摘要:

Pre-retinal partial pressure of oxygen (PO2) profiles have been measured for the first time in the isolated arterially perfused eye of the cat. The perfusate, fed to the eye under a constant pressure head, contained no haemoglobin or haemoglobin analogue so that the only source of oxygen was in the dissolved form. Maximum oxygen supply is provided by raising perfusate PO2by equilibration with 100% O2. Periodic measurements of the DC corneal electroretinogram were used as a check on preparation viability. Using oxygen sensitive microelectrodes, oxygen tension profiles were measured in the vicinity of retinal vessels and also in vessel free areas, to determine the effect of the retinal circulation on the local oxygen environment of the vitreous. Results showed that large PO2gradients exist near retinal arteries whereas more than 1mm away from the retina the PO2gradient is very shallow. These results are in agreement with those obtained for the in vivo cat eye where the animal is breathed on 100% oxygen. Thus it can be concluded that the isolated perfused eye behaves similarly to the in vivo eye with respect to oxygen distribution and function.

ISSN:0271-3683    

DOI:10.3109/02713688609020050

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

An animal model of malignant melanoma of the eye was established by transplanting a cell suspension from cutaneous melanomas into the anterior chamber of the eye in Sinclair Farm miniature swine. The frequency of tumor takes in the eye was increased from 8.9% to 22% by treating the animals simultaneously with subconjunctival triamcinolone acetonide. As an animal model for hematoporphyrin derivative—photoradiation treatment of human malignant melanoma of the eye, this does not appear to be a good research tool because of the sporadic incidence of tumor takes, the rapid growth of tumor within the eye causing glaucoma, and the dark iris pigmentation of successful tumor takes, which hides extensive underlying ciliary body tumor.

ISSN:0271-3683    

DOI:10.3109/02713688609020051

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Previous morphological and biochemical studies indicate that a late appearing hereditary Emory mouse cataract may be a good model for certain human senile cataracts. The development of lenticular opacity in the Emory mouse is a slow process which provides an opportunity to conduct analysis of the progression of alterations that lead to cataract development. Biochemical investigatons have not yet demonstrated any specific correlation between alterations in the lens and the extent of opacity. We have conducted studies to determine the role of Na+K+-ATPase in the development of cataract in the Emory mouse. In this report we present results obtained on the site and level of activity of Na+K+-ATPase in six-and twelve-month-old Emory mouse lenses in which visible cataractous changes are beginning to appear. CFW mice (the parent strain) were used for controls in this study. Ultrastructural cytochemistry for the localization of Na+-K+-ATPase exhibited the enzyme reaction product for this enzyme to be present mainly between the lateral epithelial cell membranes and between the apical epithelial cell membranes and superficial cortical fiber membranes. In cortical fibers the reaction product was localized between fiber membranes. Although there was very little or no significant differences in the extent of reaction product in epithelial cells, the reaction product in the cortical fibers of six-month-old Emory mouse was less extensively distributed as compared to lenses from control CFW mice of the same age. The quantitative analysis showed a higher level of Na+K+-ATPase activity during the early stages (six months) of Emory mouse cataract development (precataract stage) which was reduced at twelve months of age. However, the Na+K+-ATPase activity in the Emory mouse lens appeared to be less than in CFW controls at both ages. The implications of these findings on the process of cataractogenesis in Emory mouse are presented in this report.

ISSN:0271-3683    

DOI:10.3109/02713688609020052

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Human stromal (fibroblast) cultures were established from random, normal corneas obtained from the International Eye Bank in Baltimore. Cultures were assessed for the expression of Class I, Class II, monocyte/granulocyte and T-cell antigens before and after treatment with gamma or alpha interferon (IFN), interleukin 2, and 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA). Class I (B2microglobulin) and monocyte/granulocyte (Leu M-1) antigens were evident before induction, natural killer cell (Leu 7) antigens were transiently expressed, and Class II (HLA-DR, Leu 10) antigens were not expressed until after induction with gamma IFN. PMA reduced the numbers of cells positive for Leu M-1 while alpha IFN and interleukin 2 had no effect on antigen expression. Kinetic studies of HLA-DR induction indicated that as little as 12 hours exposure to gamma IFN was sufficient to initiate induction and that 30% of the population was still expressing HLA-DR 7 days after removal of gamma IFN. The inducible expression of Class II antigens following lymphokine exposure may play a critical role in rejection of allografted corneas.

