Steroidal and nonsteroidal antiinflammatory medications can improve photoreceptor survival after laser retinal photocoagulation.

Objective: To determine whether methylprednisolone or indomethacin can enhance photoreceptor survival after laser retinal injury in an animal model.

Design: Experimental study.

Participants: Twenty rhesus monkeys.

Production of a uniform cellular injury by raster scanning of cells for the study of laser bioeffects.

Efforts to understand laser bioeffects in cells and tissues have been hindered by a nonuniform cellular response of the specimen, resulting in graded biochemical effects. In addition, the small beam diameters of commonly used lasers limit the number of cells expressing a response to numbers inadequate for the study of biochemical effects. For a limited emission power, expansion of the beam diameter reduces the irradiance, thus requiring longer exposure durations to produce a cellular response.

Lecithin:retinol acyltransferase in ARPE-19.

The purpose of this study is to investigate if a readily available cell line (APRE-19) may be used to study in vitro function of visual cycle enzymes such as lecithin:retinol acyltransferase (LRAT). Cells incubated with exogenous retinol accumulated intracellular all-trans retinol and all-trans retinyl ester. Membrane proteins from ARPE-19 exhibited LRAT activity, which was inhibited by an LRAT inhibitor, retinyl bromoacetate (RBA).

Laser-induced macular holes demonstrate impaired choroidal perfusion.

Purpose: To evaluate choroidal perfusion following creation of a laser-induced macular hole in a nonhuman primate model.

Methods: Six rhesus monkeys underwent macular exposures delivered by a Q-switched Nd:YAG laser. The lesions were evaluated with fluorescein angiography and indocyanine green angiography using scanning laser ophthalmoscopy.

Cytoprotection against thermal injury: evaluation of herbimycin A by cell viability and cDNA arrays.

Herbimycin A (HA), a known inducer of the heat shock response, was investigated for its ability to increase survival of a human cell line following thermal injury. Its effect on transcriptional activity was also assessed with cDNA arrays to provide new targets for cytoprotection. Pretreatment with at least 0.

Gene expression profiling of the response to thermal injury in human cells.

The genetic response of human cells to sublethal thermal injury was assessed by gene expression profiling, using macroarrays containing 588 complementary known genes. At 1, 4, 8, and 24 h following thermal injury, RNA was isolated, and a cDNA copy was generated incorporating (33)P and hybridized to Atlas arrays. About one-fifth of the genes on the membrane exhibited a significant elevation or depression in expression (>/=2-fold) by 4 h posttreatment.

Apoptosis and accidental cell death in cultured human keratinocytes after thermal injury.

The respective roles of apoptosis and accidental cell death after thermal injury were evaluated in normal human epidermal keratinocytes. By coupling the LIVE/DEAD fluorescence viability assay with the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and ultrastructural morphology, these two processes could be distinguished. Cells were grown on glass coverslips with a microgrid pattern so that the results of several staining procedures performed sequentially could be visualized in the same cells after heating at temperatures of up to 72 degrees C for 1 second.

Survival of human epidermal keratinocytes after short-duration high temperature: synthesis of HSP70 and IL-8.

Thermal injury by short pulses (1-30 s) of relatively high temperature (50-68 degrees C) was investigated in normal human epidermal keratinocytes (NHEK). NHEK were cultured on plastic cover-slips and dipped in medium held at various temperatures. Survival assessed by methylthiazol tetrazolium reduction assay at 6 days postheating demonstrated an inverse time-temperature relationship that indicated that most cells could survive after a 1-s, 60 degrees C exposure or a 30-s, 55 degrees C exposure.

Accelerated healing of laser-injured rabbit retina by basic fibroblast growth factor.

Purpose: To improve the outcome of injured retina, human recombinant basic fibroblast growth factor (bFGF) was examined for its ability to accelerate healing in laser-injured New Zealand Red rabbits.

Methods: A multi-line argon laser (454 to 514 nm) was used to produce lesions near subretinal hemorrhaging levels. Within 30 minutes after irradiation, eyes were intravitreally injected directly above the lesions with 10 microliters vehicle or 10 micrograms of bFGF in 10 microliters of vehicle.

Retinal cell and photoreceptor transplantation between adult New Zealand red rabbit retinas.

Adult New Zealand Red (NZR) rabbits were used to determine if the techniques developed in the rat to transplant sheets of photoreceptors could be adapted to larger eyes of the rabbit. Adult donor NZR rabbit retina was cut into small strips, oriented, and drawn up in a small and flat polyethylene tube. By transscleral approach, donor retina was correctly oriented and gently placed into the subretinal space of host retinas that were previously ablated of photoreceptors by intravitreal injection of hemoglobin.

