Non-doped and transition metal-doped CuO nano-powders: structure-physical properties and anti-adhesion activity relationship.

Bacterial contamination and biofilm formation generate severe problems in many fields. Among these biofilm-forming bacteria, Staphylococcus epidermidis (S. epidermidis) has emerged as a major cause of nosocomial infection (NI). However, with the dramatic rise in resistance toward conventional antibiotics, there is a pressing need for developing effective anti-biofilms. So, fabrication of copper oxide nanoparticles (NPs) is one of the new strategies to combat biofilms. Notably, doped CuO NPs in anti-biofilm therapy have become a hot spot of attention in recent years due to their physicochemical properties. In this context, the present work deals with the investigation of undoped and transition metal (TM)-doped CuO NPs (TM = Zn, Ni, Mn, Fe and Co), synthesized via the co-precipitation method. The synthesized CuO NPs are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Results consistently revealed the successful formation of CuO NPs using the co-precipitation method and confirmed that TM ions are successfully inserted into CuO crystal lattice. We found that doping changes the morphology of the CuO NPs and increases their crystallite size. The XPS results show a non-uniform distribution of the doping concentration, with a depletion or an enrichment of the NP surface depending on the element considered. Furthermore, the anti-adhesive potential of CuO NPs against S. epidermidis S61 biofilm formation is evaluated in this study by crystal violet and fluorescence microscopy assays. All synthesized NPs exhibit considerable anti-adhesive activity against S. epidermidis S61 biofilm. Interestingly, compared to undoped CuO, Fe and Ni-doped oxides show an improved activity when used at high concentrations, whereas Mn-doped CuO is the most efficient at low concentrations. This makes TM-doped CuO a promising candidate to be used in biomedical applications.

Simultaneous hydrocarbon biodegradation and biosurfactant production by oilfield-selected bacteria.

AIMS: To study the bacterial diversity associated with hydrocarbon biodegradation potentiality and biosurfactant production of Tunisian oilfields bacteria. METHODS AND RESULTS: Eight Tunisian hydrocarbonoclastic oilfields bacteria have been isolated and selected for further characterization studies. Phylogenetic analysis revealed that three thermophilic strains belonged to the genera Geobacillus, Bacillus and Brevibacillus, and that five mesophilic strains belonged to the genera Pseudomonas, Lysinibacillus, Achromobacter and Halomonas. The bacterial strains were cultivated on crude oil as sole carbon and energy sources, in the presence of different NaCl concentrations (1, 5 and 10%, w/v), and at 37 or 55°C. The hydrocarbon biodegradation potential of each strain was quantified by GC-MS. Strain C450R, phylogenetically related to the species Pseudomonas aeruginosa, showed the maximum crude oil degradation potentiality. During the growth of strain C450R on crude oil (2%, v/v), the emulsifying activity (E24) and glycoside content increased and reached values of 77 and 1.33 g l(-1), respectively. In addition, the surface tension (ST) decreased from 68 to 35.1 mN m(-1), suggesting the production of a rhamnolipid biosurfactant. Crude biosurfactant had been partially purified and characterized. It showed interest stability against temperature and salinity increasing and important emulsifying activity against oils and hydrocarbons. CONCLUSIONS: The results of this study showed the presence of diverse aerobic bacteria in Tunisian oilfields including mesophilic, thermophilic and halotolerant strains with interesting aliphatic hydrocarbon degradation potentiality, mainly for the most biosurfactant produced strains. SIGNIFICANCE AND IMPACT OF THE STUDY: It may be suggested that the bacterial isolates are suitable candidates for practical field application for effective in situ bioremediation of hydrocarbon-contaminated sites.

Isolation and characterization of Halomonas sp. strain C2SS100, a hydrocarbon-degrading bacterium under hypersaline conditions.

