Synthesis, Structural and Optical Characterization of II-VI Semiconductors Included in Sodalite-Type Hosts

Solid-state chemistry has been used to control both the size and the interconnection distance of small II-VI semiconductor moeities incorporated in zeolitic hosts with the sodalite-type structure. Structural characterization was carried out using X-ray Rietveld powder methods, and optical properties of these materials were also measured. These novel materials show quantum superlattice effects as evidenced by blue shifts in their optical absorption spectra.

Dose-response of the cultured bovine lens to butyl, methyl and propyl parabens

Pre-screening of cosmetic ingredients is vital for consumer safety. Previous in vivo techniques, such as the Draize test, have proved to be unreliable in predicting ocular irritancy and therefore there is a need for alternate testing methodologies. One such test is the scanning laser in vitro assay system which quantifies irritancy based on the focusing ability of the cultured bovine lens. In combination with confocal microscopy, a more thorough documentation of ocular irritancy can be achieved. This study investigates the response of cultured bovine lenses over time to butyl, methyl and propyl parabens, which are common antimicrobial agents found in cosmetic and ophthalmic products. The focusing ability of the lens was measured with an automated laser scanner over a period of 96 h. At 120 h post-treatment, the lenses were analysed by using a confocal laser scanning microscope to determine the characteristics of nuclei, and the morphology and distribution of mitochondria within the lenses. Irritancy to the three parabens was investigated at both an optical and cellular level. Each of the parabens was tested at 0.002% and 0.2%, where the 0.2% butyl paraben was found to be the most irritating.

Optical properties, mitochondria, and sutures of lenses of fishes: a comparative study of nine species

This comparative study of lenses from nine fish species consisted of seven teleosts (oscar, Astronotus ocellatus; smallmouth bass, Micropterus dolomieu; orangespotted sunfish, Lepomis humilus; Arctic char, Salvelinus alpinus; common carp, Cyprinus carpio; rainbow trout, Oncorhynchus mykiss; American eel, Anguilla rostrata) and two species representing more primitive forms (brook lamprey, Lampetra lamotteni; lake sturgeon, Acipenser fulvescens). Lens optical properties were analysed using an automated scanning laser monitor. Lens suture anatomy and the morphology and distribution of mitochondria were analysed using a confocal laser scanning microscope. Lenses of Arctic char exhibited the sharpest focus, whereas American eel lenses exhibited the poorest ability to focus and the highest amount of spherical aberration. Metabolically active mitochondria are found in lens epithelial and superficial cortical fibre cells, as in mammals. The results of the detailed study of the lens sutures show that teleost lenses exhibit "line" sutures, whereas "Y" sutures are seen in lake sturgeon lenses. Line sutures are also seen in lenses of brook lamprey and American eel. These last results contrast with the common report of "point" sutures in fish lenses.

Optical response of the cultured bovine lens; testing opaque or partially transparent semi-solid/solid common consumer hygiene products

This study determines the relative ocular lens irritancy of 16 common partially transparent or non-transparent consumer hygiene products. The irritancy was found by measuring the changes in the sharpness of focus [referred to as the back vertex distance (BVD) variability] of the cultured bovine lens using a scanning laser In Vitro Assay System. This method consists of a laser beam that scans across the lens, and a computer, which then analyses the average focal length (mm), the BVD variability (mm), and the intensity of the beam transmitted. Lenses were exposed to the 16 hygiene products and the lens' focusing ability was monitored over 192 h. The products are semi-solids or solids (e.g. gels, lotions, shampoos). They are categorized into six groups: shampoos, body washes, lotions, toothpastes, deodorant, and anti-perspirant. Damage (measured by > 1 mm BVD variability) occurred slower for the shampoos, especially in the case of baby shampoo. The results indicate that shampoos exhibit the lowest level of ocular lens toxicity (irritability) while the deodorant is the most damaging.

Suppression of post-vitrectomy lens changes in the rabbit by novel benzopyranyl esters and amides

This study reports for the first time a therapeutic modality for the suppression of posterior subcapsular cataract (PSC) formation in an animal model (rabbit) of vitrectomy. This therapeutic modality may also have the potential to attenuate/prevent the high incidence of loss of vision due to cataract formation in patients that undergo vitrectomy. Unilateral, partial vitrectomy was performed on 2.5 month old Dutch Belted rabbits with vitreous replaced by either commercially available BSS((R)) or BSS PLUS((R)) (n=16). Alternatively, vitreous was replaced with a proprietary, modified BSS PLUS((R)) irrigating solution containing 1.25 microM AL-8417 (n=12), 5.0 microM AL-12615 (n=5) or 5.0 microM AL-17052 (n=9). Age matched, non-operated rabbits were used as controls (n=16). Lenses were analysed by correlative structural (light, scanning electron microscopic and three-dimensional computer-assisted drawings) and optical (low power helium-neon laser scan) quality analysis 6 months following surgery. Results demonstrate that vitreous replacement with an irrigating solution that contains the ester-linked benzopyran, AL-8417, the amide-linked benzopyran pro-drug, AL-17052, or its active metabolite, AL-12615, prevented abnormal post-vitrectomy lens growth, or fiber formation. Focal length variability (FLV) assessments (sharpness of focus) confirmed the beneficial drug effects detected morphologically, with FLV being essentially equal to that of age-matched, non-surgical controls. In contrast, lenses of animals with vitreous replaced solely with BSS((R)) or BSS PLUS((R)) exhibited significantly higher FLV than both age-matched controls and animals that underwent vitrectomy with drug-containing irrigating solutions. The ability of AL-8417, AL-17052 and its active metabolite, AL-12615, to suppress vitrectomy-induced posterior lens fiber changes appears to reside in their unique pharmacological profile, acting as antioxidant, anti-inflammatory and cytostatic agents.