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Biomedical subjects

U Schönherr

Publications and source records attributed to U Schönherr.

At least 19 recordsLinked to original sources

[Microsurgical quality assurance exemplified by cataract surgery].

BACKGROUND: The new German laws demand comprehensive quality assurance in all hospitals. The prerequisite for this in ophthalmic microsurgery is the complete documentation of all relevant surgical details including patient comorbidity. METHODS: Since 1989 we have documented all microsurgical procedures using a computer-based surgery recording system. To analyze the changing spectrum of cataract surgery in a university eye hospital, we evaluated 12,653 consecutive cataract extractions divided into 5 periods between 1990 and 1999. RESULTS: Within these periods the patients' age changed significantly (p < 0.001), whereas the gender showed no significant change (p = 0.34). Furthermore, there was an increase in the number of simultaneous surgical procedures (p < 0.01) as well as the frequency of the pseudoexfoliation syndrome (p < 0.001). In addition the mean duration of cataract procedures decreased (p < 0.001) and the occurrence of vitreous loss also decreased (p < 0.001). CONCLUSIONS: Long-term documentation of all relevant patient data enables valid evaluation of the patient spectrum. Furthermore, this monitoring helps to manage the challenge of quality assurance in ophthalmology.

Aged↗

Differential activation of TRAIL-R1 and -2 by soluble and membrane TRAIL allows selective surface antigen-directed activation of TRAIL-R2 by a soluble TRAIL derivative.

TNF-related apoptosis-inducing ligand (TRAIL) is a typical member of the tumor necrosis factor (TNF) ligand family that is expressed as a type II membrane protein (memTRAIL) and signals apoptosis via the death domain-containing receptors TRAIL-R1 and -2. Soluble recombinant derivatives of TRAIL (sTRAIL) are considered as novel tumors therapeutics because of their selective apoptosis inducing activity in a variety of human tumors but not in normal cells. Using antagonistic antigen-binding fragment (Fab) preparations of TRAIL-R1- and TRAIL-R2-specific antibodies, we demonstrate in this study that TRAIL-R1 becomes activated by both the soluble and the membrane-bound form of the ligand, whereas TRAIL-R2 becomes only activated by memTRAIL or soluble TRAIL secondarily cross-linked by antibodies. Furthermore, we show that the restricted signal capacity of sTRAIL can be readily converted into a fully signal competent memTRAIL-like molecule, i.e. a TRAIL-R2 stimulating ligand, by genetic fusion to an antibody derivative that allows antigen-dependent 'immobilization' of the fusion protein to cell surfaces. We conclude that antibody targeting-dependent activation can be used to design selective therapeutics derived of those ligands of the TNF family that are biologically inactive in their soluble form.

Animals↗

[Quality management according to DIN EN ISO 9001 at a university eye hospital].

BACKGROUND: Quality assurance is an integral part of modern microsurgical ophthalmology. Health care laws also mandate overall quality management. MATERIALS AND METHODS: In recent years we have standardized the preexisting features of quality management according DIN EN ISO 9001 and have integrated previously missing features. RESULTS: Establishing quality management according to ISO 9001 is possible even at a university eye hospital and department of ophthalmology. Certification according to ISO 9001 specifications was granted in April 1999. The major difficulty was in translating industrial norms to the context of an eye hospital. It was also difficult to overcome skepticism towards quality-assurance measures that lie beyond ophthalmological quality control. CONCLUSION: It is useful and feasible to establish a quality management system at German university eye hospitals and departments of ophthalmology. Certification according to ISO 9001 is one possibility to make a quality management system transparent and evaluable both inside and outside the hospital.

Certification↗

[Adamantiadis-Behçet syndrome: fluorescein angiography and choroid ischemia].

