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Biomedical subjects

H Bleckmann

Publications and source records attributed to H Bleckmann.

At least 73 records · Page 4Linked to original sources
PubMed1985

Histological findings in angulated posterior chamber lenses.

The histological observations of 6 cadaver eyes containing a SIMCOE posterior chamber lens are reported. Reduction of loop diameter 10 months after implantation is demonstrated. The cellular response of the local tissue is demonstrated with and without the loop contact. In long term follow up the loop support in the sulcus rim was seen to lead to a canal formation within the ciliary body. Scanning electron microscopy revealed a compact cover around the peripheral end of the loops which showed tight contact to the synthetic material.

Adhesiveness↗
PubMed1984

[Indications and contraindications of beta blockaders in the treatment of glaucoma].

Local administration of beta-blockers to the eye has proven effective in the treatment of chronic simple glaucoma. However, varying degrees of impaired ventilation, even to the point of being life-threatening, have been reported. The effect of 1% pindolol and 0.5% timolol eye-drops, twice daily applied locally to the eye, on eyeball pressure and airway resistance was measured in 19 patients with chronic glaucoma. Compared with timolol eye-drops, pindolol had little effect on ventilatory functions, i. e. there was a significant difference between them. But the two preparations had similar effects in lowering eye-ball pressure. The likely explanation of this divergent action is the intrinsic sympathomimetic activity of pindolol.

Adrenergic beta-Antagonists↗
PubMed1984

Effect of bicarbonate, pH, methazolamide and stilbenes on the intracellular potentials of cultured bovine corneal endothelial cells.

Micropuncture of cultured bovine corneal endothelial cells led to registrations stable for hours. Intracellular potentials were mainly in the range of -40 to -55 mV, average 46.3 +/- 0.6 mV (SEM). Changes of extracellular [HCO-3] led to voltage transients, their amplitude depending logarithmically on [HCO-3] with a mean slope of 37.3 +/- 8.8 (SD) mV. After removal of bicarbonate/CO2, a steady-state depolarization was seen. This steady-state depolarization, but not the voltage transients, could be reduced by 1 mM Ba++. After removal of bicarbonate, the voltage response to changes of extracellular potassium was reduced. Alteration of pHi induced by permeable buffers (butyrate, glycodiazine and ammonium) also resulted in voltage transients, internal acidification being correlated with a hyperpolarization, and internal alkalinization with a depolarization. Also changes of external pH caused voltage responses, alkalinization causing a hyperpolarization, acidification a depolarization. Methazolamide, an inhibitor of carbonic anhydrase, as well as stilbenes (SITS or DIDS) caused a reduction of the voltage response to HCO-3 and pH. Their effects were additive. It is suggested that corneal endothelial cells possess one or two electrogenic transporters for HCO-3 or related species, one of which is inhibitable by stilbenes.

Animals↗
PubMed1984

Glycosaminoglycan metabolism of cultured fibroblasts from bovine vitreous.

Glycosaminoglycan metabolism of cultured vitreal cells of bovine origin was investigated with the following results: Cultured vitreal cells distributed the synthesized macromolecules after [35S] sulfate incorporation into the culture medium (extracellular pool), the membrane-bound proteoglycans (pericellular pool), and within the cells (intraocular pool). No extracellular plateau was reached after 3 days; the pericellular and intracellular pools showed a steady state of radioactivity after 48 and 24 h, respectively. Pulse-chase experiments exhibited a rapid turnover of intracellular polysaccharides and a slower metabolism of pericellular polymers. Pinocytosis, adsorption and degradation of vitreal and corneal cell secretion by vitreal cells were observed to a comparable extent. Chondroitin sulfate isomers and heparan sulfate could be detected in minor proportions. The relevance of glycosaminoglycan metabolism in the replacement of cultured vitreal cells into the vitreous cavity is discussed.

Animals↗
PubMed1984

[Complications following implantation of the Simcoe lens of the posterior chamber].

After the introduction of phacoemulsification and ECCE at the Charlottenburg eye clinic of the Free University of Berlin, Simcoe posterior chamber lenses have been implanted there routinely since May 1982. Up to August 1983, 1124 posterior chamber lenses had been implanted, all of the Simcoe type. The advantages of posterior chamber lens implantation having been dealt with elsewhere, the authors point out the complications of the procedure in this paper. The complications seen were cyclitic reactions, including hypopyon in 6 patients. In one patient a rhegmatogenic retinal detachment was diagnosed 2.5 months after phacoemulsification and implantation of a Simcoe lens. Decentered lenses were found in 3 patients, in one of them after phacoemulsification of a radiogenic cataract with capsulotomy. In 2 patients the posterior capsule ruptured during insertion of the lens but the lens remained lodged in the sulcus, so that it did not have to be removed. Since March 1983 all Simcoe posterior chamber lenses have been fitted (in a total of 571 eyes) with loops angled 10 degrees forward, as suggested by the authors. Iris capture syndrome was found in 12 patients (2.2%) of a group in which 553 lenses without angled loops had been fitted. The condition was not found in any of the patients to whom lenses with angled loops had been fitted.

