Factor XII deficiency and central retinal vein occlusion.
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Biomedical subjects
Publications and source records attributed to W Philipp.
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The amendment of the German Veterinary Legislation concerning the eradication of notifiable diseases demanded also an updating of the relevant disinfection measures and technologies. Some hints are given, based on own experimental results, for the choice of chemical disinfectants, on some special problems of disinfection in livestock buildings and of disinfection of animal slurry and farm-yard manure as well as on biotechnological disinfection methods and environment-friendly disinfectants.
Seasonal affective disorder is a form of depression which recurs at the same time of the year. Exposure to bright artificial light at a dose of 2,500 lux is used to treat seasonal affective disorders. We exposed a pigmented (Brown Norway) and a nonpigmented (Sprague-Dawley) rat strain with bright artificial light for 21 days at two doses (2,500 and 6,100 lux) and analyzed dopamine, dihydroxyphenyl-acetic acid, 5-hydroxytryptamine (5-HT), and 5-hydroxyindole-acetic acid (5-HIAA) by high performance liquid chromatography (HPLC) and electrochemical detection in eight different brain regions. Furthermore, we measured tissue levels of substance P (SP), neurokinins (NK), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), and neuropeptide Y (NPY) with radioimmunoassay. Our data obtained with light microscopy show that bright artificial light at both doses induced a massive destruction of photoreceptors in the retina of albino rats but not of the pigmented rat strain. Retinal lesion of photoreceptors resulted in increased tissue levels of all measured neuropeptides except SP in the hypothalamus and increased VIP in the ventral tegmental area/substantia nigra. Furthermore, increased 5-HT and 5-HIAA tissue levels were found in the ventral tegmental area/substantia nigra. In contrast, in the frontal cortex there was a significant reduction in 5-HIAA tissue levels and a decreased 5-HIAA/5-HT ratio, indicating decreased 5-HT metabolism. Light exposure of the pigmented rat strain revealed no changes in the measured biogenic amines and neuropeptides in any investigated brain region. Our data suggest that retinal lesion but not direct visual neurotransmission induced changes in neurotransmitters in some brain regions. We conclude that Brown Norway rats but not Sprague-Dawley rats are useful to study neurochemical effects of bright artificial light. However, Sprague-Dawley rats may be a useful tool to study biochemical mechanisms of photoreceptor damage by bright light.
We report the nucleotide sequence and genome organization of the human papillomavirus type 42. HPV42 DNA was isolated from vulvar papillomas. It has been detected in benign forms of proliferative lesions only. The genome of HPV42 is 7917 bp long and shows the open reading frame pattern conserved in all HPVs sequenced so far. HPV42 has no high degree of sequence homology to any of the known HPVs. It shows characteristics previously found either exclusively in HPVs associated with invasive carcinomas or exclusively in nongenital HPVs. Therefore it cannot be readily ascribed to any of the established subgroups of human papillomaviruses.
A case of orbital involvement in Waldenström's macroglobulinemia is presented. Orbital echography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed and revealed a retrobulbar mass of the right orbit. Ultrasonography suggested a lymphoid orbital tumor. A CT scan was nonspecific, but helpful in exactly locating the tumor and excluding bony lesions. Signal intensity patterns of MRI were characterized by a low intensity on T1- and T2-weighted images. A marked enhancement of the tumor was evident after intravenous injection of a paramagnetic contrast agent (gadolinium-DTPA). Although the definite diagnosis could only be established by means of an ultrasound-guided fine-needle aspiration biopsy, MRI in connection with the history of our patient strongly suggested a diagnosis of orbital lymphoma in Waldenström's disease.
We investigated the glycoconjugates in frozen sections of keratoconus corneas, using a panel of 12 biotin- or fluorescein isothiocyanate-labeled lectins. No differences between the lectin binding sites of the epithelium, endothelium and Descemet's membrane of normal and keratoconus corneas could be observed. However, in contrast to normal corneas, intense staining with peanut agglutinin (PNA) could be detected at breaks in Bowman's layer, in scar tissue and in the adjacent stroma. Furthermore, in the majority of cases binding sites for Phaseolus vulgaris erythroagglutinin (PHA-E) and increased staining with Ricinus communis agglutinin I (RCA-I) and Lens culinaris agglutinin (LCA) could also be detected in ruptures in Bowman's layer and in scar tissue. These data suggest that the scarred regions of the anterior stroma in keratoconus corneas may contain oligosaccharides with terminal D-galactose (beta 1-3)-D-N-acetylgalactosamine disaccharides (recognized by PNA), increased amounts of glycoconjugates with terminal beta-galactose residues (recognized by RCA-I), increased amounts of glycoconjugates with glucose/mannose residues (recognized by LCA), and finally, biantennary complex-type glycopeptides containing two outer galactose residues and a residue of N-acetylglucosamine (recognized by PHA-E). Since corneal scars due to causes other than keratoconus revealed lectin binding sites (particularly for PNA and to a lesser extent also for PHA-E, LCA and RCA-I) similar to those seen in scar tissue of keratoconus corneas, we conclude that it is mainly scar formation that may be responsible for the altered lectin binding sites in keratoconus.
