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Biomedical subjects

U Pleyer

Publications and source records attributed to U Pleyer.

At least 19 recordsLinked to original sources
PubMed1992

Use of collagen shields containing amphotericin B in the treatment of experimental Candida albicans-induced keratomycosis in rabbits.

We evaluated the effect of collagen shields presoaked with amphotericin B on the treatment of experimental Candida albicans-induced keratitis. Treatment results were compared to those of amphotericin B eyedrops instilled hourly. Forty-eight albino rabbits received intrastromal injections of 10(8) C. albicans organisms. Twenty-four hours later, eyes were treated for eight hours each day with hourly instillation of 0.15% amphotericin B drops, hourly instillation of saline drops, or application of a collagen shield presoaked in 0.5% amphotericin B for one hour. The rabbits were killed after one, three, or five days of treatment. Quantitation of fungi in the cornea was achieved by culturing homogenates and counting colony-forming units. Treatment with amphotericin B applied either as hourly instilled drops or absorbed in collagen shields significantly (P less than .05) reduced corneal fungal counts at all time points when compared to saline-treated control eyes. Rabbit eyes treated with amphotericin B-soaked collagen shields had significantly lower fungal counts compared with hourly instilled amphotericin B drops at Days 1 (P = .02) and 3 (P = .04), but not at Day 5. The collagen shields were as effective in reducing the number of colony-forming units as were amphotericin B drops at Day 5. These data suggest that collagen shields soaked in amphotericin B could be a useful and convenient treatment device in keratomycosis such as that caused by C. albicans.

Administration, Topical↗
PubMed1992

[Clinical aspects, follow-up and results of cataract extraction in uveitis].

Over a 5-year period, a consecutive series of 52 eyes in 46 patients with uveitis underwent extracapsular cataract extraction. Twenty-eight of these cases received a posterior chamber intraocular lens (IOL). During an average follow-up of 25 months (range 7 to 58 months) 71% of eyes receiving an IOL achieved postoperatively a visual acuity of 0.5 or better; 54% of aphakic eyes reached this level. Persistent cystoid macular edema limited the visual improvement to 20/200 in 6 patients; none of the patients developed cystoid macular edema postoperatively on clinical observation. Intraocular hypertension occurred postoperatively in 12 eyes, but was limited to a 4-week postoperative period in 9 cases. YAG laser capsulotomy was performed in 2 eyes with opacification of the posterior lens capsule without any further complications. The results suggest that uveitis patients benefit from cataract extraction and in selected cases can tolerate IOL implantation without major complications.

Adolescent↗
PubMed1992

The effect of systemic decomplementation with cobra venom factor on corneal complement levels in guinea pigs.

The authors examined the effect of systemic administration of cobra venom factor (CVF) on hemolytic complement levels in guinea pig sera and corneas. Guinea pigs received repeated intraperitoneal injections of CVF. Sera and corneas were obtained before and 1, 2, 5, 8, 10, 12, 16, and 20 d after the initial injection of CVF. Total hemolytic complement activity was measured by lysis of sheep erythrocytes sensitized with rabbit antibodies. There was a significant decrease in serum complement levels at days 1, 2, 5, 8, and 10 after the initial injection of CVF. After this, complement levels rose to levels that exceeded preinjection values. Complement levels in corneas also declined after CVF injections with a significant decrease at days 2, 5, 8, and 10 and a return to normal thereafter. Corneal complement depletion and restoration lagged behind serum. Moreover, the rate of complement depletion and restoration was greater for serum than cornea. Light microscopic examination of representative corneas at each time did not show local tissue changes during decomplementation. This is first study (to the authors' knowledge) to document corneal complement depletion by systemic administration of CVF. Low-to-absent corneal complement levels were present 2 d after the initial injection of CVF and persisted for 6 d. This model could be used to study the influence of complement on traumatic and immunologic injuries to the cornea.

