Barros, P.S.M., C.F. Padovani, V.V. Silva, and S.B.M. Barros (2001). Oxidative stress after lens phaco-emulsification in dogs. IOVS 42(4): S13.
Descriptors: methods and techniques, sense organs, sensory reception, anterior chamber paracentesis, diagnostic method, applanation tonometry, indirect ophthalmoscopy, lens phaco emulsification, surgical method, therapeutic method, slit lamp biomicroscopy, oxidative stress, meeting abstract.
Bock, P., A. Beineke, S. Techangamsuwan, W. Baumgartner, and K. Wewetzer (2007). Differential expression of HNK-1 and p75(NTR) in adult canine Schwann cells and olfactory ensheathing cells in situ but not in vitro. Journal of Comparative Neurology 505(5): 572-85.
NAL Call Number: QP351.J68
Abstract: Olfactory ensheathing cells (OECs) are promising candidates for autologous cell transplantation therapies of nervous system injury and disease. Large animal models are relevant for transferring experimental data into clinical practice. In vivo studies have suggested that adult canine OECs may display similar regenerating capacities as their rodent counterpart. However, data on their molecular phenotype required for generating pure cell preparations are still scarce. In the present study, we comparatively analyzed expression of the carbohydrate HNK-1 epitope and the neurotrophin receptor p75(NTR) in adult canine Schwann cells and olfactory ensheathing cells in situ and in vitro. Myelinating and nonmyelinating Schwann cells in situ exclusively expressed HNK-1 and p75(NTR), respectively, whereas OECs were negative for both markers. In vitro, OECs and Schwann cells shared cell surface expression of p75(NTR) but not of HNK-1, which could be detected transiently in intracellular vesicles. This suggests that Schwann cells and OECs in vitro phagozytose HNK-1+ cellular debris. The cultivation-induced downregulation of HNK-1 expression in Schwann cells and upregulation of p75(NTR) in OECs argues for the possibility that axonal signals control the expression of both markers in situ. Whereas HNK-1 expression in Schwann cells is most likely controlled by signals inducing myelination, e.g., neuregulin, the mechanisms that may suppress p75(NTR) expression in OECs in situ remain to be elucidated. Interestingly, HNK-1 expression in the adult dog was found in both sensory and motor nerve myelinating Schwann cells. This is reminiscent of humans and differs from rodents; it also underscores the importance of large animal models for translational research. (c) 2007 Wiley-Liss, Inc.
Descriptors: antigens, cd57 metabolism, biological markers metabolism, dogs, olfactory pathways metabolism, receptor, nerve growth factor metabolism, schwann cells metabolism, age factors, cells, cultured, fluorescent antibody technique, maxillary nerve cytology, models, animal, olfactory bulb cytology, olfactory mucosa cytology, olfactory pathways cytology, schwann cells cytology, sciatic nerve cytology, species specificity, stellate ganglion cytology, sympathetic nervous system cytology, trigeminal nerve cytology.
Bonatti, J.A., S.J. Bechara, M.W. Dall'Col, F.B. Cresta, P.C. Carricondo, and N. Kara Jose (2007). A fibrin-related line of research and theoretical possibilities for the use of fibrin glue as a temporary basal membrane in non-perforated corneal ulcers and in photorefractive keratectomy (PRK)-operated corneas. Arquivos Brasileiros De Oftalmologia 70(5): 884-9. ISSN: 0004-2749.
Abstract: PURPOSE: To report a specific line of research developed at the University of Sao Paulo/Brazil on fibrin glue used for sealing corneal perforations and the perspectives of use on non-perforated corneal ulcers and photorefractive keratectomy-operated corneas. METHODS: To describe fibrin glue manufacture, development of a device to test the glued perforated corneal area resistance, subsequent experimental investigations of the use of the fibrin glue in corneal perforations, reporting its efficacy, mechanical resistance experiments and histological study. Finally, the medical literature basis is searched to propose studies on the use of fibrin as a temporary basal membrane on non-perforated corneal surfaces like non-infectious corneal ulcers and on post-photorefractive keratectomy corneal surfaces. RESULTS: The development of fibrin glue, the device for resistance experiments, the efficacy, resistance and histological studies on fibrin glue used for sealing corneal perforations are reported as well as the scientific literature basis for the proposed studies on the use of fibrin as a temporary basal membrane on non-perforated corneas like non-perforated corneal ulcers and photorefractive keratectomy corneal surfaces. CONCLUSION: A specific line of research was reported on fibrin glue to seal corneal perforations at the University of Sao Paulo/Brazil and the theoretical perspectives for the use of fibrin in non-perforated corneal ulcers and on photorefractive keratectomy-operated corneas in an attempt to reduce corneal haze.