Adult↗
PubMed1983

Influence of dextran macromolecules on the glycosaminoglycan metabolism of cultured corneal stroma and keratoconus fibroblast.

The addition of dextran macromolecules to the incubation medium at 1% and 10% concentration does not cause any alteration of sulphated glycosaminoglycan synthesis or its distribution within the various cell compartments. This is in contrast to observations on a serum-free and dextran-enriched medium in which glycosaminoglycan distribution of stored corneal tissue remains normal and the concentration of keratan sulphate is maintained. The mechanism of this action is unknown. Some experimental findings of the influence of dextran upon cell metabolism are discussed.

Cells, Cultured↗
PubMed1983

[Pulsating macroaneurysm of a retinal arterial branch].

Pulsating macroaneurysms of retinal vessels have so far been described only as isolated cases. The case reported here was a 72-year-old female patient with systemic hypertension and suspected Raynaud's disease. The pulsating macroaneurysm was only observed for a few days; subsequently it fibrosed and an arterial branch occlusion was demonstrated. Retinal macroaneurysms have been mentioned in combination with aneurysmal cerebral vessels in hypertonic patients, suggesting generalized vessel wall disease. This patient's central visual acuity was hardly affected, even after a number of months, and photocoagulation treatment was thus unnecessary. Such treatment for retinal macroaneurysms should be considered in each case individually, depending on the extent of bleeding and edema.

Aged↗
PubMed1982

Rare complications in a case of generalized meningococcal disease: immunologic reaction versus bacterial metastasis.

A 14-year-old girl was suffering from meningococcal sepsis with initial endophthalmitis. During a secondary and prolonged fever attack including aseptic meningitis, temporary complications such as pericarditis, arthralgic pains, headache and localized phlebitis were observed. There were three relapses of pericarditis within nine months. Their course was benign. The discussion deals with the pathogenesis of these complications as metastatic and immunologic reactions. The possibility of these complications should be considered during diagnostic investigation and therapeutic treatment.

Adolescent↗
PubMed1982

[Morphological findings in the rabbit cornea after tear gas cauterization (author's transl)].

Solutions of various concentrations of chloracetophenone (dissolved in 1, 1, 1, trichlorethane) were trickled on the corneas of rabbits. The substance was either applied to the center or to the limbus, or simultaneously to the center and limbus of the cornea. After surgical removal of the cornea on day 21, the alterations were examined by a light microscope. When chloractephenone was applied to the middle of the cornea, signs of intensified epithelial regeneration were observed, even to the point of a severe granulating and necrotic infection with ulceration. The severity of these changes depended on the concentration used and showed that repair of a corneal defect had been attempted. The same changes were observed when the same concentrations of chloracetophenone were applied to the limbus, but with greater severity. Some of these alterations led to perforation of the cornea when the substance was applied to center and limbus. These results are discussed in reference to the correlation of the changes seen in animal tests to those in the human eye.

Acetophenones↗
PubMed1981

[Corneal damage caused by chloracetophenone].

Chloracetophenone solubilized in 1,1,1-trichlorethan was applied in different concentrations to the rabbit cornea. Applications were made to the centre of the cornea as well as to the limbal area and also in an experiment with centrallimbal burning. The ensuing stromal scarring was related to the absolute quantity of applied chloracetophenone, and burning of the limbal area seemed to be more effective than central applications.

Animals↗
PubMed1981

Examination of the fast oscillation of the corneoretinal potential under clinical conditions.

The "fast oscillation" of the corneoretinal potential can be precisely examined by means of cyclic light stimuli and an automatic measuring device. This new procedure is carried out during the period of adaptation as part of the usual EOG-test. Normal values and some clinical findings are presented. The fast oscillation may provide additional information when compared with EOG and ERG results.

Aged↗
PubMed1981

[Clinical aspects of tear gas burns on the cornea (author's transl)].

A report on the consequences of tear gas burns on the cornea and other extraocular and intraocular injuries sustained by 45 patients. Forty burns were caused by pistol shots, while five of the patients treated had burns from tear gas sprays. This report covers the distribution of the patients according to age and sex and described changes in central visual acuity. Differences in the type of injury according to the cause (explosive or aerosol) can be demonstrated: aerosol burns had less severe consequences. Twelve of the 45 patients were followed up.

Adolescent↗
PubMed1981

[Accidental laser coagulation of the macula (author's transl)].

During experimental studies with Q-switched laser radiation a laser beam with an impulse energy of 100 mJ reached the left eye of a patient. Dense vitreal hemorrhage developed; later fundus evaluation revealed coagulation of the macula with circular subretinal bleeding. Six month later a scar with retinal folds was observed at the posterior pole; the visual acuity was 0.1. The accident is compared with previously reported cases.

Accidents, Occupational↗