Animals↗
PubMed1992

Immune response to Staphylococcus epidermidis-induced endophthalmitis in a rabbit model.

Although Staphylococcus epidermidis is the most common cause of postoperative pseudophakic endophthalmitis, little is known about the immune response to S. epidermidis-induced endophthalmitis. Using a rabbit model, the immune response to an intravitreal injection of 7000 S. epidermidis (group 1) or 30,000 S. epidermidis (group 2) organisms was investigated. Clinical evaluations showed that rabbits in group 2 had a more severe inflammatory reaction in the conjunctiva, cornea, iris, and vitreous than those in group 1. The inflammatory reaction in group 1 largely resolved by day 30; group 2 continued to show a severe inflammatory response. Histopathologic findings correlated with clinical findings, with rabbits in group 2 showing a more severe inflammatory reaction in both the anterior and posterior segments of the globe. Positive vitreous cultures for S. epidermidis were present in rabbits in group 1 on days 3, 7, 10, 14, and 21 but not thereafter. However, group 2 had higher vitreous colony counts at days 3, 7, and 14 and negative vitreous cultures thereafter. Neither group showed delayed hypersensitivity to S. epidermidis antigens (evaluated by skin tests). Serum immunoglobulin (Ig) G antibody levels to phenol-inactivated S. epidermidis and glycerol teichoic acid (GTA) increased progressively, reached a peak at days 10-14, and then declined in both groups. Serum IgA antibody levels to these antigens were not detected. Group 2 had a more prolonged IgG antibody response in vitreous and aqueous than group 1. Tear fluid showed the weakest IgG and IgA antibody response to S. epidermidis and GTA. S. epidermidis-induced endophthalmitis was associated with a humoral but not a delayed hypersensitivity response to this organism.

Animals↗
PubMed1991

Elevated prolactin levels in human aqueous humor of patients with anterior uveitis.

Evidence is accumulating that prolactin (PRL) may play a physiological role in the regulation of humoral and cell-mediated immune responses. On the basis of these observations, we measured levels in the serum and aqueous humor of 28 patients with cataract or anterior uveitis with concomitant cataract. Intraocular concentrations were measured in a range from 0.1 to 3.4 ng/ml. Whereas serum PRL levels failed to show significant differences between the two groups (P = 0.39), intraocular concentrations were significantly higher in uveitis patients (P less than 0.001). The level in aqueous humor did not reflect the serum concentration in either group. To the best of our knowledge, this is the first study measuring PRL concentrations in human aqueous humor.

Adolescent↗
PubMed1991

Device drug delivery to the eye. Collagen shields, iontophoresis, and pumps.

External devices have been used to enhance drug delivery. This article reviews the role of collagen shields, iontophoresis, and pumps used to deliver ophthalmic medications. Collagen shields have been used to deliver drugs and promote corneal epithelial healing. Presoaked collagen shields deliver many drugs to the eye as well as or better than traditional methods such as frequent topical therapy or subconjunctival injection. The efficacy of drug delivery by collagen shields was demonstrated in animal models of graft rejection and bacterial keratitis. Iontophoresis uses an electrical current to carry an ionized drug across tissue. Transcorneal iontophoresis delivers high concentrations of a drug to the anterior segment of the eye. Transscleral iontophoresis bypasses the lens-iris diaphragm and produces adequate vitreous levels. Pumps deliver fluid to the eye for extended periods of time via a tube with its distal opening in the conjunctival sac, corneal stroma, anterior chamber, or vitreous cavity. Clinical acceptance of the collagen shield for drug delivery to the anterior segment is better than iontophoresis or pumps, probably because the collagen shield is simpler and more convenient to use.

Absorption↗
PubMed1991

[Intraocular availability of liposome encapsulated monoclonal antibodies in the rabbit model. Results of a pilot study].