BACKGROUND: Adamantiadis-Behçet's disease is a chronically progressing multisystemic disorder. The underlying disease mechanism is an obliterative vasculitis of unknown etiology. Main clinical symptoms are oral and genital aphthous ulcers and intraocular inflammations. Additionally, cutaneous, rheumatoid, neural, gastrointestinal, or cardiovascular manifestations may be observed. Diagnosis is based on clinical features since currently no specific laboratory tests or pathognomonic histopathological features are available. Ocular changes may provide important diagnostic clues to the systemic disease. PATIENTS AND METHODS: In a retrospective fashion 196 patients of the Department of Ophthalmology of the University of Erlangen-Nürnberg between 1988 and 1998 with retinal vasculitis seen by fluorescence angiography were evaluated according to the diagnostic criteria of the "Behçet's Disease Research Committee of Japan". RESULTS: Among 196 patients there were 12 patients with Adamantiadis-Behçet's disease. Apart from retinal vasculitis, angiographic features included capillary dropout in 64% (9/14), swelling of the optic disc in 79% (11/14) and irregularly delayed areolar filling of choriocapillaris in the early phase of fluorescence angiography in 43% (6/14) of eyes. There was no statistically significant relationship between severity of the systemic disorder and the activity of the ocular disease. CONCLUSION: Apart from retinal vasculitis, 43% of eyes in patients with Adamantiadis-Behçet's disease presented a delayed choroidal filling in fluorescence angiography as a sign of choroidal involvement of occlusive vasculitis. We observed leakage of fluorescein from the optic disc, which could be due to a secondary inflammation of the ciliary circulation. Inflammatory involvement predominantly of choroidal vessels, as visualized in fluorescence angiography, may be a diagnostic lead in Adamantiadis-Behçet's disease.

Adolescent↗

[Laser tyndallometry and monitoring of treatment in 20 children with juvenile uveitis].

BACKGROUND: Treatment of children with juvenile uveitis requires adequate control of inflammation while minimizing systemic or ocular side effects. The study was performed to evaluate the potential use of the laser flare-cell meter in monitoring and adjustment of therapy in juvenile uveitis. PATIENTS AND METHODS: Retrospectively, we monitored 20 children (11 girls and 9 boys) with an age range from 3 to 15 years presenting with juvenile iridocyclitis (10/20), intermediate (5/20) or posterior (5/20) uveitis. During the follow-up period (median 25.2 months, range: 2 to 83 months) multiple clinical controls were performed. We recorded clinical data, present therapy, and measurements using the laser flare-cell meter (Kowa FC-1000). RESULTS: Laser flare-cell meter measurements were easily obtained and highly reliable even in these young patients. During follow-up, 36 recurrences of intraocular inflammation were detected in 19 eyes. Relapses of inflammation as well as a response to treatment were seen at an early stage. Semiquantitative observations of cells and aqueous flare in the anterior chamber, or visual acuity of patients were less reliable in predicting recurrences. CONCLUSIONS: Laser tyndallometry offers a reliable, examiner-independent method to assess intraocular inflammation in children with juvenile uveitis and to adjust the necessary treatment.

Adolescent↗

Age-related macular degeneration and optic disk morphology.

PURPOSE: To assess the relationship between age-related macular degeneration and appearance of the optic disk. METHOD: By morphometric evaluation of wide-angle color fundus photographs, 143 patients with age-related macular degeneration were compared with 33 normal subjects and with 83 diabetic patients. RESULTS: Size and shape of the optic disk and size of parapapillary atrophy did not vary significantly (P > .12) between the study groups. CONCLUSIONS: Age-related macular degeneration is not associated with special features in the appearance of the optic disk. Parapapillary atrophy, large or small optic disk, and abnormal disk shape are neither risk factors nor protective factors of age-related macular degeneration.

Adult↗

Recurrent optic nerve head infarctions associated with combined factor V Leiden- and factor II:G20210A-mutation.

PURPOSE: To demonstrate the association of bilateral recurrent optic nerve head infarctions with thrombophilia due to combined factor V:R506Q- and factor II:G20210A-mutation. METHODS: Case report. We examined a 55-year-old man with a two-year history of three segmental optic nerve head infarctions. Visual acuity was 20/80 on the left and 20/25 on the right eye. RESULTS: Ophthalmologic, cardiologic, radiologic, neurologic and hematologic-immunologic examinations were unremarkable except for increased APC-resistance (APC ratio: 1.4; normal value >2) due to heterozygous factor V:R506Q-mutation and high factor II-levels due to factor II:G20210A-mutation. Therapy with coumarin was instituted at INR 2.0-3.0 and no relapse has occurred over the past 1-year period. CONCLUSION: Combined occurrence of thrombogenic factor II:G20210A-mutation and factor V:R506Q-mutation may be causally linked to recurrent optic nerve head infarctions.

Factor V↗

Peters anomaly.

Explore the source record for details and available documents.

Child↗

[Acute reversible night blindness caused by vitamin A deficiency in pancreatic carcinoma].

