Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer.

The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed against Candida albicans ATCC 10231 (ATCC-American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active against Candida albicans biofilm embedded cells.

Structural properties of silver doped hydroxyapatite and their biocompatibility.

The aim of this study was to obtain a novel hydroxyapatite-based material with high biocompatibility. The structural properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The X-ray diffraction studies revealed the characteristic peaks of hydroxyapatite in each sample. Other phases or impurities were not observed. The scanning electron microscopy observations suggest that the doping components have no influence on the surface morphology of the samples, which reveals a homogeneous aspect of the synthesized particles for all samples. The presence of calcium (Ca), phosphor (P), oxygen (O) and silver (Ag) in the Ag:HAp is confirmed by energy dispersive X-ray (EDAX) and X-ray Photoelectron Spectroscopy analyses. Nanocrystalline silver doped HAp stimulated viability and potentiated the activation of murine macrophages.

Creatinine biomaterial thin films grown by laser techniques.

Creatinine thin films were synthesised by matrix assisted pulsed laser deposition (PLD) techniques for enzyme-based biosensor applications. An UV KrF* (lambda=248 nm, tau approximately 10 ns) excimer laser source was used for the irradiation of the targets at incident fluence values in the 0.3-0.5 J/cm2 range. For the matrix assisted PLD the targets consisted on a frozen composite obtained by dissolving the biomaterials in distilled water. The surface morphology, chemical composition and structure of the obtained biomaterial thin films were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, and electron dispersive X-ray spectroscopy as a function of the target preparation procedure and incident laser fluence.

[Assessment of compressive optic neuropathy in hipofizar tumors]. / Evaluarea neuropatiei optice de compresie in tumorile hipofizare- aspecte morfologice calitative si cantitative.

PURPOSE: Assessment of optic nerve head configuration in eyes with compressive optic neuropathy due to pituitary tumors--morphological aspects of "band atrophy" (documented by fundus biomicroscopy and digital stereo disc photography) and quantitative analysis of topographic changes (testing the abilities of HRT and OCT in detection and analysis the specific pattern of nerve fiber layer loss in chiasmal compression). MATERIAL AND METHODS: Optic disc morphological assessment of compressive optic neuropathy in 56 patients with pituitary macroadenomas (documented by direct ophthalmoscopy, fundus biomicroscopy using Volk lens of 90 degrees and digital stereo disc photography using Zeiss Visucam digital camera). Stereometric analysis of "band atrophy" using HRT in 9 cases and OCT in 5 cases. RESULTS: The optic disc morphology evaluation of the 54 patients showed bilateral "band atrophy" in 7 cases, different evolutive aspects (temporal pallor, global pallor, optic disc cupping) in 29 cases and normal configuration in 5 cases. HRT evaluation: overestimation of rim parameters and underestimation of cup parameters; reduction of the RNFL thickness and RNFL cross sectional area in 6 cases; reduction of HVC values in 6 eyes and positive values in 1 eye. OCT analysis of the Avg. thickness: outside normal limits values in 6 eyes and borderline values in 4 eyes. CONCLUSIONS: HRT quantified RNFL thickness reduction for the long standing pituitary macroadenomas, its sensitivity increasing with the advanced stage of the compression, but lacking OCT's specificity. OCT is the election technique for documenting RNFL loss in compressive optic neuropathy due to pituitary tumors, more objective than conventional methods, especially in the process of postoperative management (subtle structural alterations being early detected before functional loss recordings.

[Isovolemic hemodilution--a treatment method for central retinal vein obstruction]. / Hemodilutia izovolemica--metoda de tratament a obstructiei de vena centrala a retinei.

OVCR--is a vascular disease of the posterior pole of the eye, witch leads usually, to a significant decrease of the visual acuity. The actual management of the disease is still inefficient of the functional recovery of those patients. Among the medical treatment methods, is also the isovolemic hemodilution, witch must be established only after a thorough cardio-vascular and renal examination. The present study shows an increase of the visual acuity in the patients treated with isovolemic hemodilution followed by LASER Argon photocoagulation.

[Sulodexide treatment in retinal vein obstructions]. / Tratamentul cu sulodexid în obstructiile venoase retiniene.

Retinal vein occlusion (RVO) represents one of the most frequent vascular disorders of the posterior pole. RVO treatment is disappointing because a great number of patients remains with a reduced visual acuity; the visual acuity is the functional test which shows the treatment efficacity. The study group of patients was treated with sulodexid, a therapeutic agent with thrombolytic and fibrinolytic action; sulodexid was associated with laser photocoagulation where it was required. Study's results point out efficiency only for those cases treated precociously between 48 to 72 hours from the outset.