Descriptors: corneal diseases drug therapy, corneal ulcer drug therapy, fibrin tissue adhesive therapeutic use, membranes, artificial, research design, tissue adhesives therapeutic use, cornea injuries, corneal diseases surgery, dogs, intraocular pressure drug effects, lasers, excimer, models, animal, photorefractive keratectomy.
Colitz, C., A. Whittington, and J. Warren (2002). Measurement of p16 in canine lens epithelial cells in response to oxidative stress. Annual Meeting of the Association For Research in Vision and Ophthalmology, Fort Lauderdale, Florida, USA; May 05-10, 2002,
Abstract: Purpose: We previously demonstrated that lens epithelial cells (LEC) have telomerase activity. Neoplastic cells can have a reciprocal relationship between telomerase activity and levels of p16. Telomere length, development of senescence and p16 expression are influenced by oxidative stress. Since oxidative stress is implicated in cataractogenesis, the purpose of these experiments was to determine how exposure of LEC to tertiary butyl-hydroperoxide (TBHP) induced oxidative stress affects telomerase activity and p16 expression. Methods: Fresh canine lenses were incubated in keratinocyte growth medium and M199 with serum. In the first experiment, lenses were exposed to media with or without 0.5mM TBHP for varying time periods (8 lenses per group; 15, 25, 40, 60, 150 minute and overnight) In the second experiment, lenses were exposed to media containing 0.5 mM TBHP for one hour and then recovered in media without TBHP for varying time periods (8 lenses per group; 5, 60, 180 minute and overnight recoveries, no recovery, control group without treatment). Following these treatments, the anterior lens capsules with adhered LEC were collected. P16 levels in LEC were measured by ELISA using a dig- labeled antibody to p16. Telomerase activity was measured by TRAP-ELISA. Results: There was no change in p16 levels following direct exposure to TBHP. Telomerase activity was significantly up-regulated at the 150 minute point (p<0.01). The second group had significantly lower p16 levels (0.179-0.280) than the control group (0.441, p<0.05) at 15, 25, 40, 60, 180 minute and overnight recovery. Telomerase activity was significantly elevated at the 15, 60 and 180 minute and overnight recovery times (2.173-2.268) vs control (1.547, p<0.02). Conclusion: p16 is a cell cycle inhibitor that is down-regulated when telomerase activity is up-regulated in many tumors contributing to unregulated growth. Acute exposures with TBHP did not alter p16 or telomerase activity (except at 150 minutes) which may indicate that either the length of exposure may too short to cause changes in the proteins or the proteins' half-lives may be too long for changes to be seen in this experiment. In the recovery experiment, telomerase activity was up-regulated and p16 was down-regulated, similar to tumor cells. The recovery process following oxidative stress in LEC may involve proliferation of cells to replace damaged or dead cells. Future experiments will further examine the proliferative capacity of LEC under similar conditions and the response of p16 when LEC are chronically exposed to oxidative stress.
Descriptors: biochemistry and molecular biophysics, sense organs, sensory reception, tumor biology, tumor, neoplastic disease, elisa, immunologic techniques, laboratory techniques, trap elisa, oxidative stress.
Coppens, A.G., I. Salmon, C.W. Heizmann, R. Kiss, and L. Poncelet (2003). Postnatal maturation of the dog stria vascularis: an immunohistochemical study. Anatomical Record 270A(1): 82-92. ISSN: 0003-276X.