Langerhans cells (LC) in normal human corneas (with the exception of newborns) lack thymocyte antigen T6, a highly specific marker for noncorneal LC. Because corneal LC could not be induced to express T6 antigen when cultured with various cytokines including interleukin-1 (shown to modulate T6 expression on gingival LC), some authors assume that corneal LC may represent a distinct LC subpopulation that is innately inactive. In this study, 62 corneas from patients with various corneal diseases were investigated for the presence of T6 and histocompatibility antigen HLA-DR on LC in the central and pericentral epithelium. Both T6- and HLA-DR-positive LC at a high density similar to that observed in normal epidermis could be detected in the epithelium of five corneas with epidermalization after alkali burns. Furthermore T6- and HLA-DR-positive LC at smaller densities also were detected in corneas from patients with chronic herpetic stromal keratitis, zoster keratitis, chronic allograft rejection, and bacterial corneal ulcers. Although the functional significance of T6 expression on corneal LC remains to be determined, the induction of T6 antigen on corneal LC may represent an important event for the antigen-presenting function of these cells in various corneal diseases including corneal allograft rejection.
A specific high-performance liquid chromatographic (HPLC) method using precolumn derivatization and fluorescence detection was developed for the determination of the monoamine oxidase B inhibitor Ro 19-6327 in human plasma. After extraction of the basified plasma with tert.-butyl methyl ether-1-butanol (8:2, v/v) and back-extraction into dilute phosphoric acid, the solution was neutralized with phosphate buffer and the drug derivatized with fluorescamine. The derivative was chromatographed on a reversed-phase C8 column, using phosphate buffer-acetonitrile (68:32, v/v) as mobile phase, and fluorescence detection (excitation 370 nm, emission 485 nm). The limit of quantification was 1 ng/ml using 1 ml of plasma. The recovery was 79% in the range 5-200 ng/ml and the inter-assay precision was 3.1-7.9% in the range 2-500 ng/ml. The compound proved to be stable in human plasma. Moderate instability was found in rat plasma and, surprisingly, severe instability in dog plasma. Measures for handling unstable dog plasma samples are described. An HPLC method with UV detection was used for the analysis of dog and rat plasma samples, which is also described briefly. The fluorescence method, which was five times more sensitive than the UV method, was successfully applied to a human tolerance study.
Direct intravitreal injection of antibiotics plays an important role in the management of bacterial endophthalmitis. In the present study we investigated the toxicity and clearance of intravitreally injected cefotetan in a rabbit model. No toxic ocular side effects could be detected by electroretinography (ERG) or light and electron microscopy up to and including a single intravitreal dose of 1000 micrograms. Intravitreal injection of 2000 micrograms cefotetan resulted in mild degeneration of photoreceptor outer segments and, sporadically, in cataract formation. After intravitreal injection of 4000 micrograms, moderate toxic degeneration of photoreceptors occurred, with displacement and mitochondrial swelling of inner segments. In addition, lysosomal lamellar inclusion bodies could be detected in pigment epithelial cells. After a single intravitreal injection of 1000 micrograms cefotetan, concentrations greater than the minimum necessary for the inhibition of most commonly occurring intraocular pathogens (except Pseudomonas aeruginosa and Staphylococcus epidermidis) were maintained in the vitreous humor for greater than 48 h. Cefotetan may be a potentially important drug for intravitreal injection, especially in cases of gram-negative and suspected anaerobic endophthalmitis.
An aqueous-drainage silicone device was implanted in a 57-year-old diabetic patient with neovascular glaucoma after failure of conventional therapy. Postoperative intraocular pressure (IOP) was well controlled, ranging between 10 and 20 mm Hg without the use of supplemental agents. Despite the normal IOP, the eye became painful and amaurotic 11 months after implantation due to progression of the retinopathy accompanied by the development of severe tractional retinal detachment. Enucleation was performed and the eye underwent histopathological examination. The filtering bleb around the silicone plate of the implant on the equatorial sclera was lined with a thick layer of collagenous connective tissue. Numerous microcystic spaces could be seen in the bleb wall by light microscopy. Electron microscopy confirmed this finding; in addition, only a meshwork of collagen fibre-like bundles was visible at some areas of the innermost bleb wall. Control of IOP in spite of bleb fibrosis in this particular case may have been due to a loss of matrix components and to the formation of microcystic spaces in the bleb wall, which seem likely to be channels for the passage of aqueous humor.
