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Biomedical subjects

K Andersen

Publications and source records attributed to K Andersen.

At least 235 records · Page 13Linked to original sources

Purification and characterization of guinea-pig intestinal brush borders.

The purification of guinea-pig intestinal brush borders by a rapid sucrose-gradient-centrifugation step is reported. A 29-fold increase in the maltase/DNA quotient indicates considerable purification of the brush borders from nuclei. The biological activity of the brush borders was well preserved, as demonstrated by a high recovery of human gastric-juice-mediated uptake of 57Co-labelled vitamin B-12; homogeneity and purity were confirmed by scanning electron microscopy. Both the morphological appearance and biological activity were unchanged after prolonged storage in glycerol.

Animals↗

Studies of an acrosomal defect in spermatozoa from a platinum fox.

An acrosomal defect in the spermatozoa from a platinum fox was studied under light- and electron microscopy. The defect, occurring in about 40 % of the sperm cells appeared under phase-contrast and bright-field microscopy as a knob-like irregularity, mostly rounded or slightly triangular in outline and situated in the apical part of the sperm head. Electron microscopy of the sperm head revealed a marked deviation from the normal development of the acrosome. In most of the cases this structure contained a large membrane bounded vacuole filled with numerous small vesicles and some membranous material. In spermatids studied in the cap-phase, the developing acrosome exhibited a high degree of abnormal morphology, indicating that the development of the defect must have started rather early during the formation of the acrosome.

Acrosome↗