NAL Call Number: QL801 .A53
Abstract: The lateral wall of the dog cochlear duct was investigated by classical staining and immunohistochemistry for NaK/ATPase beta2 isoform, cytokeratins (Cks), vimentin, nestin, and S100A6 during the postnatal cochlear maturation, i.e., from birth to postnatal day 110. The dog stria vascularis was immature at birth. Fine melanin granules were evident in the stria from the second week of life, and melanin concentration increased drastically beyond the first month. The marginal cells were NaK/ATPase- and Ck-positive; intermediate cells were either nestin- and S100A6-positive or vimentin-positive; the basal cells were vimentin-positive; the capillary endothelium showed vimentin and nestin labeling; the cell layer underlying the stria was nestin-positive. The fibrocytes of the spiral ligament and spiral prominence expressed nestin and vimentin. The epithelial cells overlaying the spiral prominence and the external sulcus were Ck-positive, and transiently nestin- and vimentin-positive. Double immunolabeling, for S100A6 and either nestin, vimentin, or NaK/ATPase, and for nestin and vimentin suggested the presence of two distinct intermediate cell types. The results enabled us to differentiate the cell types forming the lateral wall of the dog cochlear duct, and to follow their postnatal maturation. This study may form a basis for future investigations about spontaneous cochleosaccular degeneration in dogs. This species is an important companion animal, and a possible model for the study of comparable diseases in humans.
Descriptors: biochemistry and molecular biophysics, development, sense organs, sensory reception, spontaneous cochleosaccular degeneration, ear disease, pathology, double immunolabeling, immunologic techniques, laboratory techniques, immunohistochemistry.
Ford, M.M., R. Bragadottir, E. Rakoczy, and K. Narfstrom (2003). Long - term visual behavior correlates with functional electroretinographic assessment after gene transfer in rpe65 - / - dogs. Annual Meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, FL, USA; May 04-08, 2003,
Abstract: Purpose: To assess the long-term effects of subretinal rAAV.RPE65 gene transfer on functional vision in RPE65-/- dogs. Methods: Five dogs homozygous for the RPE65 null mutation and 2 unaffected, visually normal control dogs were included. Affected animals had been treated subretinally with 70 - 100 mul of rAAV.RPE65 gene construct (2 X 1012 particles/ml) in the right eye (OD), and 0 - 100 mul of rAAV.GFP (2 X 1010 transforming units/ml) in the left eye (OS). Treatment for control dogs was 75 - 100 mul of the latter OD and 100 mul of BSS OS. Evaluations from pre-surgical and follow-up bilateral full-field electroretinograms (ERGs) 6 mo post-surgery were obtained. Objective assessment of functional vision was performed 3 and 6 mo post-operatively by counting the number of collisions made by the dogs as they negotiated a maze of obstacles in dim and day light conditions. Vision in individual eyes was also assessed 6 mo post-surgery. Results: Three mo after gene therapy there was a higher number of collisions in dim light than in day light (p<0.008) among affected dogs; a difference not evident 6 mo post-operatively. In day light conditions, no difference was noted between control and affected animals at 3 or 6 mo. In dim light, affected dogs had a higher number of collisions than control dogs at 3 (p<0.004) but not 6 mo post-operatively. Fewer collisions (p<0.1) were noted in day and dim light when only OD was exposed compared with exposure of only OS in the affected dogs. Post-surgery, high intensity scotopic stimuli and 30 Hz flicker ERG amplitudes were elevated (p<0.04) over pre-operative recordings in OD, and elevated over post-operative recordings in OS as well (p<0.032). Further, post-operative single flash photopic b-wave amplitudes for OS were increased over pre-operative values (p<0.05). Conclusions: Progressive improvement in functional binocular and monocular (OD) vision up to 6 mo after gene transfer was found by objective behavioral testing. The long-term visual improvement correlated with a significant increase in post-operative ERG amplitudes, mainly in OD but also with measurable effects in OS.
Descriptors: methods and techniques, molecular genetics, biochemistry and molecular biophysics, sense organs, sensory reception, functional electroretinography, laboratory techniques, gene transfer, genetic techniques, visual behavior.
Glover, T.L., M.P. Naisse, and M.G. Davidson (1995). Effects of topically applied mitomycin-C on intraocular pressure, facility of outflow, and fibrosis after glaucoma filtration surgery in clinically normal dogs. American Journal of Veterinary Research 56(7): 936-940. ISSN: 0002-9645.
