Pseudomonas aeruginosa, a ubiquitous environmental organism, is a difficult-to-treat opportunistic pathogen due to its broad-spectrum antibiotic resistance and its ability to form biofilms. In this study, we investigate the link between resistance to a clinically important antibiotic, imipenem, and biofilm formation. First, we observed that the laboratory strain P. aeruginosa PAO1 carrying a mutation in the oprD gene, which confers resistance to imipenem, showed a modest reduction in biofilm formation.We also observed an inverse relationship between imipenem resistance and biofilm formation for imipenem-resistant strains selected in vitro, as well as for clinical isolates.We identified two clinical isolates of P. aeruginosa from the sputum of cystic fibrosis patients that formed robust biofilms, but were sensitive to imipenem (MIC≤2 μg/ml). To test the hypothesis that there is a general link between imipenem resistance and biofilm formation, we performed transposon mutagenesis of these two clinical strains to identify mutants defective in biofilm formation, and then tested these mutants for imipenem resistance. Analysis of the transposon mutants revealed a role for previously described biofilm factors in these clinical isolates of P. aeruginosa, including mutations in the pilY1, pilX, pilW, algC, and pslI genes, but none of the biofilmdeficient mutants became imipenem resistant (MIC≥8 μg/ml), arguing against a general link between biofilm formation and resistance to imipenem. Thus, assessing biofilm formation capabilities of environmental isolates is unlikely to serve as a good predictor of imipenem resistance. We also discuss our findings in light of the limited literature addressing planktonic antibiotic resistance factors that impact biofilm formation.
Background: Diabetes mellitus is a major risk factor for chronic periodontitis (CP) and hyperglycemia has an important role in the enhancement of the severity of the periodontitis. It has been reported that the progression of CP causes shifting of the balance between bone formation and resorption toward osteoclastic resorption, and this will lead to the release of collagenous bone breakdown products into the local tissues and the systemic circulation. Cross-linked N-telopeptide of type I collagen (NTx) is the amino-terminal peptides of type I collagen which is released during the process of bone resorption. This study was conducted to determine the effects of nonsurgical periodontal therapy on serum level of NTx in type 2 diabetic patients
... Show MoreBack ground: During acrylic resin processing, the mold must be separated from the surface of the gypsum to prevent liquid resin from penetrating into the gypsum, and water from the gypsum seeping into the acrylic resin. For many years, tin foil was the most acceptable separating medium, and because it's difficult to apply, a tin-foil substitute is used. In this study, olive oil is used as an alternative to tin foil separating medium for first time, so the aim of the study was to evaluate its effect as a separating medium on some physical properties such as (surface roughness, water sorption and solubility) of acrylic resins denture base comparing it with those processed using tin-foil and tin foil substitute such as (cold mold seal) separat
... Show MoreEfficacy of Varnishes with: Bioactive Glass, Recaldent Technology and Silver Diamine Fluoride in Comparison with Sodium Fluoride on Tooth Surface Micro-hardness (an In Vitro Study)
Los nombres propios nombran a un ser o a un objeto, distinguiéndolo de los demás seres de su misma clase, se escriben siempre con letra mayúscula a principio de palabra. Los lingüistas hacen mayor hincapié en las divergencias de referencia, entre nombres propios y nombres comunes. Así, suele decirse que el sustantivo propio no tiene como referente ningún concepto. El asunto de la traducción de los nombres propios parecería una cuestión de gusto personal del traductor pero vemos también que en algunas épocas es más frecuente traducirlos, y en otras, por el contrario, se prefiere dejar esos nombres en su forma original, tal vez con algunas adaptaciones ortográficas. Parecería entonces cuestión de modas. Pero, eviden
... Show MoreA new, simple, accurate, fast and sensitive spectrophotometric method has been developed for the analysis of amiloride in pure and pharmaceutical formulations by continuous flow injection analysis. The method was based on the oxidation of the drug with Ce(IV)sulfate in acidic medium to formed a pinkish-red color species which determined using homemade Ayah 3SBGR x3-3D solar cell flow injection photometer. Optimum conditions were obtained using a high intensity green light emitted diode as a source. The linear dynamic range for the instrument response versus amiloride concentration was 0.0005- 10 mmol.L-1 while the L.O.D was of 9.471 ng / sample. The correlation coefficient (r) was 0.9824 while percentage linearity (r2%) was 96.50%. RSD%
... Show MoreBackground:-Atherosclerosis is a systemic disease that often affects multiple vascular distributions in a single patient. The increased prevalence of renal artery stenosis in association with coronary artery disease has been well documented.
Objectives:-To examine in detail the prevalence of renal artery stenosis in patients undergoing cardiac catheterization for suspected coronary artery disease.
Patients &methods:-Between April 2010 and February 2011, two hundred patients underwent coronary and renal angiography at the same session in Ibn Al-bitar Hospital for Cardiac Surgery. Clinical and procedural data for patients undergoing renal angiography were prospectively collected and entered into database specially designed for th
Comparative cytogenetic studies were carried out on males of two species of flour beetles, Rust flour beetle Tribolium castaneum and Confused flour beetle Tribolium confusum to investigate the karyotype. In these species, somatic chromosomes were arranged according to its length except the sex chromosomes. Results of this study showed that complete chromosomes karyotyping (2n) of T.castaneum equaled to twenty chromosomes ( 2n=20, XY ) whereas (2n) T.confusum equaled eighteen chromosomes ( 2n= 18,XY). In the two species the sex chromosome Y was the shortest chromosome and had length of average ± standard error in T.castaneum equaled to 1.500 ± 0.0 µm whereas
... Show MoreBackground: Dorsal plication on each side of the penis at the 2 and 10-o’clock positions had been a mainstay for correction of ventral penile curvature. However, because only the 12-o’clock position proved to be a nerve-free zone, dorsal plication at the 12-o’clock position can be advocated.
Objectives: To evaluate tunica albuginea plication with and without neurovascular bundle mobilization in patients with ventral penile curvature. Type of the study: A prospective study.
Methods: A 34 patients with a mean age of (4.8 ± 0.54) years, Who still