Biomedical subjects
Publications and source records attributed to G Grabner.
For the examination of living corneal endothelium two techniques are at present available. The differences between them, with regard to postoperative usability, optical phenomena, magnification, cell counting artefacts and costs are discussed. The differences are illustrated by reference to clinical cases.
In 67 patients suspected to suffer from cerebral vascular disorders or arterial occlusive disease results of ophthalmodynamometry and ophthalmodynamography were compared with those of carotid angiography. Especially in patients with angiographically substantiated carotid stenosis the results of ODM and ODG were extraordinarily poor. The findings of ODM and ODG proved to be non indicative in 29 out of 35 cases. The authors discuss the possible reasons of these disappointing results.
Aqueous humor (a.h.) was sampled in 67 patients operated on for cataract by intracapsular lens extraction at the start and finish of surgery. Twenty eight of these patients received pretreatment with acetyl-salicylic acid (ASA), to a total of 2.5 g, beginning 18 hours prior to surgery. A serum sample was drawn immediately following the operation from 55 patients. Using radial immunodiffusion, albumin and IgG were measured in primary and secondary a.h. and in serum. The group pretreated with ASA showed a significantly smaller relative increase of IgG (P < 0.05). The increase of the proteins, however, showed no dependence on their serum-level and the only side-effect of the treatment was an unexplained rise in serum-albumin. The possible clinical application of patients with a high risk of postoperative complications is briefly summarized.
Histopathological changes following cyclocryokoagulation in a group of rabbits pretreated with acetylsalicyclic acid (ASA) were studied and compared with similar changes in a control group. As observed clinically, macroscopical and histological differences were only noted in the early phase after the procedure. In this phase, all operated eyes revealed an immense vascular response with edema, exudation and extravasation of blood cells. The treated animals, however, showed some reduction of tissue edema than the animals not treated. At a later stage there is an necrosis of the stroma with reduction of small vessels and tissue cells. The reparative process, tending to restore both epithelial and stromal lesions, begins already in the 3rd. week after cyclocryokoagulation. Neither the epithelial nor the stromal alterations differed significantly in any of the operated eyes at this stage. This indicates that ASA mainly affects an obviously prostaglandin-mediated acute vascular response. The disruption of the epithelial barrier may be aggravated by the subsequent stromal alterations, but does not seem to be influenced by ASA.
In 25 patients with primary and 24 patients with recurrent herpetic corneal disease the cell-mediated immunity to Herpes simplex virus antigen (type I) was measured using a leukocyte migration inhibition assay. After a period of one to 24 months 25 of the patients were tested again. The diagnostic possibilities offered by this method, especially in respect of control of immune-stimulating therapy, and its pitfalls are discussed.
A 21-year-old patient was struck by the pulse of a rangefinder laser (infrared laser). The massive pathologic changes on his macula are explained by the focusing effect of the refractive media. Secure location of the beam, the avoidance of reflective surfaces and absorbing screens are recommended as protective measures.
Thirty-eight patients with amaurosis fugax were examined ophthalmologically. In 12 of these cases carotid occlusion was diagnosed by ophthalmodynamography and Doppler ultrasonography of the orbital vessels. Angiographic substantiation was possible in nine of these patients. The pathognomonic importance of amaurosis fugax for occlusive carotid disease is clearly shown by these findings. The plasma concentration of platelet specific proteins was examined in 32 patients and found to be pathologically increased in 13 cases. Spontaneous aggregation of platelets and circulating platelet aggregates were only found in a few patients. Due to the lack of coincidence between the event of amaurosis fugax and the time when platelet function tests were made no definite conclusions may be drawn from these results. Yet disturbances of platelet function must be taken into consideration in the pathogenesis of amaurosis fugax.
The cortical layer of the vitreous body of the eye contains a homogeneous population of hyalocytes. These cells were prepared from human autopsy eyes under sterile conditions by incubating the vitreous gel in tissue culture medium containing 300 micrograms/ml hyaluronidase. With the use of trypan blue staining, 60% to 90% of the cells were viable; they stained strongly for an intracellular nonspecific esterase with alpha-napthylacetate as a substrate. This staining could not be inhibited by sodium fluoride. The hyalocytes showed adherence to glass and plastic surfaces and phagocytosed latex spheres of 1.1 micrometer diameter. On their surface, receptors for IgG and complement components could be demonstrated with a rosette-forming technique using sensitized sheep erythrocytes. All these features strongly support the assumption that hyalocytes are mature cells of the mononuclear phagocyte system.