NAL Call Number: 41.8 Am3A
Abstract: The effects of mitomycin-C on intraocular pressure (IOP), facility of outflow (C), and Tenon's capsule fibrosis were studied over 60 days in 10 clinically normal dogs. A 1-piece, silicone glaucoma implant was surgically implanted into both eyes; the filtration site of one eye was treated with a single, 5-minute intraoperative application of mitomycin (0.5 mg/ml), and the fellow eye was treated in a similar manner with balanced salt solution. There were no significant differences in preoperative IOP or C-values between treatment groups. Mean IOP in eyes of both groups initially decreased from the preoperative value, but returned to the baseline value by day 21. Mean facility of aqueous outflow (C-value) increased in all eyes during the first 14 days (mitomycin-C-value = 2.26 +/- 0.72; control C-value = 2.38 +/- 0.81), then reached a plateau that was significantly higher than the baseline value in mitomycin (P = 0.039) and control (P = 0.041) eyes. Histologic evaluation revealed all implants surrounded by a connective tissue capsule composed of regular dense collagen and fibroblasts that was significantly (P = 0.003) thinner in the mitomycin-treated (scleral side = 167 +/- 62 micrometer; conjunctival side = 122 +/- 41 micrometer) than the control (scleral side = 261 +/- 92 micrometer; conjunctival side = 180 +/- 48 micrometer) group. There were, however, no significant differences in IOP or C-values between groups at any postoperative time interval. Results of this study indicate that intraoperative treatment with mitomycin suppresses, but does not prevent fibrosis around silicone filtering implants.
Descriptors: glaucoma, surgery, mitomycin, topical application, internal pressure, fibroblasts, body fluids, flow, drug effects, aqueous humor outflow.
Notes: Includes references.
Hunter, L.S., D.J. Sidjanin, G.M. Acland, M. Villagrasa, and G.D. Aguirre (2003). Evaluation of pax6 for mutations causing inherited ocular diseases in canine models. Annual Meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, FL, USA; May 04-08, 2003,
Abstract: Purpose: Normal ocular development is dependent on the transcription factor PAX6. Mutations in PAX6 can result in aniridia, cataract, glaucoma, foveal hypoplasia and optic nerve hypoplasia in man. In mice, mutations in Pax6 cause the Small Eyepheonotype characterized by microphthalmia, abnormal lens and iris development and cataract. The purpose of this study is to evaluate the canine PAX6 gene for mutations causal to inherited ocular disease in canine models. Methods: Nine breeds of dog were identified having inherited forms of ocular disease for which PAX6 is a candidate gene. Two affected dogs from each breed were evaluated and their PAX6 sequence compared to canine wildtype sequence. Genomic DNA was prepared from whole blood and exons were scanned using intronic primers. Since the sequence for intron 4 could not be amplified, exon 4 was sequenced using primers in intron 3 and at the 3' end of exon 4, and exon 5 was sequenced using primers at the 5' end of exon 5 and in intron 5. Similarly, because of a homopolymer in the 3'UTR, exon 13 was evaluated using primers in intron 12 and at the 3' end of exon 13. Results: Thirteen exons plus an alternatively spliced exon (5a) are being examined in nine dog breeds with inherited eye diseases including cataracts, microphthalmia, persistent pupillary membranes, rod-cone dysplasia 2, cone-rod dystrophy 1 and 2, and aniridia. To date, no mutations associated with disease have been identified in the exons so far examined including the non-coding exons 1, 2, and 3. In addition to a previously identified SNP in intron 8, a single nucleotide change was identified in exon 7. This was a Cytosine -> Thymine change which did not result in an amino acid change. Microsatellites have been identified in exons 1 and 2, and in introns 6 and 7 which may facilitate linkage analysis. Conclusions: PAX6 plays an integral role in ocular development and mutations in this transcription factor cause different disease phenotypes. Evaluating canine models may identify novel disease phenotypes associated with PAX6 mutations.
Descriptors: molecular genetics, biochemistry and molecular biophysics, sense organs, sensory reception, aniridia, congenital disease, eye disease, genetics, cataract, cone rod dystrophy 1, cone rod dystrophy 2, inherited ocular disease, genetic disease, genetics, microphthalmia, persistent pupillary membrane, linkage analysis, genetic techniques, laboratory techniques, disease phenotype, ocular development.
