences of polyploidization are complex and variable, and they differ greatly between systems (clonal or non-clonal) and species, but the process has often been considered to be an evolutionary 'dead end'. Here, we review the accumulating evidence that correlates polyploidization with environmental change or stress, and that has led to an increased recognition of its short-term adaptive potential. In addition, we discuss how, once polyploidy has been established, the unique retention profile of duplicated genes following whole-genome duplication might explain key longer-term evolutionary transitions and a general increase in biological complexity