AIMS: To isolate and characterize an efficient hydrocarbon-degrading bacterium under hypersaline conditions, from a Tunisian off-shore oil field. METHODS AND RESULTS: Production water collected from 'Sercina' petroleum reservoir, located near the Kerkennah island, Tunisia, was used for the screening of halotolerant or halophilic bacteria able to degrade crude oil. Bacterial strain C2SS100 was isolated after enrichment on crude oil, in the presence of 100 g l(-1) NaCl and at 37 degrees C. This strain was aerobic, Gram-negative, rod-shaped, motile, oxidase + and catalase +. Phenotypic characters and phylogenetic analysis based on the 16S rRNA gene of the isolate C2SS100 showed that it was related to members of the Halomonas genus. The degradation of several compounds present in crude oil was confirmed by GC-MS analysis. The use of refined petroleum products such as diesel fuel and lubricating oil as sole carbon source, under the same conditions of temperature and salinity, showed that significant amounts of these heterogenic compounds could be degraded. Strain C2SS100 was able to degrade hexadecane (C16). During growth on hexadecane, cells surface hydrophobicity and emulsifying activity increased indicating the production of biosurfactant by strain C2SS100. CONCLUSIONS: A halotolerant bacterial strain Halomonas sp. C2SS100 was isolated from production water of an oil field, after enrichment on crude oil. This strain is able to degrade hydrocarbons efficiently. The mode of hydrocarbon uptake is realized by the production of a biosurfactant which enhances the solubility of hydrocarbons and renders them more accessible for biodegradation. SIGNIFICANCE AND IMPACT OF THE STUDY: The biodegradation potential of the Halomonas sp. strain C2SS100 gives it an advantage for possibly application on bioremediation of water, hydrocarbon-contaminated sites under high-salinity level.

Secondary chronic myelomonocytic leukemia with monosomy 7 after successful treatment of acute promyelocytic leukemia.

Current APL chemotherapy protocols usually include high-dose anthracyclines, mitoxantrone, and epipodophillotoxins, which are topoisomerase II inhibitors of high leukemogenic potential. In the last years, several case reports of myelodysplastic syndrome (MDS) or AML (different from APL), occurring during the course of APL have been made. We report herein a first case of CMML with monosomy 7 occurring after treatment of APL.

Manifestations ophtamologiques au cours du syndrome d'Apert : a propos d'un cas

Introduction : Parmi les craniostenoses; le syndrome d'Apert demande la collaboration de plusieurs specialistes; pour sauver ce qui peut l'etre de la fonction visuelle des patients et permettre un developpement cerebral le plus proche de la normale. Observation : Nous presentons le cas d'une jeune suivie et traitee depuis son jeune age pour un syndrome d'Apert. Elle a subi plusieurs interventions successives pour garder a un age assez avance une fonction visuelle appreciable a 3/10. Les modifications anato- miques ont ineluctablement influe sur l'etat visuel de la patiente avec une myopie forte; un astigmatisme relativement important et une atrophie papillaire partielle.Discussion : D'origine genetique; le syndrome d'Apert est du a une mutation allelique du recepteur 2 d'un facteur fibroblastique. Les signes de souffrance cerebrale sont inevitables; et l'atrophie optique relative represente la sequelle fonctionnelle principale. Conclusion : Une prise en charge de longue haleine est necessaire dans le syndrome d'Apert pour esperer sauver une fonction visuelle utile

[Percutaneous mitral commissurotomy. 5-year results]. / La commissurotomie mitrale percutanee. Resultats a 5 ans.

Long-term results of percutaneous mitral commissurotomy were evaluated in 410 patients with mean age of 31 years (18 to 68 years). 48% of patients had mean thickened leaflets, 35% had calcified valves and 17% had flexible leaflets and subvalvular apparatus. Procedure was performed with a double balloon in 57% and with Inoue's balloon in 43% patients. A good immediate results was obtained in 77% of patients. A good result was defined as a mitral valve area > or = 1.5 cm2 without mitral regurgitation. Clinical follow-up concern 378 patients. The actuarial 5 years rate were 84% in our serie, without surgery or new percutaneous mitral commissurotomy and good functional results (NYHA class I or II) were 71%. Valvular anatomy, immediate results (mitral valve area), history of mitral commissurotomy, old patients, atrial fibrillation can influence strongly the results.

[Acute dissection of the ascending aorta complicating aortic coarctation successfully treated with surgery]. / Dissection aiguë de l'aorte ascendante compliquant une coarctation de l'aorte opérée avec succès.

Vascular complications and arterial hypertension are major risk factors in the evolution of disease connected with coarctation of the aorta. Supra- and sub-stenotic aortic aneurysms are classical findings, whereas a dissecting aneurysm is a rare occurrence. In this study, we report on a case of acute dissection of the ascending aorta complicating a poorly followed-up coarctation of the aorta in a ten-year-old girl. The diagnosis, determined by X-ray of the thorax, was confirmed by echocardiography and magnetic resonance imaging. The first operative stage consisted of treating the aneurysm. After resection of the latter, an impregnated dacron prosthesis was inserted in termino-terminal. The immediate result is satisfactory, and a second operation is planned for the aortic coarctation.

[Sideropenic dysphagia]. / La dysphagie sidéropénique.

Ten typical cases of sideropenic dysphagia over four years reported and clinical, biological, endoscopic and radiological signs are studied. The authors stress the value of oesophagal opacification for diagnosis. The particularities of our study are the relative high frequency of the disease in Tunisia and the unusual attack in two black patients.