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Biomedical subjects

J Arends

Publications and source records attributed to J Arends.

At least 235 records · Page 13Linked to original sources

Interaction of fibroblasts and polymer surfaces: relationship between surface free energy and fibroblast spreading.

Cell spreading and cell division rates of a transformed line of mouse lung fibroblasts were studied on various polymer surfaces in the presence of serum proteins. The bare polymer surfaces, as well as the protein-coated surfaces, were characterized by their polar (gamma ps) and dispersion (gamma ds) surface free energies. Cell spreading appeared to be dependent on the polar surface free energy. Cell spreading is low when the gamma ps of the bare surface is lower than 5 erg cm-2; marked spreading occurs when gamma ps is higher than 15 erg cm-2. A similar relationship was found between cell spreading and polarity of the protein-coated surfaces, although less pronounced than for the bare surfaces. Cell spreading appeared independent of the dispersion surface free energy. Cell division rate was the same on all surfaces tested.

Animals↗

Biochemical markers for testicular germ-cell tumors in relation to histology and stage: some experiences from the Danish testicular cancer (DATECA) Study from 1976 through 1981.

The DATECA Project was started in January 1976 and includes all patients with testicular cancer in Denmark. During the first 6 years, 1246 patients entered the joint protocol for histology, staging, management, and clinical use of tumor markers. Only 746 DATECA patients fulfilled the claims for being ideally monitored with preoperative as well as postoperative serologic marker determinations. The overall prevalence of marker positivity, that is, elevated preoperative values of alpha-fetoprotein (AFP) and/or human chorionic gonadotrophin (HCG) was 8% for patients with seminoma and 63% for patients with nonseminomatous disease. The prevalence of increased marker concentration in serum was correlated to stage (higher prevalence in higher stages) and to prognosis (marker-negative patients had a better prognosis than did marker-positive patients). An increased concentration of AFP or HCG was correlated with the presence of a primary endodermal sinus tumor and choriocarcinoma component, respectively.

Alkaline Phosphatase↗

Morphology of enamel surfaces treated with topical fluoride agents: SEM considerations.

Three topical fluoride agents deposited surface coatings of different morphology and thickness on intact human enamel surfaces. The agents studied were an acidic silane fluoride lacquer, a neutral NaF lacquer, and an APF gel. Each agent reacted with the enamel surface differently, producing its own distinctive etching pattern. The smallest particles observed in the surface coatings were from 20 to 30 nm in diameter and appeared to have indistinct morphologies. They often agglomerated into spherical globules ranging from 1-3 micron in diameter.

Acidulated Phosphate Fluoride↗

Influence of radial TEM distortion on the accuracy of lattice parameter determinations of apatites: a comparison of four electron microscopes.

Lattice fringe distances of synthetic hydroxyapatite were measured quantitatively in four different TEM microscopes as a function of the position with respect to the optical axis. Using the accurately known "a" value of this apatite from X-ray diffraction, the maximum radial distortion in the image planes can be determined in various positions. For the Philips EM 400, EM 300 (1) and EM 300 (2) and JEOL 200 CX the maximum radial distortion was found to be 1.0%, 0.8%, 1.5% and 0.5%, respectively. In accurate lattice parameter determinations of mineral and mineral phases in biological tissues by means of TEM; this radial distortion is an important parameter to take into account.

Crystallography↗