Serum-free culture of porcine and rabbit corneal epithelial cells.

To better define the growth requirements for corneal epithelial cells, methods for serum-free culture were established. Sheets of corneal epithelium from eyes of swine and rabbits were obtained by dispase treatment of corneal buttons, and single cells and small clumps were obtained by further dissociation with trypsin/EDTA. Growth of cells with epithelial-like morphology was readily achieved in low calcium MCDB 153 medium containing epidermal growth factor, insulin, hydrocortisone, and bovine pituitary extract.

Morphologic alterations in rat retina after hypervolemic infusion of cross-linked hemoglobin.

Hypervolemic infusion in rats of bis (3,5-dibromosalicyl) fumarate cross-linked hemoglobin (DBBF-Hb) to 40-60% of blood volume produced histologic lesions in retina which were not observed in rats similarly infused with human serum albumin or lactated Ringer's solution. Rats treated with 40% DBBF-Hb, exhibited intermittent zones of dense retinal pigmented epithelium while 60% DBBF-Hb animals exhibited severe inner retinal edema and retinal pigmented epithelium vacuolization, large focal zones of photoreceptor outer segment disruption and in one animal, subretinal hemorrhage. Light microscopic immunocytochemical evaluation of retinas with antibodies directed to human hemoglobin and albumin, showed the presence of both hemoglobin and albumin in this tissue.

Liver and kidney injury after administration of hemoglobin cross-linked with bis(3,5-dibromosalicyl) fumarate.

Human hemoglobin cross-linked between the alpha chains with bis (3,5-dibromosalicyl) fumarate (DBBF-Hb) was exchange transfused in swine and the histomorphologic changes were evaluated. Following exchange, animals were euthanized and tissues were taken for light and electron microscopy at 7.5 hours and days 1, 4, 7, and 15.

Myopathic alterations in extraocular muscle of rats subchronically fed pyridostigmine bromide.

To determine if alterations in extraocular muscle morphology occur after subchronic oral administration of pyridostigmine bromide, rats were continuously fed 90 mg/kg in meal and examined at 1, 2, 4, 7, and 15 days. Within the first day, blood acetylcholinesterase activity was reduced by 87% and remained inhibited by 74-91% during the study. Light microscopy demonstrated that by day 1 approximately 3% of the extraocular myofibers were shrunken and invaded by inflammatory cells.

Myopathic changes in diaphragm of rats fed pyridostigmine bromide subchronically.

To determine if alterations in muscle morphology occur after subchronic oral administration of pyridostigmine bromide, rats were fed 90 mg/kg continuously in meal and examined at 1, 2, 4, 7, and 15 days. Within the first day, cholinesterase activity was reduced by 87% and remained inhibited by 74-91% for the entire course of the feeding. Light microscopy demonstrated that by the first day approximately 1 in 100 myofibers was shrunken and contained centralized nuclei.

Removal of bacteria from blood by charcoal hemoperfusion.

E. coli bacteria were successfully removed from contaminated RBC/plasma by using a special matrix of micro-encapsulated albumin activated charcoal (ACAC). Efficacy of removing the bacteria was directly related to the amount of time the contaminated blood was in contact with the charcoal.

Laser induced thermal injury of rabbit cornea and treatment with anti-inflammatory agents.

A moderately severe thermal injury of the central cornea of 48 Dutch-belted rabbit eyes was produced with a carbon (CO2) laser. The lesions were photographed with a slit lamp (SL) camera immediately following the injury and at 1, 2, 4, 7, 14, 21, 30 and 60 days after the exposure. Lesion size, opaqueness, and depth were graded clinically by SL biomicroscopy at the same intervals.

Morphologic effects on the retina of massive exchange transfusion with stroma-free hemoglobin solution.

Retinal morphology serves as an extremely sensitive end point to hypoxic and ischemic conditions manifested by circulatory perturbations. Therefore, the effect of massive transfusion of stroma-free hemoglobin solution (SFHS) on retinal morphology of rats was evaluated. Seventy-three rats were divided into three groups.

Observations on preadipocytes and their distribution patterns in rat adipose tissue.

Microscopic examination of adipocytes isolated from adult rat epididymal adipose tissue revealed numerous small cells (less than 10 micron) morphologically similar to larger adipocytes. These small adipocytes appear identical to a new classification of adipose cells termed preadipocytes. Electron micrographs of these preadipocytes revealed examples of cells less than 10 micron in diameter in various stages of maturation and lipid accumulation.