Using immunohistochemical techniques, we investigated the distribution and frequency of Langerhans cells in corneal buttons obtained from patients who underwent corneal transplantation because of various corneal diseases. The frequency of these dendritic cells was similar to that in the normal epidermis in corneas with epidermalization after severe alkali burns. Numerous Langerhans cells, albeit in smaller numbers, were also present in the central corneal epithelium of patients with keratitis due to infection with herpes simplex virus, keratitis due to herpes zoster virus, bacterial corneal ulcers, corneal scars, corneal ulcers associated with rheumatoid arthritis, and patients with chronic corneal allograft reactions. The presence and persistence of Langerhans cells in diseased corneas may account for, at least in part, a breakdown of corneal immune privilege with a higher rate of rejection episodes after corneal transplantation. Furthermore, it is probable that Langerhans cells as potent antigen-presenting cells may also play an important role in the initiation and the progression of immune responses in various inflammatory corneal diseases.
Using the Octopus G1 program, we investigated the visual fields of amblyopic and healthy contralateral eyes in 21 patients with strabismic amblyopia and 14 patients with anisometropic amblyopia. All subjects had a visual acuity of 0.7-0.06. A central scotoma was detected in 85.7% of the patients with strabismic amblyopia and in 79% of those with anisometropic amblyopia. The mean maximal depth of central scotomas in subjects with strabismic amblyopia was 6.81 +/- 4.74 dB (mean +/- SD); in those with anisometropic amblyopia, it was 6.64 +/- 4.34 dB. This difference was statistically not significant. However, in patients with anisometropic amblyopia, the visual field indices MD (mean defect) and CLV (corrected loss variation) were significantly higher than in those with strabismic amblyopia (P less than 0.05 vs P less than 0.05); this was predominantly due to additional flat defects that occurred paracentrally and peripherally in subjects with anisometropic amblyopia. In both groups of patients, we found a significant negative correlation between visual acuity, on the one hand, and the maximal depth of the scotomas and the visual field indices (MD and CLV), on the other.
Carcinomas of the cornea have not yet been described in the literature. A 50-year-old man underwent keratoplasty because of corneal dystrophy. Microscopic examination disclosed a squamous-cell carcinoma which had spread over the entire cornea and just reached the limbus.
A carcinoma of the cornea is rare. A 48-year-old man underwent keratoplasty because of corneal dystrophy. Micro-scopic examination showed a squamous cell carcinoma that had spread over the entire cornea and had just reached the limbus. A conjunctival biopsy was performed. Histological analysis showed conjunctival tissue that was covered with normal epithelium. No carcinoma cells were evident.
The patient, who is now 60, had a nevus and areas of cystic changes in the conjunctiva in her right eye, which had been present from birth to the age of 59. In 1987, rapid tumor growth aroused suspicion that malignant change could be occurring and so the nevus as well as the area of the conjunctiva containing cystic changes were excised. Histological finding: conjunctival malignant melanoma, containing compressed (densely arranged) atypical cells with pleomorphic hyperchromatic nuclei and prominent nucleoli. The biopsy specimen of the conjunctiva showed a typical nevocellular nevus with large inclusion cysts of the conjunctival epithelium.
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A 87-year-old female patient with a squamous cell carcinoma of the conjunctiva was treated with local strontium-90 irradiation (with a so-called 'Dermaplatte'). In spite of a relatively low dosage, radiotherapy was followed by a corneal ulcer with consecutive rupture of the cornea. The cause of this unexpected perforation was, besides the effect of low-dose irradiation, probably a metabolic disorder of the cornea and a disturbance of the tear film due to the carcinoma which had spread on Bowman's layer of the cornea in an exophytic manner and was accompanied by a dense lymphocytic infiltration. An exenteration was performed and, at the last examination (1 year later), no local recurrence could be detected.
Dacryoliths are uncommon and there are only a few reports in the literature. In a patient with recurrent stenosis of the lacrimal drainage system a lacrimal stone (dacryolith) was removed from the lacrimal sac during dacryocystorhinostomy. A histological and immunohistochemical examination was performed and keratin antibodies could be detected. In a chemical analysis calcium, sulfur and some phosphorus were determined as major constituents.