Biomedical subjects

Ahmed Sallam

Publications and source records attributed to Ahmed Sallam.

3 recordsLinked to original sources

PubMed2006

Endogenous Candida endophthalmitis.

Intraocular Candida infections, although uncommon, represent an important clinical problem owing to the potential for visual loss, which can be bilateral. Candida chorioretinitis and endophthalmitis are complications of systemic candidiasis with extension of the fungal pathogens to the uvea and retina. Early diagnosis and prompt management significantly affect the visual prognosis for these patients. This review evaluates the current literature on Candida endophthalmitis and includes discussion on presentation, diagnosis and management strategies. New systemic and intravitreal antifungal agents are also reviewed in the context of the management of intraocular fungal infection.

Antifungal Agents↗

PubMedDate not supplied

Isolation and characterization of gram-positive cyanophycin-degrading bacteria-kinetic studies on cyanophycin depolymerase activity in aerobic bacteria.

This study is the first report on the extracellular degradation of cyanophycin (CGP) by Gram-positive bacteria. Three different Gram-positive bacteria were isolated from forest soil that were able to utilize CGP as the sole carbon source for growth. The isolates were assigned to species of the genera Bacillus and Micromonospora. From one of the isolates, which was taxonomically affiliated as Bacillus megaterium strain BAC19, the extracellular CGP depolymerase (extracellular CGPase; CphEBm) was purified to electrophoretic homogeneity by fast protein liquid chromatography and affinity binding to an arginine-agarose column. The purified enzyme was specific for hydrolytic cleavage of CGP, and inhibitor studies indicated that CphEBm is a serine-type peptidase. As CGP degradation products, (beta-Asp-Arg)2 tetrapeptides in addition to beta-Asp-Arg dipeptides occurred, which were identified by electrospray ionization mass spectrometry analysis. Furthermore, a novel quantitative enzyme assay was developed for kinetic studies on CGP depolymerases. For CphEBm, as well as for the extracellular CGPase of Pseudomonas anguilliseptica strain BI (CphEPa), KM values of 2.2 and 1.0 microM, respectively, for CGP were determined.

Bacillus↗

PubMedDate not supplied

Sperm velocity and morphology, female characteristics, and the hypo-osmotic swelling test as predictors of fertilization potential: experience from the IVF model.

OBJECTIVE: To determine, among the following variables, the predictors of sperm fertilization potential of a given semen sample: sperm count, eight sperm velocity characteristics determined by computer-assisted semen analysis, the sperm morphology score determined by strict criteria, and the hypo-osmotic swelling (HOS) test, using the IVF model. DESIGN: Data from 58 couples attending the assisted conception unit for conventional IVF treatment were analyzed retrospectively by simple linear regression and multiple stepwise regression analysis, taking the fertilization rate as the dependent factor. RESULTS: The mean sperm velocity and the strict sperm morphology assessment were the only parameters showing significant correlation with the fertilization rate. A minimum sperm velocity of 13 microm/s and a minimum strict sperm morphology of 2% were necessary to achieve fertilization in 50% of the oocytes. The results of the HOS test did not correlate with the fertilization rate. An equation was devised to calculate the expected fertilization rate based on the mean sperm velocity and the strict morphology score, and can be used to counsel patients prior to assisted conception. CONCLUSIONS: The mean sperm velocity and strict sperm morphology evaluation are good predictors of fertilization potential, but the HOS test is not.

Adult↗