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Biomedical subjects

J Obenberger

Publications and source records attributed to J Obenberger.

At least 109 records · Page 6Linked to original sources
PubMed1975

Ring-shaped alkali burns of the rabbit cornea. Epithelial and endothelial changes.

Rabbit corneas were burned by touching their surfaces with rings of Whatman No. 1 chromatographic paper soaked in 1N NaOH. The corneal epithelium and endothelium were studied by impregnating flat sections with McGovern's and Jabonero's silver stains. Immediate destruction as well as regeneration of both cellular layers is described.

Animals↗
PubMed1975

Alkali burns of the rabbit cornea. I. A histochemical study of beta-glucuronidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase.

In alkali burned rabbit corneas activities of beta-glucuronidase, N-acetyl-beta-D-glucosaminidase and acid beta-galactosidase were studied histochemically in various time intervals after the traumatization. The technic with semipermeable membranes was employed. Within four days after the injury enzyme activities in the traumatized area were almost lacking. The corresponding activities in the unaffected part of the cornea were within the norm. On the 7th day enzyme activities were on an increase (but still subnormal) in the traumatized area. This area was surrounded by a zone of keratocytes with high levels of enzyme activities. This was particularly remarkable in keratocytes subjacent to the epithelium. The activation of all enzymes studied was present in the basal layer of the epithelium and in the endothelium as well. On the 14th day enzyme activities in the traumatized area were nearly restored and on the 32nd day they could not be distinguished from the normal cornea. Beta-galactosidase displayed a relatively maximal increase in the activity of all enzymes investigated.

Acetylglucosaminidase↗
PubMed1975

Alkali burns of the rabbit cornea. II. A histochemical study of glycosaminoglycans.

In alkali burned rabbit cornea the stainability of glycosaminoglycans in cold microtome setions was investigated. Staining by Alcian blue in 3% acetic acid, Alcian blue in various MgCl2 concentration and toluidine blue (pH 4.5) was employed. From the 1st to the 4th experimental day the intensity of reactions was decreased. This is most probably due to an increased hydration of the corneal stroma. On the 7th day hydration was markedly suppressed and reached nearly the normal level. In this time interval a decreased stainability of glycosaminoglycans was seen accompanied by a complete loss of staining in the marginal zone. On the 14th day the stainability in the traumatized area began to restore and in the marginal zone appeared. On the 32nd day the staining intensity of both areas was normalised, however when lower concentrations of MgCl2 were used; in the presence of higher concentrations of MgCl2 the decreased staining intensity persisted and points to a lower sulfatation of glycosaminoglycans. This was particularly remarkable in the area bordering the injured zone. This decrease runs parallel to the increased activities of acid glycosidases (especially of acid beta-galactosidase) which were reported previously.

Alcian Blue↗
PubMed1975

In vitro estrone-estradiol-17beta interconversion in the cornea, lens, iris and retina of the rabbit eye.

Estrone and estradiol-17beta were incubated with various eye tissues of female rabbits. The interconversion of both estrogenes by the action of 17beta-hydroxysteroid dehydrogenase decreased in the sequence cornea, iris, retina, and lens. In a smaller yield estradiol-17alpha was also formed from estrone. The cornea seems to be an active estrogen-metabolizing tissue. The role of estrogens and progestogens in the tissues of the anterior eye segment is briefly discussed.

Animals↗
PubMed1975

Alkali and acid burns of the rabbit eye: uptake of intravenously injected Na125I and Na131I into the cornea and iris.

Rabbit eyes were burned either with 1 N sodium hydroxide or 1 N hydrochloric acid. In a previous part of the study (Obenberger and Babický, 1974) authors measured the aqueous flow using intravenous injections of Na125I and Na 131I. In the present study the uptake of iodine into the cornea and iris is investigated in the same eyes. Caustic injuries of both types initially cause changes in the specific activity of the aqueous affecting the uptake of iodine into the examined tissues.

Animals↗
PubMed1975

Alkali and acid burns of the rabbit eye: measurement of aqueous flow by means of intravenously injected Na-125 I and Na-131I.

Rabbit eyes were burned either with 1N NaOH or 1 N HC1. On the fifth day following the injury, aqueous humour flow was determined according to a method originally described by Becker (1962), using intravenous injection of Na-125I and Na-131I in different time intervals. In alkali-burned eyes the main finding was stoppage of the aqueous humour flow, probably due to obstruction of outflow channels. In acid-burned eyes the significantly elevated diffusion out of the eye was probably caused by altered function of the highly irritated and hyperemic iris. Results confirmed the previous findings achieved by the rate of disappearence of 14-C-glucose injected into the anterior chamber of the burned eyes.

Animals↗