[In vitro and in vivo studies of local disinfection and wound healing]. / In-vitro und In-vivo-Untersuchungen zur Lokaldesinfektion und Wundheilung.

Wound healing represents a dynamic process of increasing scientific interest, especially with the detection of the different growth factors. Economic aspects are also of importance in the investigation of substances used for wound healing. In Germany 25% of all patients (ca. 1 million) with severe chronic venous insufficiency have crural ulcers. The influence of bacterial infection of crural ulcers is controversial. There is no doubt that the quantity of bacteria is of importance. Local antibiotic treatment is difficult, as most of the substances used are known to inhibit wound healing. In vivo and in vitro investigations showed, that chiniofon-containing antiseptic has a bacteriostatic function. Additionally it was shown, using cultures of fibroblasts, that chiniofon-containing antiseptic does not inhibit the growth of fibroblasts, whereas PVP-iodine solution, a widely used antiseptic, clearly reduces the growth of fibroblasts. The good clinical results in the treatment of acute and chronic radiation damage indicate that chiniofon-containing antiseptic may have antiflammatory activity.

[The growth behavior of mouse fibroblasts on intraocular lens surface of various silicone and PMMA materials]. / Wachstumsverhalten von Mausfibroblasten auf Intraokularlinsenoberflächen aus verschiedenen Silikon- und PMMA-Materialien.

Experience with intraocular lenses (IOL) made of PMMA dates back ca. 40 years, while silicone IOLs have been in use for only about 10 years. The biocompatibility of PMMA and silicone caoutchouc was tested in a comparative study investigating the growth of mouse fibroblasts on different IOL materials. Spectrophotometric determination of protein synthesis and liquid scintillation counting of DNA synthesis were carried out. The spreading of cells was planimetrically determined, and the DNA synthesis of individual cells in direct contact with the test sample was tested. The results showed that the biocompatibility of silicone lenses made of purified caoutchouc is comparable with that of PMMA lenses; there is no statistically significant difference. However, impurities arising during material synthesis result in a statistically significant inhibition of cell growth on the IOL surfaces.

[Comparative studies of toothpastes and toothpaste ingredients in biological systems: 1. Can various toothpastes be differentiated by relative biological effectiveness in cell culture studies?]. / Vergleichende Untersuchungen von Zahnpasten und Zahnpasten-Bestandteilen in biologischen Systemen: 1. Lassen sich verschiedene Zahnpasten im Zellkulturversuch bezüglich ihrer biologischen Wirkung differenzieren?

The cytotoxicity of 15 commercial toothpastes was examined in human epithelial cell cultures. The following parameters were evaluated: protein concentration, DNA-synthesis, cell morphology and autoradiography. In comparison to the control cell culture, one toothpaste had no influence on the cell growth at all. The other pastes caused a more or less strong growth inhibition, which also depended on the concentration of the toothpaste suspension. The presented investigations showed that the cytotoxicity tests applied to toothpastes yielded a good validity.

[Lens epithelium necrosis factor for prevention lens opacity]. / Linsen-Epithel-Nekrose-Faktor (LENF) zur Nachstarverhütung.

Posterior capsule opacification is a common postoperative complication after extracapsular cataract extraction and lens implantation. If the patient's visual acuity is reduced markedly, a capsulotomy with a Nd-YAG laser may become necessary. Various attempts have been made with the aim of developing an injectable solution capable of damaging the epithelial cells of the capsule bag irreversibly and thereby avoiding posterior capsule opacification. This solution should be applied for a short time during the operation. In tissue culture we tested the influence of two injectable solutions [lens epithelial necrosis factor (LENF)] and aqua bidest. on cellular growth. Balanced salt solution served as control. We used human epithelial carcinoma cells, type HEp-2. The results were evaluated by vital staining (ethidium bromide and acridin orange), hemotoxylin staining, autoradiography and measurement of protein and DNA synthesis. The results showed that LENF is capable of damaging 100% of the epithelial cells irreversibly if it is applied for 20 s or longer. The influence of each of these solutions was tested on 20 human capsular flaps, which were excised during the operation. The flaps were immersed for 30 s in the different solutions. Vital staining of these flaps led to the following results: LENF causes a 100% cell damage of all epithelial cells of the capsular flaps. No vital cells remained. On the other hand Aqua bidest. cannot guarantee 100% cell damage of the capsular flap epithelia. Sixty percent of the capsular flaps treated with aqua bidest, showed differing amounts of remaining vital cells.