ISSN:0271-3683    

DOI:10.3109/02713688609020053

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

By light and electron microscope radioautographyin vivo, competitive binding sites for125I-Arg 101-Tyr 126 atrial natriuretic factor were localized mostly on the“pigmented”epithelium of the rat ciliary process. Further investigation using isolated ciliary processes from rabbits demonstrated the presence of specific receptors for125I-atrial natriuretic factor. In addition, synthetic atrial natriuretic factor inhibited basal and stimulated adenylate cyclase activity.These results demonstrate for the first time the presence of specific receptors for atrial natriuretic factor in the ciliary processes which are negatively coupled to adenylate cyclase. The possible role of this peptide in the control of intraocular pressure is suggested.

ISSN:0271-3683    

DOI:10.3109/02713688609020054

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Posterior vitreous detachment (PVD) and epiretinal membranes occur in a number of vitreoretinal diseases. We have developed an experimental model in which we can provide the morphologic correlation of these dynamic processes. The method provides the opportunity to study epiretinal membrane formation with the scanning electron microscope (SEM); with SEM, some epiretinal membranes that could not be readily detected either clinically or by routine light microscopy can now be Identified and studied in detail. We performed an experimental posterior penetrating injury with Injection of autologous whole blood or blood and lens material into the vitreous. Five eyes with posterior vitreous detachment but no retinal detachment were selected for SEM. A reduction in the cortical vitreous filaments and the presence of epiretinal membranes was apparent with SEM. In most areas the epiretinal membranes were separated from the Internal limiting membrane by a narrow cleft; however, limited attachment sites between the epiretinal membranes and retina were observed in areas overlying retinal blood vessels. In two eyes we observed microscopic retinal folds beneath the membranes, demonstrating a possible morphologic correlation between epiretinal cellular contraction and traction on the retina.

ISSN:0271-3683    

DOI:10.3109/02713688609020055

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

The effect of topically administrated indomethacin was studied in rabbits on an experimentally provoked inflammatory keratitis. Intrastromal injection with horse serum induced in the cornea a ring-shaped infiltration with leukocytes and neovascularization-Indomethacin was given as eye drops three times daily during the experiment. In the indomethacin treated eyes leukocyte infiltration was prolonged but not the concomitant neovascularization. The potentiation of the leukocyte response may be due to a facilitation of chemotactic lipoxygenase products.

ISSN:0271-3683    

DOI:10.3109/02713688609020056

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Corneal epithelium antibodies were detected in patients with corneal melting disease and uveitis using an immunofluorescence technique with cryostat sections of corneas obtained from various species (man, guinea pig, rabbit, mouse, rat, cow, pig). No differences in results were found using these various substrates, indicating that the autoimmune response is directed against common non-species specific corneal epithelium antigens.The serum of a patient with corneal melting disease, containing a high antibody titer a-gainst corneal epithelium was used to identify and isolate one of the bovine corneal antigens. A 54,000 dalton protein was isolated, which was shown to be the major protein present in the corneal epithelium. Absorption studies with other tissues taken from human eyes showed that cornea epithelium, cornea devoid of epithelium, ciliary body and retina contained material which cross-reacted with the isolated bovine corneal epithelium antigen, whereas iris and sclera showed no detectable cross-reaction.The incidence of autoantibodies directed a-gainst this antigen was investigated in patients with corneal melting disease, corneal transplantion and in uveitis patients using an ELISA and comparing the results with those obtained with the imunofluorescence assay on rabbit cornea sections. A positive ELISA was always associated with a positive immunofluorescence test. The presence of antibodies against the 54 Kd antigen as detected by the ELISA could be confirmed by immunoblotting in 7 out of 9 positive sera tested. A large number of sera showed a positive immunofluorescence test but a negative ELISA against the 54 Kd corneal epithelium antigen. The latter finding suggests that certain patients have antibodies against other, as yet not well defined, corneal epithelium antigens.

ISSN:0271-3683    

DOI:10.3109/02713688609020057

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Rabbit corneas were mounted in water jacketed chambers and the endothelial surface perfused with either BSS (Balanced Salt Solution) or BSS-Plus for 3 hr. Unidirectional and net fluxes of sodium were similar in both groups of corneas. Bicarbonate fluxes in BSS-Plus were statistically similar to those in Krebs-Ringer solution. Bicarbonate fluxes could not be determined with BSS because the solution does not contain bicarbonate. In addition, there was no statistically significant alteration of inulin or dextran permeability when comparing perfusion with BSS and BSS-Plus. From this study it appears that BSS and BSS-Plus are comparable in their ability to maintain corneal endothelial physiologic function duringin-vitroperfusion. This is in contrast to previous work which showed that BSS-Plus induced less endothelial morphologic change than BSS. It is concluded that morphologic alterations may be more sensitive parameters of endothelial stress than are fluxes and permeabilities.

ISSN:0271-3683    

DOI:10.3109/02713688609020058

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0271-3683    

DOI:10.3109/02713688609020059

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor