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Retinal pigment epithelial (RPE) cells induced to express MHC class II (HLA-DR) by incubation with interferon gamma (IFN-gamma) were investigated for their ability to present a microbial superantigen to T lymphocytes. Superantigens bind to MHC class II antigens and appear to play a role in a number of infectious and autoimmune diseases through stimulation of large numbers of T cells. Primary cultures of human RPE cells treated with IFN-gamma for three days to induce HLA-DR expression bound staphylococcal enterotoxin E (SEE) via HLA-DR and presented SEE to T cells as measured by proliferation of purified peripheral blood T cells and IL-2 synthesis by the Jurkat T cell line. Untreated RPE cells were essentially ineffective as superantigen presenting cells. These results suggest that MHC class II expressing RPE cells could contribute to immune and inflammatory activity in the eye by presenting superantigens to T lymphocytes. [ABSTRACT FROM AUTHOR]

Purpose: To examine the relationship between optic nerve head (ONH) and finger blood flow in subjects with and without a primary vascular dysregulation (PVD)., Methods: ONH blood flow and finger blood flow was measured in 15 subjects with PVD and in 24 subjects without PVD. PVD was defined as being present if it was detected in patient history as well as by nailfold capillaromicroscopy. PVD was defined as being absent if the patient history for PVD was negative and the results of nailfold capillaromicroscopy were negative. Scanning laser Doppler flowmetry (LDF) was used to measure ONH and finger blood flow. Finger temperature was measured in all subjects using a contact sensor., Results: ONH blood flow is significantly related to finger blood flow in subjects with PVD (p<0.01), but not in subjects without a PVD. Subjects with PVD had a significantly lower finger skin temperature in comparison to those without PVD (p<0.01), Conclusions: The present study indicates a relationship between ONH and finger blood flow in subjects with PVD. This might be an indirect sign of a disturbed autoregulation of ocular blood flow in PVD subjects.

Background: The eye and the progressive lenses in eyeglasses form a three-dimensional optical system, which must be well matched., Patient: A 71-year-old man complained about a new and unusual tearing and scratching sensation in his eyes. The work-up revealed subnormal values of the Schirmer test, from the eye refraction of different eyeglass powers and strongly decentred progressive lenses in his, just a few-months-old, eyeglasses., Therapy and Outcome: A lubricating therapy remained without success. However, the use of new and correct eyeglasses eliminated the symptoms., Conclusion: Tearing and the sensation of scratching in the eyes in this case are symptoms of an eyeglasses-induced asthenopia. Consequently, it may pay to control the eyeglasses and the centration of progressive lenses in cases with unclear, unspecific eye symptoms even without dissatisfaction with eyeglasses.

Since proliferative vitreoretinopathy (PVR) is associated with an inflammatory reaction and interleukin-1 (IL-1) initiates a cascade of inflammatory mediators, we determined the intravitreal levels of IL-1 in experimental PVR. In the blood-trauma model of PVR in rabbits, we measured the intravitreal levels of IL-1 alpha and IL-1 beta using a radioimmunoassay and performed immunohistochemical staining of cells from the vitreous. We found that on day 1 polymorphonuclear and from day 2 on mononuclear inflammatory cells predominated in the vitreous. IL-1 alpha- and IL-1 beta-positive cells with a large cytoplasm were observed on days 4 and 8. However, the IL-1 alpha and IL-1 beta concentrations in the vitreous did not exceed the radioimmunoassay sensitivity limit 8 h, 1, 2, 4 and 8 days after trauma, while in 2 control rabbits injected with additional endotoxins we found 5.6 and 8 ng/ml IL-1 beta. We conclude that despite IL-1-positive cells, presumably macrophages, PVR is not associated with high levels of IL-1. No conclusions concerning the low levels of IL-1 alpha and IL-beta can be drawn due to the performance of the RIA.

The Human Genome Project will identify, map and sequence all 50,000-100,000 human genes and will provide the tools to determine the genetic basis of both common and rare diseases. Understanding the genetic basis of human disease will allow for the development of highly specific drugs and for replacement of the altered gene through gene therapy. Gene therapy may also be used to introduce a new function into cells with resulting therapeutic benefit. Genes may be delivered into cells in vitro or in vivo utilizing viral or nonviral vectors. Viral vectors which have been used include retroviruses, adenoviruses, adeno-associated viruses and herpes viruses. Ocular disorders with the greatest potential for benefit of gene therapy at the current time include hereditary ocular diseases, including retinitis pigmentosa, tumors such as retinoblastoma or melanoma, and acquired proliferative and neovascular retinal disorders. We have demonstrated the feasibility of ocular gene therapy in a rabbit model of proliferative vitreoretinopathy, using retroviral vectors containing the herpes simplex virus thymidine kinase 'suicide' gene. Although in vivo transduction efficiency is low, the strong bystander effect results in prominent killing of proliferating cells in this model leading to inhibition of disease. In the future, gene therapy has the potential for the replacement of defective gene products or introduction of new gene products into ocular cells. The selection of appropriate target genes and cells will be critical, as will the development of a methodology for safe, targeted gene transfer.

Background: The development of proliferative vitreoretinopathy (PVR) results often from a breakdown of the blood-retina barrier and the intraocular accumulation of serum proteins and leukocytes, particularly monocytes, that then come into contact with retinal pigment epithelial (RPE) cells. To examine the effect of these two factors on RPE proliferation, which is characteristic of PVR, we used a coculture system of blood monocytes and human RPE cells., Methods: RPE cells were incubated with a variable number of monocytes at different serum concentrations and assayed for proliferation by [3H]-thymidine incorporation and cell counting. To assess cell-cell communication. RPE cells were labeled with 2', 7' -bis(carboxyethyl)-5(and 6) carboxyfluorescein acetoxy-methyl ester, and the dye transfer to monocytes was analyzed using an UV microscope., Results: Monocytes (P < 0.0004) and serum (P < 0.0001), each on its own, significantly stimulated RPE cell growth, and these two variables were interrelated (P < 0.0001), showing a potentiating synergism. In serum-free medium, monocytes increased proliferation to just above control levels, whereas the same number of monocytes in 5% serum increased the [3H]-thymidine incorporation 3.8 times. This effect was greatly reduced by prevention of direct cell contact by means of placement of a well insert, which also lessened the monocyte-induced proliferation in both serum-free and serum-containing medium. Furthermore, the transfer of the intracellular dye from RPE cells to cocultured monocytes indicates that RPE cells transferred parts of their cytoplasm to monocytes., Conclusion: These observations underline the importance of protein leakage through a damaged blood-ocular barrier and of direct contact of monocytes/macrophages with RPE cells, as well as their reciprocal potentiating effect on RPE cell proliferation. Thus, early stabilization of the blood-ocular barrier, which would preclude or reduce protein leakage and invasion of inflammatory cells into the eye, could be a target for pharmacologic prevention of PVR.

Retinal pigment epithelial (RPE) cells produce and respond to a variety of cytokines; however, molecular and biochemical studies are restricted by the limited access to large numbers of pure cells and the variability associated with different donor sources. Despite success in establishing primary human RPE (HRPE) cell cultures, the inability to sustain consistent proliferation rates and morphology over several passages remains a concern. This problem was approached by using an immortalized line of simian virus (SV)40 transformed fetal HRPE cells (SVRPE). Cytokine production, receptor expression and responsiveness in the SVRPE cell line was analyzed to determine the usefulness of this model for studying HRPE-cytokine interactions. Using reverse transcriptase polymerase chain reaction (RT-PCR), HRPE and SVRPE cells demonstrated an identical pattern of interleukin-1 receptor (IL-1R), IL-2R (alpha sub-unit), IL-6R, interferon (IFN)-gamma R and tumor necrosis factor-alpha (TNF)R p55 expression. No amplification products for TNFR p75 or granulocyte/macrophage colony stimulating factor (GM-CSF)R were demonstrated in either population. IFN-gamma stimulation induced surface human leukocyte antigen (HLA)-DR in both SVRPE and HRPE, while TNF treatment induced surface expression of intercellular adhesion molecule (ICAM)-1 on SVRPE and upregulated ICAM from basal levels on HRPE. Both cell types showed amplification products for interleukin (IL)-1 beta, IL-6 and transforming growth factor (TGF)-beta 1 using RT-PCR. The bioassays demonstrated that both populations of unstimulated cells constitutively secrete very low levels of TGF-beta and no IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Intraocular transplantation of genetically modified cells that release a particular substance could have a major impact on the treatment of various ocular diseases. We studied the expression of the reporter gene beta-galactosidase (lacZ) in transplanted retinal pigment epithelial (RPE) cells in vivo., Methods: RPE cells from pigmented rabbits were transduced with the beta-galactosidase gene in a retroviral vector. Cells were then assayed for gene expression and transplanted subretinally into the eyes of New Zealand White rabbits. RPE cells that were transduced with a similar vector without the beta-galactosidase gene were used as controls. Rabbits were killed on days 1, 7, and 21 and the eyes processed for transmission electron microscopy, Results: Neomycin-resistant rabbit RPE cells that showed beta-galactosidase activity were generated within 2-5 weeks. After transplantation, viable RPE cells that expressed the transgene and that phagocytosed rod outer segments were observed on days 1, 7, and 21, Conclusions: The results show that generation of genetically modified RPE cells is feasible and that the transplanted cells remain viable and continue to express the transgene in the subretinal space of the host animal for at least 21 days. Transplantation of such genetically modified RPE cells could provide a new tool for studying retinal diseases and, potentially, for correcting metabolic abnormalities in retinal degenerations and dystrophies.

Purpose: Retinal pigment epithelial (RPE) cells express human leukocyte antigen (HLA)-DR (class II) antigens when stimulated with interferon gamma (IFN-gamma) and may be capable of local antigen presentation. The authors examined the effect of transforming growth factor-beta (TGF-beta), a cytokine normally found in the eye, on the expression of these immunoregulatory molecules in vitro and attempted to determine the mechanism by which this cytokine acts., Methods: Human RPE cells were cultured in the presence of IFN-gamma and then stained immunohistochemically for HLA-DR antigens. TGF-beta 1 or TGF-beta 2 was added simultaneously with IFN-gamma or after 3 days of IFN-gamma treatment. In parallel experiments, RPE cells were pretreated with 4-phorbol-12 myristate-13 acetate (PMA), staurosporine, or calphostin C before stimulation with IFN-gamma or TGF-beta. Quantitative analysis was performed by fluorescence-activated cell sorting., Results: IFN-gamma induced HLA-DR expression on RPE cells. Both TGF-beta 1 and TGF-beta 2 were able to inhibit this effect. These inhibitory effects of TGF-beta were augmented by pretreatment with either PMA or calphostin C. Pretreatment of the cells with PMA before stimulation with IFN-gamma downregulated HLA-DR expression. Staurosporine pretreatment suppressed HLA-DR expression by IFN-gamma-stimulated RPE cells, but this was not additive with TGF-beta., Conclusions: The authors conclude that TGF-beta 1 and TGF-beta 2 strongly inhibit the IFN-gamma-induced upregulation of class II antigens on human RPE cells. The modulation of these IFN-gamma and TGF-beta effects by calphostin C, staurosporine, and PMA treatment suggests involvement of the protein kinase C pathway.

Background: Transforming growth factor-beta (TGF-beta) plays an important role in the pathogenesis of many ocular diseases, including proliferative vitreoretinopathy. We examined the effect of TGF-beta on the phagocytosis of rod outer segments by retinal pigment epithelium (RPE), which is a major function of RPE, and investigated the dependence of this effect on the protein kinase C (PKC) pathway., Methods: Phagocytotic uptake of fluoresceinated bovine rod outer segments was determined by flow cytometry. RPE cells were treated with TGF-beta 1 or TGF-beta 2 and their effects on phagocytosis were examined. The effects of various PKC inhibitors (calphostin C, staurosporine, and extended exposure to phorbol 12-myristate 13-acetate, PMA) and a stimulator (brief exposure to PMA) on RPE phagocytosis was evaluated., Results: Both TGF-beta 1 and TGF-beta 2 up-regulated RPE phagocytosis and PMA abolished the up-regulating effect of TGF-beta. In contrast, PKC inhibition by staurosporine and calphostin C resulted in increased phagocytosis. A combination of TGF-beta and PKC inhibitor treatment did not produced any additive effect on phagocytosis., Conclusion: We concluded that TGF-beta up-regulates human RPE phagocytosis, but that this effect is counteracted by PKC activation. It is possible that this TGF-beta-induced effect is due, in part, to a negative modulation of the PKC-dependent pathway.

Because fibronectin (FN) is known to be present in membranes in proliferative vitreoretinopathy, we sought to identify cytokines that regulate the release of FN by retinal pigment epithelial cells (RPE). Levels of FN in the supernatant of cultured human RPE cells were quantified with an ELISA, after which the cells were stimulated with human recombinant cytokines, interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), interferon gamma (IFN-gamma), transforming growth factor beta 1 and 2 (TGF-beta), and phorbol myristate acetate (PMA). Protein kinase C (PKC) was blocked by 2 nM calphostin C or 1 mM staurosporine. RPE cells released FN into the supernatant constitutively. TGF-beta 1 and TGF-beta 2 upregulated the FN release in a dose- and time-dependent manner. The other cytokines tested were without effect. In combination, IFN-gamma and IL-1 beta reduced the effect of TGF-beta. PMA, which is a PKC activator, also increased the release of FN in a dose-dependent manner. Blocking of PKC with specific inhibitors abolished the effects of TGF-beta and PMA. The results show that TGF-beta is a potent stimulator of FN release by RPE cells, and exerts its effects via signal transduction involving PKC. Its effect is reduced by IFN-gamma.