[Human gingival fibroblast cultures for biological intra-oral material testing]. / Die Zellkultur humaner Gingivafibroblasten zur biologischen Prüfung von in der Mundhöhle verwendeten Materialien.

Cell cultures are useful screening methods for biocompatibility tests, as they provide information on the effects of test material on their metabolism. Primary cultures of human gingival fibroblasts play a special role, because they are organ-specific and because their metabolic state is virtually the same as that of in vivo cell material. Their characteristic growth pattern makes them excellent candidates for testing toxicity and stimulatory factors. Four methods were used for validating the data obtained. Possibilities of culturing these highly specialized cells are shown, techniques for assessing the cytotoxicity of test materials are presented and discussed.

[Characteristics of human dental pulp cells in cell cultures]. / Charakteristik menschlicher Pulpazellen in der Zellkultur.

The generation time and the division rate were measured with routine methods of cell culturing. The conditions contributing to the stagnation of growth were examined; the synchrony of the growth process was investigated. The biochemical composition of the cells was assessed via colorimetry and then compared with other cell systems. The cell culture examined may be used to test capping materials; only cells up through the eighth generation however should be utilized.

[Aging in human gingival fibroblasts in cell culture. A contribution to the understanding of proliferating inflammations]. / Alterung von menschlichen Gingivafibroblasten in der Zellkultur. Ein Beitrag zum Verständnis der proliferierenden Entzündung.

Proliferation of gingival fibroblasts was studied in cell cultures under controlled conditions. Biopsies taken from 12 patients of different ages were analyzed in regard to the length of the generation cycle and the ability to produce subcultures. Cultures from elderly individuals showed progressive, longer generation cycles than cultures from younger patients. The ability of the gingival cultures from elderly patients to produce subcultures is considerably less than those from young individuals. Apparently gingival fibroblasts are subject to aging processes in the patient himself and in the cell population within the cell culture. The growth characteristics differed depending on the location on the gingiva; the interdental papilla grow better cultures than do free and attached gingiva.

Bleomycin: effect on satellite DNA in mouse fibroblasts.

The effect of Bleomycin on the semiconservative replication of mouse nuclear DNA has been studied. When asynchronously dividing mouse fibroblasts (L-cells) were grown in the presence of 5-bromodeoxyuridine (25 mg/l medium) for 18 h, three hybrid DNA bands with densities of 1.722, 1.752, and 1.761 kg/l appeared after caesium chloride density gradient centrifugation of nuclear DNA. In cells exposed to Bleomycin (100 mg/l) however, replication of satellite DNA is more strongly inhibited than is the replication of the main band DNA; preferentially the thymidinerich hybrid duplex at 1.761 kg/l could no longer be detected.

Effect of bleomycin on the fine structure of mouse fibroblasts.

Asynchronously dividing mouse fibroblasts (L-cells) treated with the antitumour antibiotic Bleomycin show various rather specific morphological alterations. Many of the cells exposed to bleomycin assume a more or less epitheloid cell shape and are larger than untreated cells; in addition to an increase in nuclear size these cells often contain multiple nuclei. In most of the cells nuclei show an almost complete loss of peripheral condensed chromatin. The nucleolar hypertrophy initially observed is followed by a shrinkage and segregation of the nucleolar components. The cytoplasmic alterations include dilatation of the cisternae of the rough endoplasmic reticulum as well as an increase of free, non membrane attached ribosomes, often arranged in spiral- and rosette-shaped polysomes; they are not specific for bleomycin.