Kador, P.F., K. Blessing, and M. Wyman (2003). The results of combretastatin in galactose - fed dogs with diabetes - like proliferative retinopathy. Annual Meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, FL, USA; May 04-08, 2003,
Abstract: Purpose: Combretastatin A-4 (CA4P) is a vascular targeting agent that has been reported to be capable of destroying newly formed capillary endothelial cells in growing vessels. The net effect of this drug has been to rapidly shut off blood flow in newly growing vessels and, as a result, regress neovascularization. The purpose of this study was to determine whether retinal neovascularization which results in altered retinal vessel blood flow and retinal permeability in the long-term galactose-fed dog can be halted with CA4P. Methods: All experiments conform to the ARVO Resolution on the Use of Animals in Research and NIH ACUC Guidelines. Eight beagles fed 30% galactose diet for 80-104 months and four age-matched control dogs were surgically made aphakic. Following recovery the dogs were divided into two groups each containing 4 galactose-fed dogs and 2 age-matched controls dogs with each group receiving CA4P either as sub-Tenon's injections administered at the corneoscleral junction or intravitreal injections. Six weeks after initial CA4P treatment all dogs also received systemic (IV) injections of CA4P. The extent of neovascularization and affect of CA4P administration were monitored by fluorescein angiography and color and monochromatic fundus photography at 2-week intervals. Results: Although CA4P was well tolerated by the healthy eyes of the control animals its administration to galactose-fed dogs was associated with corneal edema and increases in IOP after sub-Tenon's and intraocular injections. All galactose-fed dogs demonstrated retinal neovascular lesions and these were not ameliorated by either sub-Tenon's, intravitreal or systemic CA4P administration. Conclusions: Neovascularization in this animal model progresses over a period of years similar to that observed clinically. The failure of CA4P to ameliorate neovascularization suggests that chronic, long-term administration is required to destroy the slowly growing retinal endothelial cells.
Descriptors: cardiovascular system, transport and circulation, metabolism, pharmacology, sense organs, sensory reception, aphakia, eye disease, diabetes like proliferative retinopathy, endocrine disease, pancreas, metabolic disease, retinal blood vessel blood flow, retinal neovascularization.
Komaromy, A.M., J.J. Alexander, A.E. Cooper, V.A. Chiodo, L.G. Glushakova, G.M. Acland, W.W. Hauswirth, and G.D. Aguirre (2008). Targeting gene expression to cones with human cone opsin promoters in recombinant AAV. Gene Therapy 15(14): 1049-55.
Abstract: Specific cone-directed therapy is of high priority in the treatment of human hereditary retinal diseases. However, not much information exists about the specific targeting of photoreceptor subclasses. Three versions of the human red cone opsin promoter (PR0.5, 3LCR-PR0.5 and PR2.1), and the human blue cone opsin promoter HB569, were evaluated for their specificity and robustness in targeting green fluorescent protein (GFP) gene expression to subclasses of cones in the canine retina when used in recombinant adeno-associated viral vectors of serotype 5. The vectors were administered by subretinal injection. The promoter PR2.1 led to most effective and specific expression of GFP in the long- and medium-wavelength-absorbing cones (L/M cones) of normal and diseased retinas. The PR0.5 promoter was not effective. Adding three copies of the 35-bp LCR in front of PR0.5 lead to weak GFP expression in L/M cones. The HB569 promoter was not specific, and GFP was expressed in a few L/M cones, some rods and the retinal pigment epithelium. These results suggest that L/M cones, the predominant class of cone photoreceptors in the retinas of dogs and most mammalian species can be successfully targeted using the human red cone opsin promoter.
Descriptors: gene therapy methods, promoter regions, genetic, retinal cone photoreceptor cells metabolism, rod opsins genetics, targeted gene repair, color vision defects metabolism, color vision defects therapy, dependovirus genetics, dogs, gene expression, genetic vectors administration and dosage, green fluorescent proteins genetics, injections, models, animal, transduction, genetic methods, transgenes.
Notes: Comments: Erratum In: Gene Ther. 2008 Jul;15(14):1073^^Glushakova, L G [added].
Old, S.E., D.A. Carper, and T.C. Hohman (1995). Na,k-atpase response to osmotic stress in primary dog lens epithelial cells. Investigative Ophthalmology and Visual Science 36(1): 88-94. ISSN: 0146-0404.
