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Biomedical subjects

O Hockwin

Publications and source records attributed to O Hockwin.

At least 73 records · Page 4Linked to original sources
PubMed1989

Biochemical analysis of bovine lens sections obtained by a new sectioning device.

One mm thick layers were reproducibly sliced from the punched-out inner cylinder of bovine lenses. The layers were obtained by a special designed freeze-sectioning device. Biochemical analysis of these layers revealed a detailed picture of the lenticular distribution of the amount of water-insoluble and urea-insoluble fractions. Furthermore, the distribution of the content of glucose, fructose and sorbitol was established. The results clearly show the usefulness of a microsectioning device to obtain layers for subsequent biochemical analysis which may lead to a comprehensive understanding of age- and/or cataract-related alterations within one lens.

Aging↗
PubMed1989

Distribution of clobetasone in rabbit eye tissues after topical application.

This study describes the bioavailability of Clobetasone, which is topically applied as an anti-inflammatory drug. Right eyes of Chinchilla rabbits received Clobetasone eye drops 3 times daily over a period of consecutive 14 days. 30 min up to 96 h after the last application animals were killed at different times and the eyes removed immediately. Nine different eye tissue samples were prepared for Clobetasone estimation by radioimmunoassay (RIA) using 3H-labeled Clobetasone and an antibody directed against Clobetasone. Results indicate that Clobetasone penetrates relatively fast into the different eye tissues. The concentrations are different in the various tissues and show a relationship to the distance from cornea to vitreous. Concentrations decline in the following order: cornea greater than conjunctiva, sclera, iris (200 ng/g) greater than lens, vitreous, aqueous humour (5-15 ng/g). In all samples investigated Clobetasone levels decrease with time. No accumulation of the drug has been measured at any time. Clobetasone levels in the left, untreated eye, indicate that the compound has a small systemic resorption.

Administration, Topical↗
PubMed1989

[Scheimpflug photography of the lens].

The introduction of Scheimpflug photography of the anterior eye segment, the construction of appropriate equipment, and the development of procedures for image analysis have decisively influenced clinical and experimental research on the anterior eye segment. The most important field of application is measurement of the light-scatter in the lens from which conclusions on lens transparency can be drawn. Information on the different transparency properties in the individual lens layers was obtained for the first time by means of investigations on lens transparency in relation to age. These data permit early recognition of pathological changes in lens transparency as the data were obtained from rather large groups of patients, the classification characteristics for the localization of certain opacifications could be determined objectively and thus provide the fundamental conditions for epidemiological investigations into a possible relationship between certain risk factors and types of opacification. Due to the high reproducibility of the photographic techniques, the method was speedily accepted for long-term investigations on lens transparency, some of which were sometimes performed over a period of several years. Application of the method within the scope of drug testing is already being requested today by the authorities concerned. The procedure has also been accepted for experimental cataract research. The possibility of early detection of the processes of opacification and their respective locations in the lens can now be biochemically analyzed.

Cataract↗
PubMed1988

Effect of an aldose reductase inhibitor, AL-1576, on the development of UV-B and X-ray cataract.

The effect of an aldose reductase inhibitor, AL-1576, on the development of UV-B and X-ray-induced cataract was studied with 100 female Brown-Norway rats. Histological studies were made with 32 eyes. A new histological procedure enabled detailed information on UV or X-ray-induced impairment on the lens, as well as on the potential efficiency of anticataract drugs. No definite effect of the aldose reductase inhibitor, AL-1576, on the development of UV or X-ray-induced cataract could be found. It may be concluded that AL-1576 cannot prevent damage caused by irradiation, like that of other oxidative influences. Disadvantageous effects of AL-1576 on the lens could be excluded.

Aldehyde Reductase↗
PubMed1988

[Clinical aspects and experimental findings in so-called senile cataracts. Determination of status].

In this article the authors review the present state of our knowledge concerning senile cataract. Clinical observations, frequencies and prognosis, biochemical and biometrical results, etiology and pathogenesis as well as aspects of cataract epidemiology are presented. The available information indicates that the term "senile cataract" comprises a multiplicity of morphologically different types of opacities all characterized by unique properties. With respect to clinical relevance and for research purposes it is obvious and essential to replace the term "senile cataract" with more precise definitions appropriate to the type and localization of the opacity.

Aged↗
PubMed1988

Cataract and health status: a case-control study.

Data from 97 cataract patients and 105 normal controls with ages less than 67 years were collected with respect to sex, age, disease status, drug intake, and blood chemistries. The statistical method of fitting log-linear models was used to determine the association between the case-control indicator variable and the other variables. The following variables were shown to be important and to associate independently with the risk of developing cataracts: age, allergy, diabetes, hypotension, hypertension, use of analgesics and coronary disease.

Adult↗
PubMed1988

Image analysis of Scheimpflug negatives. Comparative quantitative assessment of the film blackening by area planimetry and height measurements of linear densitograms.

Evaluation of various long-term studies on changes of different lens opacities, as had been rendered possible by microdensitometric image analysis of the film blackening of Scheimpflug photographs, showed that only in a few special cases an extension of the opacification to adjacent lens layers is to be expected within the observation period of 2-3 years. This means that one of the reasons for evaluating the densitometer curve by area planimetry is no longer valid and may be neglected. A further advantage of the measurement of film blackening by height evaluation (height of densitometer deflection above baseline, i.e., noise level) is the fact that it is highly independent of subjective factors and, therefore, ensures a far better reproducibility with respect to data acquisition. The results of both evaluation procedures, obtained by evaluating the identical film material (2 photoexaminations) of 14 volunteers, are presented, and the advantage of height measurement as opposed to planimetry is demonstrated.

Cataract↗
PubMed1988

Alterations of lens metabolism with experimentally induced cataract in rats.

Rat lenses with experimentally induced cataract (either by naphthalene or by streptozotocin) were analyzed biochemically. Both noxae had some effects in common. Water-soluble protein and aldose reductase activity decreased, and glucose-6-phosphate dehydrogenase, phosphofructokinase and glutathione reductase activity increased. A specific effect of streptozotocin was the rise in glucose, fructose and sorbitol. A specific effect of naphthalene was increased amounts of water-insoluble protein.

Animals↗