The results of local application of monoclonal antibodies (mAb) in rabbit eyes are presented. To improve intraocular access of the high-molecular-weight protein it was entrapped in large (0.2 microns) unilamellar, negatively charged liposomes. Concentrations of the free or encapsulated drug were measured by ELISA in different eye compartments following repetitive drop administration or single subconjunctival injection. Although mAb became measurable in specimens of conjunctiva and cornea, it was not detectable (less than 0.5 ng/ml) in aqueous humor, lens or the vitreous body. In contrast, concentrations of the liposome-encapsulated drug were measurable as little as 30 min after topical application in the aqueous humor.

Animals↗
PubMed1991

[Bromocriptine in therapy of chronic recurrent anterior uveitis].

In animal studies, bromocriptine (Pravidel) has demonstrated immunosuppression because of inhibition of prolactin. After publication of positive results in the treatment of uveitis in a few case reports and in an uncontrolled study we conducted a double-blind placebo-controlled study in 13 patients with chronic recurrent anterior uveitis who had experienced three or more recurrences during the previous year. Therapy was started gradually during the symptom-free interval and continued for 1 year with 2.5 mg twice daily. Two recurrences or relevant side effects led to discontinuation of the therapy. In the bromocriptine group, 2 of 7 patients had no recurrences during the study period. Two patients had to stop because of two recurrences but, in contrast to earlier recurrences, they responded to local corticosteriod treatment within a few days. The remaining 3 patients (1 with one recurrence, 2 without) had to stop because of the side effects (arterial hypotension, arthritic complaints). In 5 of 6 patients in the placebo group treatment was stopped because of recurrences and in 1 patients because she believed she was experiencing a side effect from bromocriptine (breast atrophy). In summary, bromocriptine seems to have a prophylactic effect on anterior uveitis. Side effects were frequent but mild compared to other immunosuppressives. In case of arterial hypotension, additional therapy could make this drug more tolerable.

Adolescent↗
PubMed1990

[Drug-induced exudative erythema multiforme major with a chronic progressive course and bilateral blindness. Clinical and immunohistologic follow-up].

A 24-year-old male patient who had been received Fansidar developed exudative erythema multiforme major with massive involvement of the skin, mucous membranes, and both eyes. The chronic inflammation led to proliferation of the conjunctiva, with keratinization of the ocular surface and corneal vascularization. The final result was comparable to cicatricial pemphigoid, with blindness of both eyes. In histological sections, massive lympho-plasma-cellular infiltration with circumscribed perivasculitis was seen. The lymphocyte transformation test was still positive 18 months after onset of the disease. Class II antigens were evident in some of the conjunctival biopsies.

Adult↗
PubMed1990

[Isolated infiltration of the vitreous body as a sign of blast crisis in chronic myeloid leukemia].

A 29-year-old man with chronic myeloid leukemia and two successfully treated blast crises exhibited ocular symptoms. Eighteen months after the diagnosis of leukemia he presented with unilateral hyperplastic iris stroma, anterior chamber inflammation and vitreous infiltration. Uveitis was diagnosed tentatively, and local therapy was begun with corticosteroids. Because the findings remained unchanged an invasive diagnostic evaluation followed. Although iris biopsy revealed only unspecific mononuclear cell infiltration (mainly T-lymphocytes), selectively aspirated vitreous material contained myeloid cells of different stages of maturation and blast cells. Peripheral blood, liquor and bone marrow showed no signs of acceleration or transition of the primary disease. Thus, an extramedullary blast crises with isolated vitreous infiltration was diagnosed.

Adult↗
PubMed1990

[Clinical types of immunologic transplant reactions following perforating keratoplasty].