To determine whether immunoglobulins of the IgG class diffus up to the corneal center after subconjunctival injection, rabbits were injected with fluorescein-isothiocyanate-labeled human IgG. The inoculum diffused from the entire periphery centrepetally towards the corneal center. The progression of the diffusion front slowed down as the distance to the limbus increased. The first increase of fluorescence in the corneal center was observed on day 6. The intensity increased during the following 10 days despite resorption in the corneal periphery due to the flow of IgG from paracentral toward central areas. The diffusion coefficient of 0.003-0.004 cm2/day was calculated by computer simulation using Fickian diffusion equations adapted for corneal geometry. We conclude that after subconjunctival application, IgG diffuses up to the corneal center with a delay of several days and that the penetration speed decreases as the distance to the limbus increases. This kinetics contributes to our understanding of the role of IgG in corneal pathology and may help to design therapeutic schedules for immunotherapy with IgG.

A new immunoglobulin preparation for topical administration in the eye has been developed. The tolerance to this preparation was tested in a phase I/II study, in combination with the antiviral drug trifluorothymidine, in 5 patients with untreated episodes of herpes simplex epithelial keratitis. The clinical course of these patients was within usual limits, with a mean healing time of 6.6 days (range 2-15 days). No undesirable effects were observed. Our findings suggest that this new treatment modality is safe and offers a new perspective, but additional studies are required to determine its efficacy.

Two patient histories show that the therapy of contact lens corneal ulcers is complicated by bacterial resistance and mixed infection. To start an effective therapy against pseudomonas, gram-negative as well as gram-positive germs, a primary combination of tobramycin with fusidic acid seems to us as reasonable. Because of possible resistance to these antibiotics a smear should be taken from the ulcer and the contact lens case before therapy is begun and the clinical evolution must be controlled. In the choice of the antibiotics, the actual state of resistance and commercial availability was taken into account.

The pars plana approach to cataract extraction in the pediatric age has several advantages. We report of 9 eyes with congenital cataract and discuss the advantages of the pars plana technic. In all cases a single surgical approach was sufficient. There were no complications postoperatively which made either surgical or medical treatment necessary. Postoperatively aphakia was corrected with contact lenses. During pars plana-lensectomie the central part of the anterior and posterior capsule is removed and an anterior vitrectomie is performed. With this procedure secondary cataract formation could always be prevented.

An important complication of paracentesis with disposable needles is injury to the lens being caused by the intraocular part of the needle. The new needle has a locking mechanism which prevents its penetrating too deeply into the eye and thus reduces the danger of lens injury. The tip of the needle has been extended in the shape of a lance to reduce the pressure during the puncture of the cornea and to avoid the Seidel phenomenon. The needle can be combined with a tuberculin syringe or pipette. It is superior to disposable needles, particularly in situations in which unexpected movements must be taken into account, i.e. during paracentesis in children, paracentesis where assistants are involved or during cumbersome manipulations.

We report a case of Laurence-Moon-Bardet-Biedl Syndrome with all five recognised features: tapetoretinal dystrophy, polydactily, obesity, mental retardation and hypogonadism. Nevertheless the correct diagnosis was delayed due to the fact, that the patient has a macular dystrophy (instead of a pigmentary retinopathy). He had an operation of the polydactily during childhood. This was not revealed at first. The case underlines the importance of an exact anamnesis of the parents.

Yersiniosis is a food-born infection. It may cause an acute enterocolitis and trigger an anterior uveitis. We report a case of bilateral panuveitis with chorioretinitis - thus with the involvement of anterior and posterior uvea. Because the agglutination titer against the Yersinia enterocolitica type 3 was increased, we consider it as the most probable etiology of the panuveitis. A serological test for Yersinia should be done in patients with uveitis, who consume food from various sources e.g. tourists or with diarrhea in anamnesis.

We report a case of severe, bilateral panuveitis with disseminated chorioretinis. With systemic steroid therapy the inflammation resolved within 4 weeks, resulting in chorioretinal scarring. Because the agglutination titer against Yersinia enterocolitica type 3 was increased to 6 times over normal, we consider Yersinia to be the most probable cause of the panuveitis. Concomitantly, serology revealed evidence for recent infection with mumps and shigella. Both can cause anterior uveitis. Therefore, we cannot exclude interactions, which may influence the clinical picture. After reviewing the literature we describe for the first time a case of chorioretinits and panuveitis associated with infection by Yersinia.

We report on a 33-year-old male Turkish patient with primarily nonsuspect sexual behavior who presented with panuveitis unresponsive to therapy. HIV infection and secondary syphilis was diagnosed. The uveitis was the only manifestation of syphilis. Because of isosporiasis, an HIV infection of CDC class IV C1 was diagnosed. This is the second published case of acquired syphilitic uveitis in a patient with HIV infection. The diagnosis was delayed by a prozone phenomenon. Treatment with high doses of penicillin i.v. for 14 days led to complete recovery. Because the HIV infection may obscure the diagnosis of syphilis, this constellation will assume increasing importance with the growing number of HIV-infected patients.