Abstract: Purpose: Na,K-ATPase activity increases in lens cells exposed to hypertonic stress. To test whether the increase in activity involves stimulation of Na,K-ATPase expression, dog lens epithelial cells were subjected to hypertonic stress, and the time course of Na,K-ATPase protein and mRNA response was measured. Methods: Primary cultures of dog lens epithelial cells were maintained in isotonic or hypertonic media over the course of several days. Rubidium-86 uptake measurements, immunoreactive protein, and northern blot analysis were performed. Results: Dog lens epithelial cells exposed to hypertonic stress from culture medium supplemented with 150 mM NaCl or 250 mM cellobiose showed a twofold increase in Na,K-ATPase activity. The increase in activity was blocked by cycloheximide and was reversible when the cells were returned to isotonic medium. This activity was unaffected by the aldose reductase inhibitor, tolrestat. Na,K-ATPase protein and mRNA levels increased in cells exposed to medium containing 150 mM NaCl. Northern blot analysis showed that the alpha-1 and beta-1 mRNA levels increased as early as 6 hours and maximally increased 1.5-fold to twofold by 12 to 24 hours. Conclusions: Elevation of Na,K-ATPase activity in dog lens epithelial cells exposed to hypertonic stress was associated with increased expression of Na,K-ATPase subunit mRNAs and was dependent on protein synthesis. These results suggest that upregulation of the enzyme activity is the result of an induction of Na,K-ATPase.
Descriptors: biochemistry and molecular biophysics, cell biology, enzymology, biochemistry and molecular biophysics, metabolism, sense organs, sensory reception, enzyme activity up regulation, hypertonic stress, protein synthesis, sodium potassium atpase.
Panzan, C.Q., D. Guven, J.D. Weiland, R.R. Lakhanpal, M. Javaheri, E.J. de Juan, and M.S. Humayun (2004). Retinal thickness in normal and RCD1 dogs using optical coherence tomography. Ophthalmic Surgery, Lasers and Imaging 35(6): 485-93. ISSN: 1542-8877.
Abstract: BACKGROUND AND OBJECTIVE: To compare retinal thickness and retinal nerve fiber layer (RNFL) thickness values obtained by optical coherence tomography (OCT) in normal dogs and dogs with rod-cone dysplasia type 1 (RCD1). MATERIALS AND METHODS: Eight eyes of 6 normal hound-bred dogs and 12 eyes of 6 dogs with RCD1, 2 to 5 years of age, were examined using the Fast RNFL Thickness, Fast Macular Thickness, and line scan protocols of OCT. RESULTS: Retinal thickness was significantly higher in the tapetal fundus than in the non-tapetal fundus, in both normal (P = .0036) and RCD1 (P < .0001) dogs. Superotemporal, superonasal, and inferior retinal thickness values were significantly higher in normal dogs (P < .0001). Area centralis thickness was 183.5 +/- 10.66 microm in normal dogs and 136.16 +/- 13.12 microm in RCD1 dogs (P < .0001). There was no difference in RNFL thickness between normal and RCD1 dogs (P > .05). CONCLUSION: OCT scanning in dogs is considered to be a useful method of evaluation in future retinal studies in this animal model.
Descriptors: hound -bred dogs, rod-cone dysplasia type 1 (RCD1), optical coherence tomography (OCT), retinal thickness, tapetal fundus, retinal nerve fiber layer.
Pearce Kelling, S.E., A. Nickle, P. Didia, J. Jordan, G. Antonini, G. Aguirre, and G. Acland (2003). Retinal disease phenotype of the rdsf briard - derived rpe65 - / - dog. Annual Meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, FL, USA; May 04-08, 2003,
Abstract: Purpose. A naturally occurring canine RPE65-/- mutation, the cause of canine Lebers congenital amaurosis in the briard dog, provides a large animal model for the human disease. A laboratory strain of dogs has been derived from an affected male briard bred to colony dogs at the Retinal Disease Study Facility (RDSF), and used for asssesment of potential therapies. To establish baseline data, we have characterized the morphologic disease of the RDSF-derived strain of dogs. Methods. Age matched RPE65-/- and wt dogs were enucleated at different ages and their eyes were either fixed in paraformaldehyde, embedded in OCT, and then frozen-sectioned for immunocytochemical examination, or fixed in glutaraldehyde/formaldehyde, epon embedded and sectioned for morphological evaluation. Results. Examination of epon sections showed that by 16 weeks the rod outer segments (ROS) are slightly irregular in the RPE65-/- mutant. By 11 months the inferior retina showed very early retinal degeneration, characterized by shortening of ROS, but there was no apparent loss of outer nuclear layer nuclei. In contrast, disease in the superior retina was limited to ROS irregularities similar to that observed at 4 months. No morphological abnormalities were apparent in OCT embedded frozen sections except for lipid inclusions. These were present in the RPE of all diseased animals and were larger and more numerous in older animals. RPE65 protein was absent in the mutant dogs; all other retinal antigens examined (e.g. cone opsin, rhodopsin and insoluble IPM cone sheath) were expressed similarly between the mutant and wild type eyes. Conclusions. The RPE65-/- mutant shows abnormalities limited to the ROS at a young age; these progress slowly to a mild degeneration that is first observed in the inferior retina in the older animal. The preservation of photoreceptors during the first year of life gives a broad time window to examine the efficacy of therapies in this class of retinal diseases.