BACKGROUND: Vitamin A deficiency is a leading cause of blindness in childhood in the developing countries. In developed countries xerophthalmia occurs mainly as secondary hypovitaminosis due to malabsorption in chronic alcoholism or intestinal disorders. PATIENT AND METHODS: A 24-year-old female patient complained of night blindness since one week. There was a history of pancreas tail resection combined with radiation due to a papillary low grade cystic carcinoma at the age of 15. During a review period of 9 years of follow-up there was a slow disseminated metastatic spread including the liver. Despite a progressive tumor cachexia the patient was practising a profession. Visual acuity was 20/20 OU with normal visual fields. Dark adaptation was reduced to one log unit and scotopic electroretinography was extinguished. Serum vitamin A level was reduced to 75 ng/ml (normal range 400-700 ng/ml). RESULTS: Under vitamin A substitution dark adaption and scotopic electroretinography normalized and night blindness disappeared within 7 days. CONCLUSIONS: In malabsorption syndromes, especially in combination with liver manifestations, xerophthalmia should be considered as a potential complication. Vitamin A substitution should be administered if necessary. In cases of malignant tumors differential diagnosis includes the cancer associated retinopathy (CAR).

Adult↗

[Outcomes after penetrating keratoplasty in congenital hereditary corneal endothelial dystrophy (CHED). Report on 13 eyes].

BACKGROUND: Congenital hereditary endothelial dystrophy (CHED) is a rare bilateral corneal disease. The stromal opacity is supposed to result from terminal misdifferentiation of the endothelial cells. In this study we present the morphological and functional results after penetrating keratoplasty in children with CHED who were operated in our department between 1981 and 1997. PATIENTS AND METHODS: In a retrospective clinical cross-sectional study we looked up case histories of 13 eyes from 8 children (7 female, 1 male) with a mean age of 6.0 +/- 3.1 years (ranged from 3 to 14 years). In all children penetrating keratoplasty was performed by one surgeon (GOHN), in 3 eyes using nonmechanical excimer laser trephination. The graft-diameter was in 7 eyes 7.0/7.1 mm, in 2 eyes 7.0/7.2 mm, in 2 eyes 6.5/6.6 mm (resp. 6.8 mm), in 2 eyes 6.0/6.1 mm (resp. 6.2 mm). Fixation of grafts was achieved in 2 eyes by single running suture, in 8 eyes by double running suture and in 3 eyes by multiple interrupted sutures. RESULTS: During a mean follow-up of 4.0 +/- 2.4 years visual acuity increased in all patients (from light perception to 6/20 preoperatively to 2/200 to 14/20 postoperatively). In one patient corneal endothelial-epithelial-decompensation occured (both eyes unterwent previous antiglaucomatous surgery elsewhere), and in 1 patient loosening of one suture happened after 10 month. No immunological graft reaction occurred during follow-up. After excimer laser trephination (3 eyes from 2 patients) visual acuity and corneal astigmatism after surgery was favorable in comparison to all other patients. CONCLUSION: In children with CHED penetrating keratoplasty results not only in a clear cornea but also in a satisfactory functional outcome. Postoperatively periodical morphological controls and assessment of refraction as well as means to prevent amblyopia are indispensable before age 7.

Adolescent↗

Effects of antioxidants on motility and membrane integrity of chilled-stored stallion semen.

The use of chilled-stored stallion semen is limited by its relatively short-term fertilizing capacity. An important reason for the decrease in fertility during storage is the peroxidation of sperm membrane lipids. In this study, effects of the antioxidants ascorbic acid (0.45 and 0.9 g/L) and catalase (0.45 x 10(6) and 1.8 x 10(6) units/L) on chilled-stored stallion semen were investigated. Semen was collected by artificial vagina from 7 stallions and was diluted with skim milk extender or glycin extender. Sperm motility and membrane integrity were investigated after dilution and after 24, 48 and 72 h at 5 degrees C. Ascorbic acid significantly increased the percentage of membrane-intact spermatozoa at 24, 48 and 72 h at 5 degrees C when compared with that of the controls (P < 0.05), irrespective of the extender. Ascorbic acid decreased the percentage of progressively motile spermatozoa (P < 0.05) at a concentration of 0.9 g/L in glycin extender. Catalase decreased (P < 0.05) progressively motile spermatozoa after 24, 48 and 72 h at 5 degrees C in skim milk extender at a concentration of 1.8 x 10(6) units/L. Catalase decreased (P < 0.05) the percentage of membrane-intact spermatozoa at 24 h. Motility and membrane integrity of spermatozoa after dilution with glycin extender containing catalase did not differ from the controls. In conclusion, ascorbic acid has protective effects on sperm membrane integrity in diluted stallion semen.

Journal Article↗

[Angiogenesis and inhibition of angiogenesis in the eye].

BACKGROUND: Angiogenesis is the formation of new blood vessels from preexisting vessels. Angiogenesis plays an important physiologic and pathologic role in the eye. Pathologic angiogenesis can be found in major causes of human blindness as in diabetic retinopathy and age-related-maculopathy. In recent years great progress has been made in recognizing the mechanisms and regulation of angiogenesis. RESULTS: The general mechanism and the regulation of angiogenesis with proliferative diabetic retinopathy as an example of ocular angiogenesis are reviewed according to recent literature. Angiogenic and antiangiogenic factors regulate the neovascularization. Recent research has identified the vascular endothelial growth factor as the most important mediator of ocular angiogenesis. As well in diabetic retinopathy as in age-related-maculopathy the vascular endothelial growth factor plays a role. New knowledge about ocular angiogenesis is linked to the chance of new antiangiogenic therapies in neovascularizing eye diseases. There exist two ways of ocular antiangiogenic therapy: the first way is to block ocular angiogenic factors such as vascular endothelial growth factor, the other way is to influence the interaction between endothelial cells and extracellular matrix of the newly forming vessels. CONCLUSION: Recent progress in angiogenesis research could result in new causal antiangiogenic drug therapy in ophthalmology. There are some promising animal experiments of local and systemic antiangiogenic therapy. Because of its anatomic localisation the eye is especially suitable for topic antiangiogenic therapy.

Cell Hypoxia↗

[Pseudoexfoliation syndrome in patients with retinal vein branch and central vein thrombosis].

BACKGROUND: Pseudoexfoliation syndrome is a frequent cause of secondary open-angle glaucoma due to deposition and in situ-production of abnormal extracellular matrix proteins in the trabecular meshwork. Glaucomas itself are a known risk factor for retinal vein thrombosis. In this retrospective study the prevalence of pseudoexfoliation syndrome in patients with branch and central retinal vein thrombosis was investigated. PATIENTS AND METHODS: The records of 332 unselected patients with branch retinal vein thrombosis and 159 with central retinal vein thrombosis, which were seen in our laser out-patient clinic between January 1990 and July 1996, were analysed retrospectively. RESULTS: 6.0% of patients with branch and 6.9% of patients with central retinal vein thrombosis revealed pseudoexfoliation syndrome. The full picture of pseudoexfoliation syndrome was seen in 4.2% of patients with branch and in 4.4% of patients with central retinal vein thrombosis. The prevalence of pseudoexfoliation syndrome increased with age. Twenty percent of patients with branch and 27% of patients with pseudoexfoliation syndrome and branch or central retinal vein thrombosis. The branch retinal vein thrombosis was significantly more often localised at the disk in patients with glaucoma and in patients with pseudoexfoliation syndrome. CONCLUSIONS: Pseudoexfoliation syndrome is a risk factor for retinal vein thrombosis. Pathogenetically the secondary open-angle glaucoma caused by pseudoexfoliation syndrome could be causative for the venous thrombosis.

Adult↗

Ochrobactrum anthropi endophthalmitis after uncomplicated cataract surgery.

PURPOSE: To treat a case of Ochrobactrum anthropi endophthalmitis after uneventful cataract surgery. METHODS: A 66-year-old patient in good general health underwent uncomplicated cataract surgery in his right eye. Seven weeks later, pars plana vitrectomy with removal of the intraocular lens became necessary because of progressive low-grade endophthalmitis resistant to topical and systemic erythromycin, cephalosporins, aminoglycosides, and colistin. RESULTS: Microbiologic examination of the vitreous biopsy, capsule, and anterior chamber fluid disclosed O. anthropi, a nonfermentative gram-negative bacillus sensitive to imipenem, amikacin, ciprofloxacin, and vancomycin. CONCLUSION: Ochrobactrum anthropi and its natural resistance against many antibiotics should be considered in the treatment of low-grade endophthalmitis after uneventful cataract surgery.

Aged↗