Biomedical subjects

B Wolters

Publications and source records attributed to B Wolters.

20 records · Page 2Linked to original sources

PubMedDate not supplied

Physicochemical surface properties of various intraocular lenses.

PURPOSE: It is of major interest to understand how intraocular lens (IOL) surfaces interact with aqueous humor or tissues after implantation. Important parameters to describe the physicochemical surface properties are the contact angle and critical surface tension. Therefore, we performed measurements of the contact angle and critical surface tension of several commercially available IOLs. SETTING: Department of Ophthalmology, Johannes Gutenberg University, Mainz, University Eye Hospital, Tübingen, and Max Planck Institute for Polymer Research, Mainz, Germany. METHODS: A total of 17 commercially available standard quality IOL types (6 of each) of different materials from several manufacturers were studied. Scanning electron microscopy and contact angle measurements using the sessile drop method were made. RESULTS: The sessile drop method differentiated all materials based on their surface forces. The contact angle (mean +/- SD) ranged from 56.5 +/- 3.8b 3. CONCLUSION: Contact angles differed between the IOLs depending on the IOL material with the lowest contact angle in the heparin-surface-modified IOL. The contact angle measurement method generates useful information about the material surface and its potential biomaterial interactions.

Acrylic Resins↗

PubMedDate not supplied

Dvelopment of the Harderian gland in the chicken: light and electron microscopic investigations.

The Harderian gland of the chcken develops from epithelial cones of the conjunctiva between the 11th and 12th day of embryonal life. The development of the organ proceeds in two phases. During the stage of epithelial development (days 13 to 17 of embryonal life) the acinar epithelium differentiates into a lumen-adjacent glandular epithelium, and a separate layer of basal epithelial cells. This basal layer is initially compact but later forms a loose meshwork. The basal cells differ from the myoepithelial cells found in the Harderian gland of rodents by virtue of their smaller number of myofilaments; and they resemble the reticuloepithelial cells in the Bursa of Fabricius. On days 17 and 18 of embryonal life the interstitial tissue is invaded by eosinophils and by small 'blasts', up to 4 microns in diameter, both of vascular origin. Between days 17 and 20 the glandular epithelium undergoes secretory transformation. At the time of hatching (day 21), the secretory function is fully developed. The mode of secretion is partly apocrine, partly merocrine. During the following phase of plasmacellular development (from day 17 of prenatal until day thirty of postnatal life) interstitial plasma cells are formed from the immigrant small 'blasts'. Their number increases until the fourth week after hatching; thereafter the plasma cell population remains stable.

Age Factors↗