Descriptors: molecular genetics, biochemistry and molecular biophysics, sense organs, sensory reception, Lebers congenital amaurosis, congenital disease, eye disease, genetic disease, retinal degeneration, retinal disease, optimal computed tomography, clinical techniques, diagnostic techniques, imaging and microscopy techniques, laboratory techniques, immunocytochemical examination, immunologic techniques, retinal disease study facility, disease phenotype.
Rasmussen, C.A., B.T. Gabelt, and P.L. Kaufman (2002). Effect of win 55,212-2 on monkey and dog ciliary muscle in vitro. Annual Meeting of the Association For Research in Vision and Ophthalmology, Fort Lauderdale, Florida, USA; May 05-10, 2002,
Abstract: Purpose: To investigate the effect of WIN 55,212-2, a cannabinoid that has been reported to lower intraocular pressure (IOP) in primates, and its diluents on monkey and dog isolated ciliary muscle (CM) Methods: CM strips were mounted in a perfusion apparatus and contractile force measured in both the longitudinal (LONG) and circular (CIRC) vectors. CM was perfused with Krebs solution at a rate of 8 or 10 ml/min. Effects of WIN (10muM-40muM) were measured on carbachol (CARB; 1muM) precontracted CM and on CM at resting tension. Effects of different flow rates, DMSO and 2-hydroxypropyl-beta-cylodextrin (HPbCD) concentrations on the CM response were also measured. Results: Monkey CM response (mean+-s.e.m.) to CARB was 190+-72.1 mg LONG and 112+-37.8 mg CIRC (n=6). DMSO decreased the CARB response dose dependently by up to 57+-31.8% LONG and 45+-11.9% CIRC with 4% DMSO (n=6). The addition of 10 - 40muM WIN to CARB/4% DMSO resulted in minimal changes of up to -9+-13% LONG and -9+-19% CIRC (n=3) respectively, relative to the CARB/4%DMSO response. CM resting tension in Krebs/4% DMSO was 49.2+-25.0 mg LONG and 71.7+-16.1mg CIRC (n=3). The addition of 10 - 40muMWIN/4% DMSO resulted in changes of up to -30+-22% LONG, and -8+-4% CIRC respectively. None of the WIN responses seemed to be dose related. DMSO or HPbCD alone reduced resting tension by 32+-32% LONG and 6+-3% CIRC (n=10). CM response to CARB/2.25 or 4.5% HPbetaCD was increased by 7% LONG and 12% CIRC compared to CARB alone. WIN responses with HPbetaCD were similar to those obtained with DMSO. Dog CM contraction to CARB was much stronger than monkey (269+-129.3mg LONG and 178+-60.5mg CIRC, n=6). Otherwise the responses to WIN were similar. The optimal fluid flow rates through the chamber were 8 -10ml/min based on responses to CARB. Conclusion: WIN has minimal but variable effects on resting CM tension and CARB stimulated CM contraction. DMSO, and to a lesser extent, HPbetaCD can alter CARB contraction and resting tension; therefore care must be exercised in interpreting the responses to compounds which must be dissolved in these vehicles. Dog CM contracts strongly to CARB but its use as an alternative to monkey CM must be further evaluated with other compounds.
Descriptors: biochemistry and molecular biophysics, muscular system, movement and support, sense organs, sensory reception, intraocular pressure.
Tameesh, M.K., R.R. Lakhanpal, G.Y. Fujii, M. Javaheri, T.H. Shelley, S. D'anna, A.C. Barnes, E. Margalit, M. Farah, E.J. De Juan, and M.S. Humayun (2004). Retinal vein cannulation with prolonged infusion of tissue plasminogen activator (t-pa) for the treatment of experimental retinal vein occlusion in dogs. American Journal of Ophthalmology 138(5): 829-839. ISSN: 0002-9394.
Descriptors: animal model, enucleated porcine eyes, in vivo canine eyes, experimental branch retinal vein occlusion, local thrombolytic agents, safety testing.,retinal vein cannulation, surgical technique, microcatheter injection, tissue plasminogen activator (t-PA).