The incidence of allograft rejection was determined for 740 penetrating keratoplasties performed between 1980 and 1987. All 740 cases were followed up for at least 1 year. The reaction forms of allograft rejection were grouped according to biomicroscopic appearance. The incidence and progression of symptoms are described. Rejection types are subdivided into patients with favorable versus poor prognosis. Of the patients 37.9% demonstrated an immune response (including discrete forms). Clear reaction patterns within the two groups of patients became apparent when reaction variations were carefully differentiated. Epithelial immune reaction was found in 5.2%/10.5% and subepithelial infiltration in 1.7%/4.8% of the patients with favorable/poor prognosis. The largest disparity in frequency occurred in progressive endothelial reaction; 3.8% in patients with favorable versus 36.7% in patients with poor prognosis. Focal endothelial reactions occurred in both groups with comparable frequencies (14.1%/13.3%). The large percentage of immunological reactions, including late manifestations (approximately 12% after 1 year) and some with irreversible progression, warrants continuing efforts to treat and prevent this complication.

Cornea↗
PubMed1989

Topical treatment of severe corneal ulcers with cyclosporin A.

Cyclosporin A eye drops were used on six patients to treat corneal ulcers associated with rheumatic diseases, oculomucocutaneous syndrome, and Sjögren's syndrome. Conjunctival excision was additionally carried out in two cases. All ulcers healed rapidly. The mechanism of ulcer formation involving T-lymphocytes is discussed.

Administration, Topical↗
PubMed1989

[Bromocriptine: a new therapy concept in the treatment of chronic recurrent uveitis?].

Chronic recurrent uveitis still responds unsatisfactorily to therapy. Prolactin, a pituitary hormone that attains high blood levels physiologically in stress situations, has an immune modulating effect. The prolactin antagonist bromocriptine (2 x 2.5 mg/day) was administered prophylactically to prevent recurrence in seven patients with chronic iritis/iridocyclitis or panuveitis (Group A). On this therapy two patients suffered a mild recurrence (in one case in the first month). Another patient developed rebound uveitis after discontinuing bromocriptine medication. Tolerance appears to vary considerably, and in three patients the therapy had to be discontinued because of arterial hypotension and congestive rhinopathy, respectively. The three patients in Group B (with iritis, sympathetic ophthalmia, and intermediate uveitis) received bromocriptine in addition to cyclosporin A after plasmapheresis. This combination resulted in an elevated cyclosporin A plasma level, and the dosage was reduced by 30-50% (plasma level 70-120 ng/ml). With this lower dosage of cyclosporin A, the creatinine level of one of the patients returned to normal. Viewed on the basis of these initial results bromocriptine would appear to reduce the number of recurrences of chronic uveitis. Moreover, the synergism with cyclosporin A, described both theoretically and in an animal model in the literature, appears attainable in therapy.

Adult↗
PubMed1989

[Nonspecific eye autoantibodies in uveitis].

Under certain pathologic circumstances autoantigens lead to the formation of autoantibodies. In uveitis, autoimmunologic phenomena will also be discussed. We studied 149 sera of uveitis patients for various organ specific and non-organ specific autoantibodies. We found antisarcolemal autoantibodies (ASA) mainly in patients with acute iritis (59% positive) but also in panuveitis (40%) and iridocyclitis (29%). On the other hand antiendothelial antibodies (AEA) could be found in 43% of patients with chorioretinitis. Antisinusoidal antibodies (SA) have been detected in iritis and panuveitis patients more often than in the control group which show positive autoantibodies in 5% of all cases. Using ELISA we looked for antibodies against keratin, laminin and microsomes. Because antimicrosomal-, antilaminin- and antisarcolemal-antibodies recognize the same epitope, there was a good correlation of these three autoantibodies. Similar clusters of autoantibodies (ASA, AEA and SA) have been found in various infectious diseases and in chronic inflammatory diseases in which an infectious component is discussed. These results may indicate that iritis, iridocyclitis, chorioretinitis and panuveitis are secondary reactions of eye tissue following a systemic primary disease. Especially viruses are well-known for their production of autoantibodies. In patients with intermediate uveitis we could not demonstrate these autoantibodies more often than in the control group, favouring theories which believe in an autoimmune reaction against vitreous elements.

Antibodies, Antinuclear↗