The treatment of acute pancreatitis as currently practised in Austria was evaluated by means of a questionnaire mailed to all medical and surgical departments in Austrian hospitals. Fasting, analgesics and parenteral fluid therapy are applied routinely and proteinase inhibitors are used in nearly all hospitals. The efficacy of placing the pancreas at rest by withdrawal of oral fluids, nasogastric suction or antacids is variably assessed. Pharmacological inhibition of pancreatic secretion is achieved mainly by anticholinergics, whilst less often glucagon is prescribed. Antibiotic prophylaxis is widely applied. The main indications for surgery are complications and pre-existing biliary tract disease. These results are compared with the literature.
Using a direct assay of leukocyte migration inhibitory factor (LMIF), cell-mediated immunity to herpes simplex virus (HSV) antigen was measured in patients who had primary and recurrent ocular HSV infections. Those with primary and recurrent epithelial disease had a significantly lower production of LMIF than a control population than had had no herpetic infection for at least a year or longer (P less than 0.001). On the contrary, patients with deep stromal involvement and anterior uveitis showed significant migration inhibition with HSV antigen, similar to the one found in the healthy control group. The clinical and possible therapeutic implications of thes findings are discussed.
In 71 patients that underwent intracapsular extraction of the cataract it was possible to collect aqueous humor (a.h.) in sufficient quantities at the beginning and at the end of the operation. Using radial immunodiffusion albumin, IgG and alpha-1-antitrypsin were measured in the samples. In secondary a.h. huge variations in the concentrations were apparent. The primary permeability of the blood-aqueous barrier and the time between sampling had no influence on the relative increase of the proteins. No statistically significant difference was found between normotensives and hypertensives and patients with or without myopia of higher degree (over 6 diopters). The relative increase of proteins according to their difference in molecular weight followed the same pattern as described for anterior uveitis. In patients for whom an enzymatic zonulolysis with trypsin was used for the extraction, the relative increase of IgG was significantly smaller than in those that did not receive this treatment (P less than 0.005). The possible sources contributing to the formation of secondary a.h. are discussed.
Prostaglandin mediated transient increase in intraocular pressure following cryokoagulation of the ciliary body in rabbits was completely inhibited by preoperative administration of Aspisol (D, L-Lysin-mono-(acetylsalicylat)). To avoid additional increase in intraocular pressure in patients chosen for cyclocryotherapy, pretreatment with Aspisol could prove to be effective.
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51 patients with renal transplants were examined ophthalmologically 31,1 (1--77) months after the transplantation. 80,4 p. c. showed ocular complications: cataract formation in 43,1 p. c. of the patients examined and increased intraocular pressure values between 22 and 30 mm Hg in 3 patients are to be attributed to the systemic immunosuppressive therapy. Further ocular changes were recurrent subconjunctival haemorrhages due to increased vascular rigidity, calcium phosphate deposits in the conjunctiva due to persistant secondary hyperparathyroidism and fundus changes (pigmentary irregularities in the foveal regions, narrow arterial vessels). Although marked arterial hypertension was observed in 21 patients after the transplantation, no signs of hypertensive retinopathy could be found. Despite the high incidence of ocular complications after renal transplantation the risks of immunosuppressive therapy must be considered as tolerable: cataract formation and increased intraocular pressure do not impair the positive effect of renal transplantation on ocular functions. Regular ophthalmological control examinations of renal transplant patients are advisable.
In 32 patients with clinically, biochemically and histologically proven chronic aggressive hepatitis, HBsAg, HBsAb, HBcAb and HA-Ab were determined by radioimmunoassays and HBeAg and HBeAb were estimated by immunodiffusion. HBsAg was positive in 18 patients [57%], HBcAb were found in 23 patients [72%], HBsAg and/or HBcAb were detected in 26 patients (82%). The incidence of HA-Ab was 88%, similar to the frequency of HA-Ab found in healthy blood-donors. The aetiology of chronic aggressive hepatitis was associated with hepatitis B in 82%, and with autoantibodies in 6% of our patients, while in 12% the aetiology remained cryptogenetic.
There cases of interstitial linear keratitis are described. A linear infiltration was found in the anterior part of the corneal stroma, which remained stable throughout the observation period and became a dense scar. The disease shows frequent recurrencies, the etiology remains unknown. All three patients treated were of young age.